PC Online 1997 January/PCO0197.ISO/filesbbs/win3x/serv-u.arj/SERV-U.TXT

Text File | 1996-11-08 | 156.9 KB | 3,301 lines

                         FTP Serv-U


                FTP-Server Daemon for WinSock


                         Version 2.1







                       **************
                    The Serv-U Web site:
          All you ever wanted to know about Serv-U
                and always the latest version

                   HTTP://www.cat-soft.com
                       **************





                         Revision 1
                        November 1996
                  c 1995, 1996 Rob Beckers
                          Cat Soft





                         DISCLAIMER
                         ==========

I  know, it's not the nicest way to start off. So let's  just
get this part over with, OK?!

The  FTP  server  program Serv-U and  its  documentation  are
copyright Rob Beckers. It is distributed as shareware, giving
you  the  right  to try it for a period of 30  days.  If  you
intend  to  use Serv-U after the initial try-out period,  you
are obliged to pay the registration fee.

The next paragraph is a beautiful piece of prose. In just two
sentences it says it all. Alas, with all the sue-happy people
in  this world it is unfortunately necessary, so please  bear
with me.

This software is provided by the regents and contributors 'as
is' and any express or implied warranties, including, but not
limited  to,  the  implied warranties of merchantability  and
fitness for a particular purpose are disclaimed.  In no event
shall  the regents or contributors be liable for any  direct,
indirect,  incidental, special, exemplary,  or  consequential
damages  (including,  but  not  limited  to,  procurement  of
substitute goods or services; loss of use, data, or  profits;
or business interruption) however caused and on any theory of
liability,  whether  in contract, strict liability,  or  tort
(including negligence or otherwise) arising in any way out of
the  use of this software, even if advised of the possibility
of such damage.
Contents


TABLE OF CONTENTS
=================

Introduction                                               1

1. Making It Work - Installation                           3
  1.1 Installation                                         3
  1.2 Network  Installation                                4
  1.3 Command Line Options                                 4
  1.4 Quick Setup                                          4
  1.5 De-installation                                      5
  1.6 Upgrading                                            5
  1.6 Known Bugs & Problems                                6
  1.7 A Word to the Wise (but paranoid)                    8

2. Using Serv-U - How To .                                 9
  2.1 How to Setup Your Server                             9
  2.2 How to Add a User                                   10
  2.3 How to Change a User                                13
  2.4 How to Use Access Rules                             14
  2.5 How to Setup Anonymous Access                       16
  2.6 How to Use Groups                                   18
  2.7 How to See Who is Logged In                         19
  2.8 How to Kick a User Off the Server                   20
  2.9 How to Setup Logging                                20
  2.10 How to Use Sign-on and/or Sign-off Messages        21
  2.11 How to Setup User Specific Login Messages          22
  2.12 How to Use Directory Change Messages               23
  2.13 How to Use Links à la UNIX                         24
  2.14 How to Set Up Upload/Download Ratios               25
  2.15 How to Limit Disk Usage of Users                   26
  2.16 How to Limit Access by IP Number                   26
  2.17 How to Print via FTP                               28
  2.18 How to Execute Programs via FTP with Serv-U        28
  2.19 How to Use Serv-U with 'SLIP/PPP Emulators'        29
  2.20 How to use Netscape to access Serv-U               30
  2.21 How to Let the Whole World into Your Server
       (and Delete All Your Files)                        30
  2.22 How to use multi-homed IP support                  31

3. The Inner Workings                                     32
  3.1 Serv-U Internals                                    32
  3.2 The SERV-U.INI File                                 33
  3.3 Using External User Access Verification DLLs        40

4. Getting In Touch - Bugs & Registration                 45
  4.1 Serv-U Mailing List                                 45
  4.2 Reporting Bugs                                      46
  4.3 Registering Serv-U                                  46
  4.4 Registration in the US                              47
  4.5 Registration from Abroad                            47

Registration Form Serv-U                                  49


INTRODUCTION
============

Thank you for giving this program a try!

With  Serv-U, your PC will be turned into a FTP server.  This
means  that  others  on  the computer network  that  you  are
connected to (Internet for most people) can access your PC to
copy, move, make, and delete files and directories, using the
FTP  protocol  (FTP = File Transfer Protocol). This  protocol
dictates standard ways of communication between computers, so
that  many  different  types  of computers,  using  different
operating systems and file formats, can exchange files.

Serv-U  is  a  'server' program, also called a 'daemon'.  The
term  daemon comes from ancient Greek mythology.  There,  the
Daemons  were  half-gods, acting as  messengers  between  the
people on earth and the gods. This FTP server acts, likewise,
as a messenger for file transfer between FTP clients and your
computer. Once started it sits in the background waiting  for
a   client  to  contact  it  and  after  communications   are
established, acting out the client's commands.

There  are  FTP  servers  (and clients)  for  many  different
systems. This particular program is meant for PC's running MS-
Windows  that  have  a WinSock version 1.1 compatible  TCP/IP
stack installed.

Why  use  this  program and not one of  the  many  other  FTP
servers that are available? For this I have to take you  back
in time a little, to a little over two years ago. I needed  a
FTP  server to make some files available to others and  tried
out  a  number  of server programs. One simply  didn't  work.
Another   would   work,  but  as  soon  as  someone   started
transferring  a file from my PC it would lock  up  the  whole
machine  until the transfer was complete. And then there  was
one  that  worked  fine, but lacked all but  the  most  basic
security. So, after endless frustration I decided to write my
own, figuring it couldn't be that hard. As usual things got a
bit  out  of  hand, but after a year and 11000 lines  of  C++
there  was version 1.0. The current version, v2.1,  was  made
two and a half years later, and consists of  over 22000 lines
of code. I hope you like the result!

So what has this FTP server to offer?

     * Available  in 16- and 32-bit versions for  Win3.1,
       WFW3.11, Win95, and NT.
     * At  the time of this writing there were over  3500
       registered users of Serv-U, with many of those for multiple
       copies!
     * Access for multiple clients at the same time. Access for
       'Anonymous' users. With the possibility to limit the number
       of clients at any given time, so your PC remains workable.
     * Lots of security! On a directory and even file basis.
       Allowing different settings for each user, and by putting
       users into 'groups' permitting easy maintenance for large
       numbers of users. There's even an option to allow or prohibit
       clients on the basis of their IP-number. Ideal if you want to
       let certain people roam around your computer, but you don't
       want the whole world knocking at your door (that is to say:
       they can knock, but they won't get in).
     * Support for 'multi-homed IP' sites that need a single
       server for servicing several IP numbers.
     * Supports  upload/download ratios, and  disk  quota
       limitations.
     * Lots of other features, like configurable sign-on and
       sign-off messages, per user configurable login messages,
       directory change messages, and UNIX-style 'links'.
     * Serv-U lets you execute programs remotely though your
       FTP client.
     * It allows transfer to or from ports, like PRN:, LPT1:,
       COM1:, and AUX:. This allows you to setup your PC as a print
       server by simply transferring the file to be printed to the
       desired  port! Since the ports are part of the regular
       security system, a user needs permission to transfer to/from
       a port, allowing you to control who can use it.
     * A quite complete implementation of, and very strict
       adherence to the FTP standard (found in documents RFC 959 and
       RFC 1123). Supports the 'passive' command PASV. This is
       needed by WWW browsers and proxy agents (something required
       when there is a 'firewall') for FTP transfer. Another feature
       is that you can let 'Anonymous' users always see the root
       directory ('/') as their login directory. This, again, is
       needed by some WWW browsers to make FTP transfers work.
     * Support for the 'resume' command.
     * Support for external user access verification DLLs.
     * Easy to setup and maintain. Everything is accessible
       through menus, and for automated maintenance the settings are
       stored in an .INI file of simple format.
     * There is lots of logging! You can select how much to log
       and where (to screen and/or file). The logfile is of a
       standard format to make machine reading easy, in case you
       need to do that for accounting purposes.
     * It is fast! The file transfer speed you'll get will be
       very close to the maximum your TCP/IP stack is capable of
       (well, assuming your FTP client is at least as fast of
       course).
     * Life-time free updates when registered (As long as Serv-
       U exists).
     * Compared to the commercial implementations, Serv-U is
       dirt cheap: less than 0.11 per line of code!

If  you didn't register this program, then you're looking  at
the  try-out  version of Serv-U. When started for  the  first
time, it'll let you choose between a fully functional program
or  a  somewhat  crippled one. The text during  startup  will
explain  these  options  clearly. If  you  choose  the  fully
functional  version  then there is absolutely  no  difference
with  the  registered version. But (yes, there had  to  be  a
'but'),  after  a little over 30 days it will  stop  working.
Counting  starts the first time you run the program.  I  warn
you beforehand: re-installing it will not help you!

And  finally: A big 'Thanks' to all the beta testers of Serv-
U.  The  list  is  now  so long it is no longer  possible  to
mention each one individually, but you guys definitely helped
to  make Serv-U a better product! Any bugs that remain are of
course  my  own fault. Special thanks to Ryan and Kevin,  for
revising  the  manual! And, Alun, sorry again!  Seems  you'll
have  some catching up to do (The monopoly is now really gone
I fear).

OK,  enough  sales  talk.  Let's  continue  with  the  actual
documentation. First thing will be how to install  Serv-U  to
get you in business.


1. MAKING IT WORK - INSTALLATION
================================

You're eager to get things going, but a little afraid of what
lies ahead. Never fear, it couldn't be simpler. So let's  get
started!

1.1 Installation
----------------
Nothing is simpler than installing Serv-U: just unzip  it  in
the directory of your choice and run it. There is no need  to
change your 'PATH' or put anything in other directories.

The Serv-U zip-file comes with the following files:
     SERV-U16.EXE    - The 16-bit version of the  FTP-server
                       executable itself
      - and/or -
     SERV-U32.EXE    - The 32-bit version of the  FTP-server
                       executable
     SERV-U.DOC      - The  documentation  in  MS-Word
                       version 6.0 format
     SERV-U.TXT      - The documentation in ASCII format
     README.TXT      - Something you have to read
     REGISTER.TXT    - A registration form in ASCII format
     VERSION.TXT     - A list of changes between the  various
                       versions.
     FILE_ID.DIZ     - Short description file for use by
                       bulletin boards

When  Serv-U  is started for the first time, it  creates  the
file:
     SERV-U.INI      - File containing all settings  and
                       user information

The 16-bit version of Serv-U uses Microsoft's 3D-controls  to
make the dialog boxes look better. If for some reason you get
flat-looking dialog boxes it means that the file  CTL3DV2.DLL
is  missing.  This  file should be in your Window's  'system'
directory.  It  is rare if this file is missing,  since  just
about  anything these days uses it. However, if  you  need  a
copy then drop me a line. The 32-bit version uses Windows  95
style  controls. This means things will look flat on NT 3.51,
this  is  normal. In NT 4.0 and Win95 you will  automagically
get the 3D-look.

Serv-U offers two very distinct ways to try it out. Each with
its  own  advantages and disadvantages. When started for  the
first time (or in absence of a SERV-U.INI file), it will show
you  a screen explaining the two try-out options and allowing
you  to  choose  one  of them. The first choice  is  a  fully
functional  try-out version exactly equal to the real  thing,
but it will stop working after 30 and some days. It does this
by  contacting  a permission server over the  Internet  every
time Serv-U is started. The permission server keeps track  of
when the program was started for the first time and uses that
information  to  determine if it should  be  allowed  to  run
again,  or not. It then sends this answer back to Serv-U  and
the program will consequently work or stop. To this effect, a
network packet is sent to the permission server containing  a
version  code, the IP number of your PC, ID, and a  run/norun
flag.  It receives back the same packet with the flag set  to
run  or  stop. This is all that is communicated  between  the
systems, nothing more, nothing less!

The  second  choice  is a try-out version  that  is  somewhat
crippled. It will only allow a total of 10 file transfers  (5
PUTs  and  5 GETs), it will show a message saying it  is  not
registered  to anyone who logs into the server, and  finally,
it  will  only stay on-line for one hour. You have to restart
it  again  after that to get another hour. The  advantage  is
that  it  will  not  contact my permission  server  over  the
network.

Just to make sure this is clear: Once Serv-U is registered it
will NEVER send anything over the network other than what  is
needed  for  regular  FTP traffic! In short:  The  registered
program will NOT contact my permission server!

1.2 Network  Installation
-------------------------
To  find  the  setup information, Serv-U first looks  in  the
program directory (i.e. where SERV-U.EXE is located) for  the
file  SERV-U.INI. If no .INI file is found, the program looks
for  the  existence of an environment variable with the  name
SERV-U. If this variable exists, it should be set to the path
for  SERV-U.INI. The program will then use the .INI file this
path  points  to.  For network use with a  single  executable
shared  between many users that need their own settings  this
is  a  convenient  way to set things up. If this  environment
variable  does  not  exist, the whole DOS  path  is  searched
including  the  Windows directories. If a file SERV-U.INI  is
found somewhere it will be used, this way also allowing for a
single  copy  of  the  executable on a network  server  while
having  individual settings for each user. Finally, if  SERV-
U.INI  was still not found, it will be created in the default
program directory.

If  a  SERV-U.INI file is available it does not  have  to  be
writable  per se. The program will work when it is read-only,
but  setup  changes and the current position  of  the  Serv-U
window will not be saved.

1.3 Command Line Options
------------------------
Serv-U  recognizes a number of command line options that  may
be  convenient  to  tailor  it to your  particular  use.  The
following is recognized:

     / h  = Hide the server after startup.
     / i  = Start the server as an icon.
     / u  = Stop 'unconditionally'.

Hiding  the server makes it disappear, there will be no  icon
nor window and no way to interact with it. All you can do  to
stop  the  server after that is either kill the task  in  the
task  manager,  or  reset the computer.  The  'unconditional'
option means that if the server is stopped it'll quit without
any  warning, even if there are still users logged  in.  This
can  be  convenient if you want to be able to stop the server
from a script.

1.4 Quick Setup
---------------
When you run Serv-U for the first time there will be no users
and  access  will be restricted.  This section will  describe
the  bare  necessities to allow access. In addition  you  can
also  go  through  the 'Setup' menu items  and  put  in  your
heart's  desires. The next chapter will explain  the  various
options and how to use them. You might want to take a look at
it,  since  the  setup  is simple but not  totally  intuitive
(Sorry for that, I tried hard but . . .).

Now, to quickly get Serv-U up & running, just start it. Leave
all  the settings at their defaults, since in most cases that
will be OK. By design Serv-U was made to be 'safe' out of the
box:  Unless you specify otherwise your PC is well  protected
by  the default settings, giving you one thing less to  worry
about. Right! Let's have a go at it.

At  this  point you have a functioning server but no  defined
users,  so  no  one can log in. To define users,  go  to  the
'Setup  - Users' section  in the menu and you'll see a  blank
user  setup  screen. Now I'll assume you want to  setup  your
server  for  anonymous  access. To make  that  work,  do  the
following:
     * At  'User  name', type the name we  want  to  add:
       'anonymous'
     * At 'Home directory', type the directory where you want
       anonymous  users to be. Let's assume we want  them  on
       'd:\anonftp', so enter this (or press 'Browse' and choose
       your favorite home directory for anonymous users).
     * Press the 'Add' button of the 'File/Directory access
       rules' section.
     * Anonymous users need access to their home directory, so
       enter 'd:\anonftp' in the dialog box and press 'OK'.
     * To hide the rest of the PC from anonymous users we'll
       make them see '/' as their home directory. To do this select
       the 'Miscellaneous' button. In the dialog box that pops up
       check the 'Show path relative to homedir' button and press
       'OK'.
     * That's all, just leave the other settings at their
       default values and press 'Store' to save your setup.

You  now have a user with name 'Anonymous' that can log  into
the  server.  Of  course, if you want anonymous  users  in  a
different  directory then 'd:\anonftp',  then  feel  free  to
change  this. Just make sure that the directory  you  specify
actually exist and that it is part of the access rules.

If  the  zip-file you have came with both the 16- and  32-bit
version of Serv-U (SERV-U16.EXE and SERV-U32.EXE respectively
-  the  first is for Win3.1 and WFW3.11, the latter for Win95
and  NT),  and  you only need one of them, then  you  can  of
course delete the other to free up disk space.

1.5 De-installation
-------------------
It  is  hard to imagine why, but if for some reason some  day
you  want to get rid of Serv-U then that is just as  easy  as
was  installing it. Just delete the whole directory where you
put  it,  and  that's it! Serv-U does not change  any  system
files and does not place any files in other directories.

1.6 Upgrading
-------------
Upgrading from an earlier version of Serv-U is not difficult,
but  there are a few things to keep an eye on. Here  are  the
steps to follow:
     * If you are running Serv-U: Exit the program.
     * Make a backup of the old Serv-U files. Just in case.
     * Unzip the new Serv-U zip-file in a temporary directory
       and copy the contents over the existing files in your Serv-U
       directory (Watch out that you get the direction of copying
       right!).
     * Go to the Serv-U directory and delete the file BWCC.DLL
       if it exists, version 2 no longer needs this file. Note: Only
       delete BWCC.DLL if it is in the Serv-U directory, do not
       delete the one in the Windows\System directory as other
       programs might use this.
     * If you are using '%' directives in signon and signoff
       messages, login messages or directory change message, then
       you might have to change those. The directives of version 2.0
       no longer work and some of the directives of 2.0c have been
       changed. Take a look at the 'How to setup sign-on and/or sign-
       off messages' section for the new directives.

Your  old SERV-U.INI file will be used by the new program  so
you  don't  have to re-install any users. All your  settings,
and your registration key (which also resides in SERV-U.INI -
in case you registered), stay intact.

The 16-bit version of Serv-U now uses Microsoft's 3D-controls
to create a 3D-look. This is done by a file named CTL3DV2.DLL
which should be in your WINDOWS\SYSTEM directory. Most likely
you  already have this file, and therefore it is not part  of
the  Serv-U zip-file. But if the dialog boxes look flat  then
drop  me a line and I will make the DLL available. Note  that
this is only meant for the 16-bit version of Serv-U. The  32-
bit  version will always look flat on NT 3.51! On Windows  95
and  NT  4  the  32-bit  version will use  the  built-in  3D-
controls, and thus have a 3D-look.

1.6 Known Bugs & Problems
-------------------------
At  the  time  this documentation is being written  the  only
known  bug  left in the program is the lack of on-line  help.
Everything that was found in earlier versions has been fixed.
If  you  have  any  problems,  please  first  check  out  the
'Frequently  Asked Questions' on my Web site (HTTP://www.cat-
soft.com).  I will do my best to keep an up-to-date  list  of
everything worthwhile there.

Unfortunately  there  are still a number  of  WinSock  socket
stacks that are not 100% compliant with the WinSock standard.
Since  Serv-U uses the stack to its fullest, this can  result
in  a  number  of symptoms. The following has been  observed:
directory listings and file transfers do not work; after  the
first  client  the  server seems blocked; WWW  browsers  seem
unable to work with Serv-U; the PC is blocked when Serv-U  is
transferring a file.

Problem WinSock socket stacks
-----------------------------
Below is the current list of socket stacks that are known  to
cause  problems.  If you find any others  with  problems,  or
solutions to the ones mentioned below, please let me know  so
I can pass the word on to others.
     * The SuperTCP socket stack results in crashes of Serv-U.
       Both versions 4.00 and 4.04 were tested with similar lack of
       results.
     * Reports indicate that the WinSock stack which comes with
       an AOL account does not work. So far it is unclear if this is
       an incidental or general problem.
     * FTP Software Inc's socket stack: Their earlier stacks
       cause problems. Version 2.2 with WINSOCK.DLL v1.15.1 is
       rumored      to      work      OK.      Check      out
       ftp://ftp.ftp.com/support/ftpsoft/winsock for updates. Their
       latest version WINSOCK.DLL can be found in WINSOCK.EXE
       (currently v1.17.1).
     * Spry's Internet-in-a-box stack: Version 2.0 is rumored
       to work OK. Earlier versions had a multitude of problems.
       Check                                              out
       http://www.spry.com:80/products/upgradingibox.html for
       updates.
     * The Air socket stack is rumored to come from the same
       factory as Spry's. Won't work though.
     * Core Systems' Internet-Connect stack does not work with
       Serv-U.
     * DEC's PathWorks stack does not work either.
     * Neither does CISCO's socket stack that comes with Suite
       100.
     * Sun's PC-NFS stack version 5.1A and later works, but
       earlier versions are a problem.
     * Earlier versions of the Microsoft Wolverine stack had a
       tendency to bomb back to DOS when the network got busy. This
       has  been  fixed  in  version  3.11b,  available  from
       ftp://ftp.microsoft.com/bussys/clients/wfw/tcp32b.exe. A
       highly recommended stack!
     * Novell's LanWorkplace stack seems to work for some
       people, but doesn't for others. In any event, you need
       version 4.2T3 or later. The 'T3' patch is available from
       http://netwire.novell.com/servsup/binhtml/1203536.htm.
     * In case you have Netmanage's Chameleon's Sampler you
       need at least version 3.11. Reports are that it works fine on
       version 4.5.1 of Chameleon.
     * PC/TCP's OnNet stack locks up the PC during file
       transfers, but it works fine otherwise.
     * CompuServe's WinSock stack does not work with Serv-U
       (Wasn't that bought from Spry?!).
     * The  various  versions of Trumpet's WinSock  stack
       generally work fine. But, version 2.0b had a tendency to kill
       the socket Serv-U uses to listen for incoming clients, thus
       making the server unreachable. This has been fixed in version
       2.1f,     so     better    get    that    one     from
       ftp://jazz.trumpet.com.au/pub/winsock/twsk21f.zip.
     * Quarterdeck's socket stack does not work with Serv-U.
     * The Windows 95 built-in 16-bit TCP/IP stack usually
       works fine, and is very stable. But, it sometimes kills Serv-
       U's listening socket, resulting in 'Connection denied'
       messages  from clients. This is a Win95 bug  which  MS
       acknowledges and claims to be the result of programs not
       freeing their sockets before terminating. The latter is
       probably BS, IMHO, but it lets them pass the buck. Most
       people will never see this while others seem to have the
       problem continuously. The advise is to use the 32-bit version
       of Serv-U on Win95.

'SLIP/PPP emulators - TIA, TWinsock, Pipeline'
----------------------------------------------
If  you  are  using  a  so called 'SLIP emulator'  like  TIA,
TWinsock,  or Pipeline, there are also a number of things  to
keep   in   mind.  These  emulators  are  not  real  Internet
connections,  and because of the way they have  to  do  their
work they have a number of peculiarities. Since the PC has to
share  the  IP number with the host system you will generally
not  be  able to use the default port 21 for Serv-U. Instead,
you  either  have to use a high port number (generally  above
8000) or set up 'port redirection'. Ask you Internet provider
for  details about the latter. A related problem is that  the
IP  number  displayed by Serv-U is not  the  IP  number  that
clients  should use to contact your server. It  is  merely  a
dummy  to  keep  the socket stack of the PC  happy.  For  the
outside  world the IP number of your server is  the  same  as
that  of the emulator host system, i.e. that of your Internet
provider. Another special effect is that clients will not  be
able  to  use 'passive' mode for data transfers.  This  means
that  regular FTP clients will work OK, but WWW browsers like
Netscape and Mosaic will not work when Serv-U runs via a SLIP
emulator.  For  the same reason it won't be possible  to  use
clients that are also connected via a SLIP emulator.

Dynamic IP
----------
If  you  use a modem and telephone to connect to the Internet
via a service provider, then chances are that you will get  a
different IP number each time you connect to the network. You
can  see  what  your current IP number is by looking  at  the
startup  messages  of  Serv-U: one of the  lines  is  the  IP
number. Serv-U does not have a problem with dynamic IP.  Just
make  sure  you  start the server after  connecting  to  your
service  provider,  so  Serv-U will  report  the  current  IP
number.  However, if you want to run a steady FTP site,  then
dynamic  IP  is a pain in the lower rear end! You users  will
have  to  know  which IP number to contact and  if  yours  is
changing all the time it does not help.

Your  IP number is entirely up to your provider and there  is
absolutely nothing Serv-U can do about it! It merely uses the
number  available.  So,  if you want a  fixed  ('static')  IP
number  the  only person to talk to is your Internet  service
provider. Sometimes it is possible to get a fixed symbolic IP
name, even though the number varies each time (An IP name  is
something like 'www.cat-soft.com', you can use it instead  of
an IP number). Again, talk to your provider.

1.7 A Word to the Wise (but paranoid)
-------------------------------------
Many  a  word has been spent on the alt.winsock newsgroup  on
the  try-out enforcement practice of Serv-U, and in a broader
sense on the security of network programs. If you choose  for
the 'fully functional try-out version' then this program will
communicate with a remote system to determine if it should be
allowed  to work or not. That is the way the 30 days of  try-
out  are  enforced. To that effect, information is  exchanged
between your PC and a server over here, and as people  asked:
How  do I know that my password file is not being sent  over?
Another, but similar question is: How can I be sure there are
no  'back doors' in the server, allowing access to the author
at any time? The short and hard answer is: You don't know and
you can never be sure!

I  know this is not much of a deal, so I'll at least give you
one option to establish my good intentions. To anyone who  is
interested,  I  offer to personally go over the  source  code
with you (all 22000+ lines of it) and we'll compile it on the
spot. You will understand that I am not going to hand out any
source  code. If you want to take it home you'd better  bring
along a whole lot of $$$'s!

It  is worthwhile to realize that security is a problem  with
any  type  of  network  program. It  is  fairly  easy  for  a
programmer  to put code in, for example, a WWW  browser  that
will  wait  for  5  months, until the  full  moon  and  Venus
coincide, then monitor PC activity and if a user hasn't  been
present for a few hours, or if it's 4 in the morning,  starts
sending  over  the  whole hard disk to unknown  destinations.
This  kind  of thing is not easy to detect, don't let  anyone
tell  you  otherwise, and I still have  to  meet  the  system
manager that keeps a network monitor running 24 hours a  day,
year  after year and actually reads the log files. The bottom
line  is  that you will have to trust the author of a program
at some point, there is no other choice!

Now don't write to me that conversely I should trust you that
"the check is in the mail and please send me the registration
key in advance".

That is all I have to say about installing Serv-U. Next let's
look  into how we can use it to get some real work done.  The
next chapter will take you through all its features.


2. USING SERV-U - HOW TO ...
============================

Rather than describing every menu and dialog box to its  last
boring detail, I though it would be more useful to present  a
task-driven approach. This chapter is therefore divided  into
sections that each describe how a specific task can be  done,
in the form of 'How to' questions and answers. There is a bit
of overlap between the sections, so you might come across the
same  thing more than once. If you read this manual cover-to-
cover  then you will also have learned about every  menu  and
dialog  box  detail  in  the process.  Makes  great  bed-time
reading!

2.1 How to Setup Your Server
----------------------------
You  shouldn't believe all I say: This first section is going
to  go  over  the 'Setup - FTP Server' menu choice  in  every
grueling  detail! No, seriously, this dialog  box  stands  so
much  at  the  basis of Serv-U's operation and the  items  in
there  do not fit very well in other sections, that it  is  a
good  idea  to cover it first, and I will only discuss  those
items that are not covered by other sections. So, let's  pull
up the 'Setup FTP-Server' dialog box.

The first item is 'FTP port number'. This is the (you guessed
it!)  port number that the server will listen on for incoming
FTP  clients.  The default is number 21, but you're  free  to
fill in anything you want, provided it does not conflict with
other  network programs. Filling in a number that is  already
in  use will make Serv-U complain bitterly, so that's easy to
catch.  Of course, the rest of the world expects a FTP server
to  listen  on port 21, but changing it to another number  is
one  great  way  of insuring that only you and some  selected
friends will know about your server.

The  next  item is the 'Maximum no. of users'. With this  you
set  the  maximum number of simultaneous users at  any  given
moment.  Setting  it  to 0 will not allow  anyone  to  enter,
leaving  it  blank will allow an unlimited number,  or,  more
precisely, until the PC runs out of network sockets or  other
resources  like memory. If you need your PC for regular  work
as  well as being a FTP server, it is probably wise to set  a
maximum so normal operations will not be slowed down too much
by  clients. Likewise, 'Maximum no. of anonymous' limits  the
number  of 'Anonymous' users at any given moment. If 'Maximum
no.  of  users' is specified, then this will limit the  total
number of users, both regular and anonymous, even if 'Maximum
number of anonymous' is set to a larger number.

Some people have asked what would be reasonable settings  for
the  maximum number of users that would still keep the system
workable. The answer is: It depends. It depends very much  on
whether these users are local and thus capable of using up  a
large  bandwidth in data transfer, or alternatively, if these
users  are  further  away  on the  Internet  and  cannot  get
transfer  speeds  of  more than about 10 Kbytes  per  second.
Another  concern  is  the socket stack. Some  WinSock  stacks
start  behaving erratically when they have to  service  large
numbers  of  sockets. Most notoriously is or  was  the  first
version of the Microsoft 32-bit 'Wolverine' stack, which  had
the  tendency to kick the system back to MS-DOS  without  any
warning  when  heavily loaded. One way to find out  how  many
users  your system can handle, in case you run Windows 95  or
NT, is to start the system monitor and keep an eye on the CPU
usage percentage. This will give you a pretty good idea  very
fast.  My experience is that even a measly 486 can handle  20
or so concurrent users with easy.

This  brings  me  to another topic which is  related  to  the
above:  Server stability is going to depend very much on  the
operating  system you are using. MS-Windows 3.1  and  WFW3.11
are  inherently so unstable that you should not expect Serv-U
to  run for more than a few days at a time before a reboot is
needed. Very much better is Windows 95, especially when  used
with  the  build-in socket stack. Having used  it  since  the
early  betas  it seems to work fine for several  weeks  at  a
time. Definitely recommended for serious server work! At  the
top  of  the stability list stands NT. The Cat Soft ftp  site
(ftp.cat-soft.com) has been running on NT for quite  a  while
now, and it seems very stable!

Another often asked question concerns maximum transfer speeds
that can be obtained with Serv-U: Let's just say that even on
a  measly  486 you don't have to worry about this unless  you
have  at  least  a T3 network connection, Serv-U  can  easily
saturate  a T1 line (= about 1.5 Mbits per second).  You  can
try  out raw speed by yourself: Just start a FTP client, like
WS_FTP  on  the  same PC as where the server is  running  and
transfer some files through it. This bypasses the network, so
what  you are seeing is Serv-U plus hard disk access and part
of  the  socket stack. The conclusion from this will probably
be  that your biggest performance bottle neck is going to  be
your network connection.

Let's  get on with the list. To  make sure that users  cannot
log onto your server and keep connections open until eternity
it   is  possible  to  set  'Time-out  users'  and  'Time-out
anonymous'. If a connection has been idle for more  than  the
number  of  minutes you specify here it will be automatically
closed.  Filling  in 0 or leaving it blank switches  off  the
time-out.  It  is  a good idea to fill in some  values  here,
since  otherwise the system would slowly fill up with sockets
that  for  some reason got stuck, not to mention  users  that
connect  and  start  a transfer just before  they  leave  the
office in the evening and then go home. Default values are 15
minutes  for anonymous users and 10 hours (=600 minutes)  for
regular users.

If  you would like to leave your PC wide open for the rest of
the world you can uncheck the 'Enable security' checkbox. But
beware:  DISABLING SECURITY WILL ALLOW ANYBODY ON THE NETWORK
TO  DELETE/CHANGE/COPY  EVERYTHING ON  YOUR  PC!!!  The  only
reason  I  put this option in is to make it easy  for  people
that have their own local network and don't want to mess with
users  and  passwords. By default this option is, of  course,
checked.  DO  NOT  EVER  LEAVE THE 'Enable  Security'  OPTION
UNCHECKED IF YOUR PC IS CONNECTED TO THE INTERNET!!!

The  rest  of  the items in the server setup dialog  box  are
covered  in other sections of this chapter. So, just read  on
and you'll eventually get to know them all.

2.2 How to Add a User
---------------------
One of the most fundamental tasks you are going to have to do
is  adding  new users. Unless you switched off all  security,
you are going to have to deal with this.

Upon choosing the 'Setup - Users' menu option a dialog box is
presented  to you. It contains a list of all known  users  on
the  left and by clicking on one of those users you  can  see
the  settings for that user on the right side.  Now,  if  you
just started this server for the first time there will be  no
names  in the list, short of Divine Intervention. If you  are
at this point and are about to setup your first user, just go
ahead  and  type in the various fields. If there already  are
users defined you will see the settings of the first one  and
to  get  rid  of  this and create an empty sheet  just  press
'New'.  Doing the latter will pop up a little box asking  you
for the new user's name, which I think speaks for itself.

The  next thing can come in handy, so pay attention: You  can
fill  in or change any name in the 'User name' field. If this
new  name  does  not exist it will be added to  the  list  of
users.  If this name exists, the settings for this user  will
be  changed to the ones in the dialog box. In short, this  is
another  way  to  add new users. So, if you clicked  on  user
'James' and then go on to set his password to 'lightbulb' and
you  change  the user name to something that does  not  exist
yet,  let's  say 'Tanya', then you just created  a  new  user
Tanya with all the settings of James except for his password.
This  way  of dealing with users might strike you as somewhat
strange. The advantage of it is that you can take an existing
user and, by making only the few needed changes, turn it into
a new user.

Now  let's  take a closer look at the various fields  in  the
'Setup  Users'  dialog box. I've dealt with the  'User  name'
field,  so this brings us to 'Group name'. Every user can  be
part  of a group. The convenience in making users part  of  a
group is that you can leave common settings for all users  of
a particular group blank and just fill them out in the 'Setup
Group'  dialog box, about which you can find more information
later  on  in the 'How to use groups' section. This goes  for
all  settings,  including password, home directory  and  path
access  rules.  To overrule a certain group  setting,  simply
provide  one for the user. Only exception for groups  is  the
user  with  special  name 'Anonymous'.  For  'Anonymous'  the
system ignores any group setting you might have. In fact,  if
you  try to enter a group for a user with that name it  won't
even  get  stored and is gone the next time you look  at  the
settings for 'Anonymous'. This was done for security reasons.

We  did  get  ahead  of ourselves in the  discussion  of  the
various fields, so let me back up a bit. The 'Password' field
is  of course for adding a password for a user. The passwords
are stored encrypted using UNIX 'crypt'. As is normal for the
'crypt' function, only the first 8 characters of the password
are used. Don't loose any sleep over this though, it is still
very  safe. This algorithm works like a sausage machine:  you
put  in  a  pig on one end and turn the crank, out comes  the
sausage. But, pushing in the sausage while turning the  crank
backwards  will  not  get you a pig! It is  quite  secure,  I
wouldn't  know  of a way to get the plain text password  back
(the  NSA  might though). Once a password is stored you  will
only see the word '<<Encrypted>>' in the password field. This
is  to indicate there is a password. You cannot edit existing
passwords,  since  the original is truly lost  and  only  the
encrypted  form  is kept. The only way to  change  it  is  by
typing in a completely new one.

If you leave the password field empty this does not mean that
the  user has no password. Serv-U assumes that all users need
a  password and will try if there is a group setting and look
at  that  for the password. If no password can be found  then
access will be denied to the user. There is a way to setup  a
user without a password, but  it needs direct editing of  the
SERV-U.INI  file. You can find the details in the chapter  on
Serv-U internals.

There  is  one  more  exception  with  passwords  that  you'd
probably already know: The user name 'Anonymous' never has  a
password. Instead, Serv-U will ask for a E-mail address.

The  'Home  directory' field is for the user's home directory
(To  kick in an open door). This is the place where he or she
is  put immediately after logging in. Each user needs a  home
directory, without one the server will not permit logging in!
Of course, if a user is part of a group, and this group has a
home  directory you don't have to specify one here. You might
want to, if this user needs a different one from the rest  of
the  group.  Home  directories always need to  be  full  path
names, including a drive letter!

A large portion of the 'Setup Users' dialog box is devoted to
'access   rules'.   These  determine  to  which   files   and
directories a user has access. In general, you will  have  to
make  sure that the user has at least read access to  his  or
her  home directory. The quick-and-dirty way to setup  access
for a user is therefore to press 'Add' and enter the path  of
the  user's home directory. Then check the appropriate access
rights, which in this case should be at least 'read', 'list',
and  'inherit',  and you have a functional account.  Although
their use is pretty straight forward in most cases there  are
still  some  ins and outs to access rules. So please  take  a
look at the section 'How to use access rules' which discusses
them in more detail.

Obviously, clicking the 'Store' button will store  the  newly
created user settings. But this is not the only way: You  can
also  leave  the setup screen by pressing 'OK',  any  unsaved
changes  will  be stored as well. Also, if you  already  have
other  users set up, clicking the mouse on another user  name
will save changes.

We  already came across the special user name 'Anonymous'  to
allow  access  without a password. The  user  name  'FTP'  is
understood  by  Serv-U as a synonym for 'Anonymous'.  When  a
user  enters  'FTP' it will be translated to 'Anonymous',  so
the  latter's settings apply to 'FTP'. There is one more user
name  with  special meaning to Serv-U: 'ALL'. Now where  does
this  tie in? Well, every action requiring security clearance
(checking a password during login, reading, writing, etc.) is
first  checked against the settings for the particular  user.
If  no  appropriate  setting is found  there,  and  the  user
belongs  to  some group, the group settings are  checked.  If
still  no  corresponding setting is found, the user 'ALL'  is
consulted (if it exists). So 'ALL' works as a blanket for all
users,  providing the most common settings. Of  course,  this
also provides a potentially big security hole, so be careful!

Most  of  the other buttons and items are explained in  other
sections,   but   let's   go  over   the   details   of   the
'Miscellaneous' dialog box here. If all you want is to set up
simple  FTP access you probably can ignore anything in there.
The  miscellaneous items let you fine-tune some details  that
might  be  useful.  Just press the 'Misc' button to get  into
it.

If you want to disable the account of a user so he cannot log
in without deleting it, this is done by checking the 'Disable
account' checkbox. A tip: This also works in a group, so  you
can  disable  an  entire group of users with a  single  mouse
click!

The  next item, 'Show path relative to homedir' can  be  very
useful  and powerful, but there are some snags to it  so  pay
close attention: When this is enabled Serv-U will try to show
all the directories a user deals with as if they are relative
to  the  user's home directory (Hence the name). For example,
if  a  user has home directory c:\users\anonymous, this would
show   up   as   '/'   to  the  user.  If   he   changed   to
c:\users\anonymous\uploads all he'd  see  is  '/uploads'.  It
completely hides the real path with drive, and makes the  FTP
client believe it is in the root of the file system. This can
be great in many cases, but there are also potential problems
to it. Serv-U can only do this trick for directories that are
either  at  or  below the home directory  of  the  user.  For
example, if the homedir is c:\users\anonymous again, there is
no  way  that Serv-U can represent e:\pictures\furry relative
to  that.  In short, with 'relative paths' enabled  the  user
will  not  be able to go outside of his or her home directory
(and the directories below the homedir).

By  checking  'Hide hidden files' Serv-U will  not  show  any
files  that  have  the file attribute 'hidden'  in  directory
listings. This is useful for hiding directory change  message
files and link files.

The  final  checkbox lets you control if  a  user  should  be
allowed to log in even after the maximum number of users  has
been  reached. This is good for you yourself, as  the  system
administrator. It would let you log into your own  server  at
all times.

This  brings us to the 'Message file' field. You  can  put  a
file  name of a text file in there. The contents of this file
will  be  displayed to the user just after logging  in.  More
about this in 'How to setup user specific login messages'.

This  should  have you started in creating user account.  The
next  section  gives  you  a few details  on  how  to  change
existing user accounts.

2.3 How to Change a User
------------------------
For  the  most  part  the things mentioned  in  the  previous
section,  'How  to add a user', also apply to  changing  user
settings. However, there are a few peculiarities that deserve
extra attention.

First  of  all,  keep in mind that you can  change  a  user's
settings  at all times in the 'Setup Users' dialog box.  This
includes  the user's name, but care should be taken in  doing
this,  since there might be side effects: If you  change  the
name  to a non-existent one and store the settings this  will
in  effect  create a new user with that name.  Also,  if  you
change  the  name  to one that already exists  then  you  are
changing  the settings for the user with that name!  To  drag
our  favorite example once more out of the closet: Let's  say
you  want  to  change the password of user  'James'.  So  you
clicked  on  'James' and then go on to set  his  password  to
'lightbulb' and you change the user name to that  of  another
user,  let's  say 'Tanya'. Then Tanya is going to  be  mighty
upset when she tries to enter your FTP server! James will  of
course  have  to  remember  his old password,  since  nothing
changed for him.

Another peculiarity that can come in handy is when changes to
user  settings get stored. There are several ways to do this.
Obviously clicking on 'Store' will do the trick. Another  way
is to press 'OK' and leave the user setup. This will save any
changes  too. The third and last way to store changes  is  by
simply  selecting another user from the list on the  left  of
the  'Setup Users' dialog box. Up until you store changes you
can  recover  the  original  settings  by  the  pressing  the
'Restore' button. This does not hold for the 'Delete' button.
Pressing  this  will erase the selected user  completely  and
there is no way to get it back (I'm a nice guy, so you'll get
warned first when attempting this)!

If  you're  editing an existing user who has a password,  the
word  '<<Encrypted>>' will be shown in  the  password  field.
This  indicates there is a password, as opposed to not having
a  password in which case this can be supplied by  the  group
settings.  There is no way to recover the original  password,
once  entered it is lost! So, there is no possibility to edit
the  existing  password, you can only enter a completely  new
one.  To  do  this, erase the word '<<Encrypted>>' completely
and type in the new password.

Something that might be of interest to you if you edit  users
by  directly changing the SERV-U.INI file using your favorite
text editor (for example 'notepad'): Any changes you make  to
users  take immediate effect. No restarting of the server  is
needed.  This means that you could keep a local copy of  your
INI  file and use a local version of Serv-U to edit it.  Then
just  use  Serv-U itself for uploading the changed SERV-U.INI
file to the production site and you are all set.

That  concludes all you need to know for keeping your  user's
settings  up-to-date, but it is time to fill in a  big  blank
that is of the essence to using Serv-U: The access rules.

2.4 How to Use Access Rules
---------------------------
The 'Access rules' part in the 'Setup Users' dialog box forms
the  corner stone of Serv-U's security. This is also the part
that  makes  Serv-U unique: It allows very fine control  over
what   a  user  can or cannot do. It allows  you  to  specify
access per directory and even per file for each user!

How  does  all  this work? Take a look at the 'File/Directory
access rules' list in the 'Setup Users' dialog box. This list
contains a number of paths with access information coupled to
each  path.  Access  to the PC is only allowed  according  to
these paths and their access information. No access path,  no
access! So, there is one path you might always want to put in
the  list: The user's home directory. The check boxes at  the
right of the path list show what kind of access the user  has
to  the path in the list. Again, unless the type of access is
specified in these check boxes the user won't get in.

Let's  take  a  look at the different type of access  we  can
specify  per  directory or file. There  are  eight  different
types  of access information that can be set, four that apply
to  files,  three for directories, and the  final  one  is  a
special case. To start with file access:
     * 'Read'  access, allows files to be copied from  the  PC
       using the FTP 'get' command.
     * 'Write'  access, allows files to be copied  to  the  PC
       using 'put', but not changed, deleted, or renamed.
     * 'Delete' access, allows the user to change  files,
       rename, or delete them. Having 'Delete' access automatically
       includes write access (although it does no harm to specify
       both).
     * 'Execute' access, is meant for executing files through
       FTP, i.e. for running DOS and Windows programs remotely.

Then there are three items that deal with directories:
     * 'List' access, allows the user to retrieve a directory
       listing using the FTP 'dir' command.
     * 'Make' access lets the user create new directories at
       this path, i.e. the user can make subdirectories.
     * 'Remove' allows the user to delete directories.

The final item is somewhat special:
     * 'Inherit' means that the access rule automatically
       applies to all subdirectories of the path, i.e. the rule is
       inherited by subdirectories.

Most  of  the above should be no surprise to you,  but  let's
take  a  closer look at a few of the less clear items. First,
to  allow  a user to use the FTP command 'cd' to get  into  a
directory  any of the rights is sufficient. So, a  user  that
has 'read', 'write', 'delete', 'execute', 'list', 'make',  or
'remove'  can  change to the directory in  the  access  path.
Conversely, if a path is specified without any access  rights
(except maybe for 'Inherit') then the user has no access what-
so-ever to this path.

A  user has 'write' access to a file or path, but no 'delete'
access, can upload files to the server as long as they do not
exist  already. This is good for an upload directory, because
it  allows  uploads without the chance of changing previously
uploaded files.

'Execute' access is meant for remotely starting programs  and
usually  applies  to specific files. Be careful  in  granting
this right: For example, allowing a user to start COMMAND.COM
also  means that this user can delete anything on  your  hard
disk! More on using this in the 'How to execute programs  via
FTP with Serv-U' section.

If  you want a user to be able to see a directory listing you
need  to  specify 'list' access. This is often  used  in  the
opposite  way: For example for an upload directory you  would
want  a  user  to be able to upload files, but  not  see  and
certainly  not download anything that is already there.  This
could  be  done  by  only specifying the 'write'  right,  and
leaving 'list' access unchecked.

A  somewhat strange attribute in the list is 'inherit'.  This
does  not  so much say anything about access for a path,  but
how that access rule works for subdirectories. When 'inherit'
is  checked  the  rule will automatically be  valid  for  all
subdirectories  of  the  path  in  the  rule,  as  if   these
subdirectories  inherit  the access  rule.  This  is  usually
convenient, it means that with a single access rule  you  can
control access to a whole branch in the directory tree. Also,
if a user is allowed to create subdirectories, they will have
the same access rights as the parent if 'inherit' is checked.
In short, you are going to want to leave 'inherit' checked in
most  cases,  but sometimes it can be convenient  to  specify
access  for  a  single directory in a tree without  affecting
subdirectories  and that's when unchecking  it  can  come  in
handy.

When  a  user  executes an FTP command  concerning  files  or
directories, the user's access path list is checked to see if
the  command should be allowed to proceed. Now pay very close
attention, this is the part of Serv-U that seems  to  be  the
least  understood: The list is evaluated from top to  bottom,
and  evaluation stops as soon as an applicable rule is found.
'Applicable' means that if it is a file the user wants to  do
something with, then the file name must appear in the  access
path  list, or the directory of the file must be in the list,
or  finally, a parent directory of the file must  be  in  the
path  list  with 'inherit' checked. Directory access  uses  a
similar mechanism. It follows from this that THE ORDER OF THE
PATH ACCESS RULES IS IMPORTANT!!! Unless the access rules are
in the right order you will not get the result you want!

Since  one  example  can say more than a thousand  words,  or
something  along  that  line, let's work  through  a  typical
situation. Assume you want to setup an 'Anonymous' FTP  site.
This  needs a directory tree with all the goodies  the  users
might want to download, for which they need read access.  You
also  need  an  upload directory where users can  upload  new
goodies,  but you don't want others to be able to immediately
get  their greedy fingers on it, since you want to check  for
viruses first. So, this upload directory needs write  but  no
read  access. We decide to put everything on the big  network
drive,  'Y:', under the 'ANONFTP' directory. We  also  create
the  'UPLOAD' directory here for uploads. In Serv-U we  would
create  the  user 'Anonymous' with the following access  path
rules (and in this order):

     Y:\ANONFTP\UPLOAD     - write, inherit rights
     Y:\ANONFTP            - read, list, inherit rights

Reversing the rules will not work: If a user tries  to  write
to  the  upload directory, the security mechanism will  check
against   Y:\ANONFTP   and  conclude   that   UPLOAD   is   a
subdirectory, so the rule applies, and the rule  grants  only
read and list access. Please take note that write access does
not  allow  a user to get a directory listing of  the  UPLOAD
directory,  so  not  only won't a user be  able  to  download
anything from there, the user cannot even see what files  are
uploaded.

If  the drive letter is left out of a path, it applies to all
drives. So, a fast way to get full access to all files on all
drives is:

      \                    - read, write, delete, list, make,
                             remove, and inherit rights

Now, the same mechanism that determines access to directories
also  applies  to  files. It is possible to grant  access  to
specific  files on a per-file basis. Let's take the  previous
example about the anonymous FTP server. We want to put a file
'SECRET.TXT' in the ANONFTP directory, but nobody is  allowed
to  read  it of course. So, our access paths list would  look
like this:

     Y:\ANONFTP\SECRET.TXT - no rights
     Y:\ANONFTP\UPLOAD     - write, inherit rights
     Y:\ANONFTP            - read, list, inherit rights

Again,  the  order of the paths is important!  The  directory
access   rights   do   not  have  any  meaning   for   files.
Alternatively,  if SECRET.TXT was a directory  instead  of  a
file,  the above settings would keep users completely out  of
this directory.

2.5 How to Setup Anonymous Access
---------------------------------
Since setting up anonymous access is such a common task  when
running a FTP server, I want to present a separate section on
this  subject. It is not much different from setting  up  any
other user, so this is going to be a 'follow the recipe' kind
of instruction, with the specifics for anonymous thrown in.

First,  a  tip:  If you are running Windows 95  it  might  be
worthwhile to create a new 'DriveSpace 3' volume with all the
files  you  want to make available for anonymous FTP  access.
This  not only provides you with a lot more space due to  the
compression  (which at regular FTP speeds has  no  impact  on
performance),  but also effectively isolates the  users  from
more sensitive areas like your C: drive. So, for the rest  of
this story I will assume you just created a DriveSpace volume
named 'F:'.

Let's say all the good stuff for our users is going to be  in
subdirectories of F:\ANONFTP, and we want to allow uploads of
new files to the F:\ANONFTP\UPLOAD area.

The  first task in setting up anonymous access is creating  a
user  with  this name. Thus, go ahead, pull up the  'Setup  -
Users' menu and its dialog box. Fill in the 'Username'  field
with 'Anonymous'. The 'Group name' and 'Password' fields stay
blank, since they are ignored for anonymous anyway. Now,  the
'Home  directory'  field needs to be set to F:\ANONFTP  since
that  is  the point we want the users to start when they  log
in.

We're  almost there, but the users still need access to those
directories.  So click the 'Add' button and  enter  the  path
F:\ANONFTP.  When this is done the access rights are  already
set,  since the default of 'read', 'list', and 'inherit'  are
exactly  what  we  want. Now for the upload directory:  Click
'Add'  again and fill in F:\ANONFTP\UPLOAD. Serv-U will place
this above the previously entered access rule, which is good.
However,  the access rights are not exactly what we want,  so
uncheck 'read', check 'write' and uncheck 'list'. You  should
now  have the following two access rules in the list (In this
order!):

     F:\ANONFTP\UPLOAD     - write, inherit rights
     F:\ANONFTP            - read, list, inherit rights

This  is  all we have to do in the 'Setup Users'  dialog  box
itself,  but  there  are  some things  in  the  miscellaneous
section that are useful, so press the 'Misc' button. Once  in
there, check  the 'Show path relative to homedir' button'. It
causes anonymous users to see all directories and path  names
relative to their home directory. So, if your anonymous users
have  'F:\ANONFTP' as their home directory, they will receive
back  '/'  when they inquire with the PWD command. Similarly,
every  reference they make to a file or a change of directory
is  taken  relative to this path. The main reason  it  is  in
there  is  because most WWW browsers need 'change  directory'
access  to the '/' (=root) directory to make them work.  This
way  they believe they have access to the root and are happy,
while  on a PC you don't always want to give users access  to
your  real  root directory. The disadvantage of  having  this
mechanism  is  that anonymous users are restricted  to  their
home  directory and below, nor do they have access  to  other
drives.  Sometimes you want them to be able  to  have  access
outside their home directory tree and unchecking this  option
will  allow  that. Anonymous users will then be treated  like
any  other user as far as path names are concerned  and  they
will be able to change to parallel paths and other drives  if
their  access rights permit this. The price you pay  is  that
unless  you provide some form of access to the root of  their
home directory, i.e. 'F:\' in our example, WWW browsers won't
be able to log in.

When they log in we want to let them know the especially good
things and give them instructions on how to upload, and to do
that we need a login message file. Netscape will show such  a
message  in  a  very nice way, at the top  of  the  directory
listing.  So, let's create a file named LOGANON.TXT with  the
following contents:

     Welcome %name from %IP!
     For the latest in nature's feline beauty see directory IMAGES
     You can hear them in the directory MEOW
     Please keep uploads smaller than 100 Kb and place them in UPLOADS

Since  I  can imagine that not everyone envisions  cats  when
hearing  about 'pretty pictures' please feel free  to  change
the  text  according to your wishes! The words starting  with
'%'  are directives to Serv-U which will be replaced by  real
text  when the user logs in. '%name' becomes the user's name,
and  '%IP'  either the IP number or the IP name of  the  user
(whichever  is available). There are many more '%' directives
and you can find more information about these in the 'How  to
use sign-on and/or sign-off messages' section.

Now  let's  place the file LOGANON.TXT in F:\ and thus  enter
F:\LOGANON.TXT in the 'Message file' field.

To  store  our  settings press 'OK', and in  the  user  setup
dialog box press 'Store'.

There  are a few more things that are important for anonymous
access.  They  can all be found in the 'Setup -  FTP  Server'
menu  choice. The first field of interest to us is  'Max  no.
anonymous', this determines how many anonymous users  can  be
logged in at the same time. If you leave this blank then Serv-
U will allow any number. Use your own judgment what you think
your  machine can handle. Next is 'Time-out anonymous'.  This
determines how long Serv-U will wait when anonymous users are
not  doing  anything before kicking them off the server.  The
default  of  15 minutes is a good value, still allowing  slow
transfers  and  bad  connections to work  while  keeping  the
server reasonably clean of all those Netscape users that stay
logged in after their transfer is long done. Setting the time-
out  to  0 or leaving it blank means that Serv-U won't  check
how long a user has been idle.

The last item we need to concern ourselves with for anonymous
users is the 'Check anon. passwords' option. By default  this
is  unchecked,  which  means that anonymous  users  can  type
anything  as  a  'password' to get into the server.  If  this
option is checked, then Serv-U makes sure that the 'password'
entered by anonymous users is something that looks like an E-
mail address. Netiquette prescribes that anonymous users send
their E-mail address as a password, alas this good custom  is
disappearing fast and version 2.0 of Netscape does  not  even
have  the ability to do this anymore. So, unless you want  to
severely restrict access and teach people good manners it  is
probably best to leave this unchecked.

Just  so  you  know: As is customary for FTP servers,  Serv-U
also  looks for a '-' (hyphen) as the first character of  the
anonymous  'password'. If present, all  login  and  directory
change messages are suppressed.

Well,  you made it through and now know just about everything
there  is to know about setting up anonymous access  to  your
server. You can enhance things further with sign-on and sign-
off  messages, directory change messages and links, which are
covered in the following sections.

2.6 How to Use Groups
---------------------
To ease the burden of maintaining a large site somewhat, Serv-
U  uses  the  concept of 'groups'. This allows you  to  group
together  users  with similar settings. All the  similarities
are  stored  in  the  group  information,  leaving  only  the
differences per user for you to set up.

To  edit groups select the 'Setup - Groups' menu choice.  The
dialog box you see should look familiar by now: It's the same
one  as  for the user setup. So, if you know how  to  set  up
users, you also know how to set up groups! The only item that
is not applicable for groups is the 'Username' field, so this
is  grayed  out,  instead you use the 'Group name'  field  to
specify the name of the group you are editing.

To  show  the power of groups a quick example: Let's say  you
are  the Pentagon system administrator and want to create FTP
access for everybody in case they are on field trips. So, you
hook  up  this old PC to the net, install Serv-U and register
it  (Hypothetical situation). Then you proceed  to  create  a
group 'StarWars'. Now you go on to set the password for  this
group to 'RonaldR', and their home directory (all their files
are shared anyway) to 'y:\super\secret\starwars'. You fill in
some  access path rules as well, and you're all set: The only
thing  left  is  entering the user names, you don't  have  to
provide any other information per user. A 10 minute job.

Now  there's this occasional guest user, 'BillyC'. You  don't
want  him to get into certain directories, so you make him  a
member  of the group but specify those secret directories  in
his access path rules with 'no access', and you're all done.

As  you  already  saw  from  the previous  example  the  user
settings have precedence over the group settings. This allows
you  to  selectively  override certain  parts  of  the  group
settings,  making groups a very flexible mechanism  for  user
maintenance.  To  summarize: Serv-U first checks  the  user's
settings, then looks if the user is part of a group and if so
uses  this group's settings, and finally, if nothing is found
yet  the settings of a user with name 'ALL' are used if  they
exist.  The  only  user that cannot be used together  with  a
group  is  'Anonymous'. For security reasons  only  the  user
settings themselves are used here.

Well, by now you know most of what there is to know to run  a
smooth Serv-U FTP server. The next sections are mostly  about
goodies  that make life easier or more colorful. Next  you'll
learn how to find out what users are doing on your server and
if they are nasty, how you can boot them off.

2.7 How to See Who is Logged In
-------------------------------
Even  though Big Brother might not be watching you,  you  can
certainly  watch your users! Select the 'File  -  User  Info'
menu  choice  and  up pops the user information  window.  The
upper  part shows a list of all users currently connected  to
your  server. By clicking with the mouse on one of the  users
you  can  get extra information about that user in the  lower
part of the window.

There  are  a  few  things  to keep in  mind  concerning  the
displayed  statistics: The IP name is found by  initiating  a
reverse DNS lookup of the IP number. It can take time  before
an answer comes back from the DNS server, and there are quite
a  few IP numbers that do not have an IP name. So, it is  not
at all unusual for a user not to have an IP name.
Then,  the  transfer speed displayed should not be taken  too
absolute.  Since the socket stack buffers any  send  activity
(Serv-U can write lots of bytes to the stack in a very  short
time, after which the stack sends it off at its leisure)  the
indicated speed can be much higher than it actually is. Also,
if  there are local transfers going on with a very high speed
then Serv-U and the socket stack can get into a tight loop of
sending or receiving, and the user information might not  get
updated  for  some time. This is normal ("Not a  bug,  but  a
feature!").

This  brings us to the 'Show Commands' button. Pressing  this
will  pop up another window which will show you all  the  FTP
commands  the  user  sends and the replies  from  Serv-U.  It
tracks  the commands of the in 'User Info' selected user  and
by clicking on another user you can switch.

The  last  button of interest in this window has the  prosaic
name  'Kill  User'. This is the place where, if so  inclined,
you  can  alleviate all your frustration after a particularly
bad  day  at the job. For that reason the entire next section
is devoted to it.

2.8 How to Kick a User Off the Server
-------------------------------------
If  someone is doing things you don't like, or you just  want
to be mean, Serv-U offers you the option of kicking that user
off your server and keeping him or her off.

This is done by selecting the 'File - User Info' menu choice.
In the window that pops up as a result you select the user-to-
be-killed,  and proceed by pressing the 'Kill  User'  button.
This  will  pop up a little dialog box asking you  if  you're
really sure about this, and offering several options to  keep
the user in question off on a more permanent basis.

You  will see two checkboxes. The first is 'Refuse IP  access
in  future'. If you check this and then press 'OK' the user's
IP  address will be added to the list of IP numbers that  are
refused  access. This will prevent that user from logging  in
again,  or at least it not from the same IP number.  We  will
talk  about  access and IP numbers in greater detail  in  the
'How to limit access by IP number section'.

The  second  checkbox is 'Disable account' and checking  this
does exactly that: The 'Enable' checkbox in the 'Setup Users'
dialog box will be unchecked. Nobody will be able to use that
login name until the account has been enabled again.

2.9 How to Setup Logging
------------------------
When  you  select the 'Setup - Logging' menu choice you  will
see  a dialog box that lets you specify what events you  want
to  log and where to log them to: either to screen only or to
both the screen and a logfile.

The first two items deal with logging to a logfile. The first
one,  'Enable logging to file' switches writing to a  logfile
on  or  off. The second item, 'Logfile' is meant for entering
the  path  and  file  name into which all  the  messages  are
written.  Of  course, logging will only  work  when  a  valid
logfile  name  is  entered, it has to be  a  full  path  name
including a drive letter.

Serv-U  gives you a wide choice in what should be  logged  or
not. In all there are seven different categories that can  be
individually  enabled  or  disabled.  The  items   are   self
descriptive  except maybe for three: 'Log FTP commands'  logs
every  command as it is received by the server and  'Log  FTP
replies' logs the command replies that are sent back  by  the
server  to the client. These two options are mainly  intended
for  diagnostic purposes and are switched off by default. The
last  option is 'Log IP names' and when checked, Serv-U  will
try  to  find  the IP name of a user by doing a  reverse  DNS
lookup  on  the IP number. Keep in mind that DNS lookups  can
take  just  about any amount of time, cost a fair  amount  of
overhead,  and  not all IP numbers have a IP name  associated
with  it. When this option is checked the IP name of  a  user
will be logged as soon as it becomes available.

Messages  are always logged to the Serv-U window,  regardless
of  the logfile settings. There is no difference between  the
messages on screen and the ones in the logfile, although some
things  are  only shown on screen. The latter are server  and
program  related matters, like version number,  server  going
on/off-line etc.

Log  messages  always have the same layout.  The  reason  for
using such a strict format is to make it easier to search for
specific  messages  or certain types of messages.  This  also
makes  it  possible  to  do automatic accounting  by  machine
reading  the logfile if you need it. The logfile can be  read
or  copied at any moment, even when Serv-U is running (It  is
also  possible to get the file via FTP using Serv-U itself!).
The format is as shown below, in stylized form:

     [n] DATE TIME - (xxxx) MESSAGE

The first number, 'n', indicates the type of message that  is
being logged. Currently there are seven different categories:

     1    - system messages (problems etc.)
     2    - FTP commands (from client to server)
     3    - GET file transfers
     4    - PUT file transfers
     5    - security related events (users logging in etc.)
     6    - FTP replies (from server to client)
     7    - WinSock socket stack activity (only  used  for
            diagnostics)

The  second  number, 'xxxx', is a unique  ID  assigned  to  a
client  the  moment  the  connection  is  made.  All  further
messages  concerning that client will use  the  same  number.
Again,  this  was  done  to  make it  easy  to  do  automated
accounting,  or,  to  find  back events  using  the  'search'
facilities of every editor.

You  can  rename, move or delete a logfile at any time  while
the  server is running, there is no need to stop the  server.
You  can even copy a logfile to a remote system using  Serv-U
itself!  If you want to temporarily stop logging to file  and
see  it  on screen only, you can uncheck the 'File - Logging'
option  in  the  main menu. Needless to say this  has  to  be
checked to enable logging to file.

One more note: If you log GETs and PUTs then Serv-U will also
tell you the average transfer speed. For GETs the value Serv-
U  shows can be a bit optimistic, especially for small files,
as  a result of the socket stack buffering the bytes that are
sent over the network. Serv-U can very quickly transfer 10-20
Kbytes into the socket stack, which then proceeds to send  it
over  the network at its own leisure. However, Serv-U has  no
way  of finding out when the actual transfer is complete, and
assumes  that when it has sent the block to the socket  stack
it is done.

Enough boring talk, let's get back to the fun part! Next will
be  explained how you can pour your heart out to  your  users
through all kinds of messages.

2.10 How to Use Sign-on and/or Sign-off Messages
------------------------------------------------
Your  FTP-server can display a welcome message every  time  a
user connects to it. This can be very useful to provide users
with  information about your FTP server, like where  to  find
games, or 'Serious Software'. Likewise, you might want to say
good-bye to them when they leave, or remind them to send that
check  . . . The way to do this is by entering a text in  the
'Sign-on/Sign-off' dialog box which pops up when  you  choose
the 'Setup - Signon/off' menu choice.

There  are several special words that you can enter  in  your
sign-on and sign-off text which get expanded while being sent
to a client. They all begin with '%'. Here is the list:

     %Time       - displays the current time on your PC
     %Date       - displays the current date on your PC
     %UNow       - displays the current number  of  Serv-U
                   users connected
     %UAll       - displays the number of users since  the
                   server was started
     %U24h       - displays the number of users in the  last
                   24 hours
     %MaxUsers   - displays the maximum no. of users, as set
                   in 'Setup - Server'
     %MaxAnonymous - the maximum no. of anonymous users, as
                   set in 'Setup - Server'
     %Name       - displays the user's login name
     %IP         - displays the user's IP number or name  if
                   available
     %Dir        - displays the user's current directory
     %Disk       - displays the user's current disk drive
     %DFree      - displays the amount of free disk space on
                   the user's current disk in Kb
     %FUp        - displays the number of files uploaded  by
                   the current user
     %FDown      - displays the number of files downloaded
     %FTot       - displays  the  total  number  of  files
                   transferred
     %BUp        - displays the number of Kbytes uploaded by
                   the user
     %BDown      - displays the number of Kbytes downloaded
                   by the user
     %BTot       - displays  the total  number  of  Kbytes
                   transferred
     %TConM      - displays the total connect time in minutes
     %TConS      - displays the connect time in seconds - to
                   be used with '%tconm'
     %RatioUp    - displays the 'upload' ratio part for UL/DL
                   ratios
     %RatioDown  - displays the 'download' ratio  part  for
                   UL/DL ratios
     %RatioCredit - displays the current download  credit
                   for UL/DL ratios (Kb or 'files')
     %QuotaUsed  - displays how much disk quota is used in Kb
     %QuotaLeft  - displays how much disk quota is left in Kb
     %QuotaMax   - displays the maximum amount of disk space
                   that can be used in Kb

Not  all  of these directives make sense for both the  signon
and signoff text: There is little point in putting '%disk' in
the  signon  message, since the user is not  yet  logged  in.
Likewise  for  some  other directives.  However,  these  same
directives can also be used in directory change messages  and
login  messages, which are covered in the following sections.
There they can be very useful.

You could make the following signon text:

      Welcome, it is %time on %date, and you are user  number %unow
      Over the last 24 hours, %u24h people have visited  this site

I'm  sure  you'll figure out by yourself what this will  look
like to the user . . .
Please  keep  in  mind that the average client  has  only  80
characters per line, and the first four are taken up  by  the
reply code. So keep your lines short if you want the users to
actually see your prose.

2.11 How to Setup User Specific Login Messages
----------------------------------------------
After  astonishing the user with your signon message you  can
go  for  the  kill  by also providing a user  specific  login
message.  These messages should be put in one  or  more  text
files  and  the file name can be filled out in the  users  or
groups  setup dialog box, in the 'Message file' field of  the
miscellaneous part, i.e. press the 'Misc' button in the  user
or group box to get there.

The  file name you enter in the 'Message file' field can have
several forms: You can use an absolute path with a drive, for
example  C:\FTP\LOGMES.TXT. This will of course  make  Serv-U
use  this  file. You can also specify only the name,  and  no
path, for example LOGMES.TXT. This will cause Serv-U to  look
in the user's home directory for this file and if it is there
it will be displayed to the user. Finally, you can specify  a
path  but no drive letter, for example \FTP\LOGMES.TXT.  This
means  that  Serv-U  will add the drive of  the  user's  home
directory  to  make  a  full path. The  latter  two  ways  of
specifying the file can be very useful for groups, i.e.  with
just  a single file name set up you can provide all the users
that are part of that group with a separate login message.

Of  course,  you can use all the '%' directives mentioned  in
the previous section in login messages. Try for example:

     Hello %name from %IP!

With a little luck Serv-U will have found the IP name of  the
user  by the time he or she logs in. So you can impress  them
by   showing  you  know  where  they  are  (Big  Brother   IS
Watching!).  By the way, Netscape displays the login  message
in  a  nice looking way at the top of the screen (The sign-on
message does not get displayed by Netscape).

2.12 How to Use Directory Change Messages
-----------------------------------------
It  can be very useful to tell a user some specifics when  he
enters  a  directory. For this purpose Serv-U  has  directory
change  messages. There can be a different message  for  each
directory.

As with the login messages, the directory change message text
should be stored in a file. In the 'Setup - FTP Server'  menu
choice you can specify which file name Serv-U should look for
when  the  user changes directory. You can specify  the  file
name  in two different ways: First is an absolute file  name,
for  example  C:\FTP\CDMES.TXT. As  you'd  expect  this  will
display  that  file  for each directory change.  Then  it  is
possible  to  use  a  file name only without  the  path,  for
example CDMES.TXT. This will make Serv-U look for and display
the file with that name, in the directory into which the user
is changing. The latter one is the usual way to use directory
change  message files, since this enables you  to  specify  a
different message for each directory.

The  server  setup dialog box has room for  a  'primary'  and
'secondary' directory change message file. When looking for a
message file, Serv-U will first try the primary file name. If
there  is no file name specified in there, or the file cannot
be  found,  the  server will try to find the  secondary  file
name.  This  is  very useful in case you  have  specific  dir
change  message files for some directories, using a  relative
file  name as the primary directory change message file.  You
can  then  set  up  an absolute file name  as  the  secondary
directory  change message file. This will show the users  the
primary file message when available, and the secondary one if
there is no primary (For example because it's a CD-ROM so you
cannot   place   directory  change  message  files   in   its
directories).

Like sign-on and sign-off messages you can use any of the '%'
directives in directory change messages. Take a look  at  the
previous sections for a list of all directives.

Netscape will display those directory change messages at  the
top  of  the page. One more trick: If you enabled  the  'Hide
hidden  files' feature in the miscellaneous user  setup,  you
can  hide  the directory change message file itself from  the
user  by making it 'hidden'. Hidden files are files with  the
DOS/Windows  'hidden'  attribute set, something  you  can  do
using   the   DOS  program  'Attrib'  or  by   changing   the
'properties'  of  a  file  in Win95 (using  the  right  mouse
button). So, if you make your directory change message  files
hidden  they  won't show up in the directory  listings  while
users still get to see the messages.

2.13 How to Use Links a la UNIX
-------------------------------
Now  for  the  piece de resistance (pardon my French),  which
sets Serv-U miles apart from any other FTP server that I know
of for MS-Windows: Links!

If  you know UNIX then you know what I am talking about  when
links  are  mentioned. If not, then try the following:  Links
are  names  of  files and/or directories that appear  in  the
directory listing but they are not in the directory that  the
user  is  listing. Rather, they point to the actual directory
or  file and can be used by the user as if they were the real
thing  itself. A little like the Windows 95 'shortcuts',  but
more  real: When you delete a link through Serv-U the  actual
file  or  directory is gone! The great value of links  is  in
showing users that you have all kinds of goodies available on
other  disk drives. The user can then simply 'cd' to  a  link
and   thus  change  to  a  completely  different  drive   and
directory.

The  way  Serv-U works with links is by reading them  from  a
text  file.  You can have different files and thus  different
links  for  each  directory, much in  the  same  way  as  the
directory  change messages work in the previous section.  The
file  name  is  entered via the 'Setup  -  FTP  Server'  menu
selection  (Guess  where!). The server  setup  will  let  you
specify  a  primary and secondary link file. During  use  the
server  will first try to find the primary link file, and  if
that  one doesn't exit it'll try the secondary file name.  As
with  message  files there are several ways to specify  which
file  Serv-U should use for links: You can enter a file  name
by  itself, for example LINKS.TXT. This makes the server look
in the user's current directory for a file with this name and
if found it is merged into the directory listing. This is the
way  to  set up different link files for each directory.  The
second  method is by specifying a full path name, for example
C:\FTP\LINKS.TXT. As you'd expect the result will be that the
same  links  are  shown in each directory. Finally,  you  can
leave out the drive letter, for example \FTP\LINKS.TXT, which
means  Serv-U  adds the current drive to the  name  and  then
looks  for the file. Useful for setting up links that  change
per drive, but not per directory. If you make the link file's
attribute 'hidden' and enable the 'Hide hidden files' feature
in  the miscellaneous section of the user or group setup then
users  won't  see  the file itself appear in their  directory
listings while they still get to see the links.

In a typical situation you'd specify a relative path name for
the  primary  link file, and an absolute path  name  for  the
secondary link file. For example, if you enter the file  name
LINKS.TXT as the primary file name Serv-U will look for  this
file  in  the  users  current directory. This  lets  you  use
different  LINKS.TXT files for different directory, typically
with links specific to that directory. You'd then put all the
links you want to always show the user, even when they are on
a  CD-ROM,  in  a secondary link file with an  absolute  path
name, let's say C:\SERV-U\ABSLINKS.TXT. A good candidate  for
the  secondary link file would be a link to the  user's  home
directory.

Now, what should a link file look like? Each line of the file
describes a different link. First comes the link name,  which
is  what  the user is going to see in the directory  listing,
then a '|' which acts as a separator, and finally the file or
path  that the link should point to. Here is an example  link
file that should make all this a little clearer:

     D-Drive         | d:\
     CD-ROM          | f:\
     Home            | ~
     Fun Stuff       | g:\public\games
     One up          | ..
     Pointless       | \junk\..\more\..
     Poem            | c:\culture\poem.txt

As  far  as the user is concerned links behave like the  real
thing: They can be used for 'cd ' if it's a directory,  'get'
for  a  file  etc. Only difference is that  if  a  link  gets
deleted  the file or directory it points to will get  deleted
but  the  link  will  continue to show up  in  the  directory
listing. Needless to say that it is your responsibility  that
the links in a link file point to something that makes sense.

So  much  for the fun part, back to more serious matter  with
more  about how to select whom you want to let on your server
and whom to bounce.

IMPORTANT  NOTE: A point that seems to cause  much  confusion
and  is the source of much of the E-mail I'm receiving is the
effect of links and using the 'Show path relative to homedir'
feature in the miscellaneous dialog box of the user and group
setup.  People will make all these beautiful links  to  other
drives, CD-ROMs and the like, then switch on 'relative paths'
and  act surprised their links don't work. Once again,  while
using 'relative paths' Serv-U will try to show the users path
relative to the home directory for that user. This only works
for paths at or below the user's home directory. For example,
if   the   homedir   is  C:\USERS\JIM,   then   a   link   to
C:\USERS\JIM\UPLOAD will work fine, but a link to E:\PICTURES
will not!

2.14 How to Set Up Upload/Download Ratios
-----------------------------------------
Sometimes  you  want to force your users  to  upload  a  file
first, before they can download anything. Serv-U can do  this
for you, and more!

The setup for UL/DL ratios can be found in the user and group
setup  dialog boxes, by pressing the 'U/D Ratios' button.  In
general,  UL/DL ratios will let you specify how much  a  user
can  download for each upload. For example, if for a user the
ratio  is  set to 1 / 3 this means that for each  upload  the
user  can  download 3. So, after uploading  2  the  user  has
'credit' for 6.

Serv-U  can handle two types of ratios: Either it  will  keep
track  of  the uploads and downloads for each time  the  user
logs  in separately (the 'per session' settings), or  it  can
keep  track  of  file transfers over multiple sessions,  even
while several clients are logged in using the same user  name
(the  'overall' settings). For each of the 'per session'  and
'overall' choices Serv-U can count files (each file  uploaded
or downloaded counts as '1'), or it can count the actual file
sizes  in  bytes. Depending on which of the two is  used  the
ratio and credit setting will either mean 'files' or 'bytes'.

For  the  UL/DL  ratio  setting the actual  numbers  are  not
important. What counts is of course their ratio. For example,
setting  a upload/download ratio of 1 / 2 means (for 'files')
that each uploaded file gives the user two files 'credit' for
downloading.  Likewise, if bytes are  counted  each  uploaded
byte gives two bytes 'credit' for downloads.

Every  upload is converted into 'credit', and every  download
is  taken  from that credit. In a 'per session'  setting  the
credit  entry in the dialog box is intended for  entering  an
initial credit value that the user gets when logging in.  For
an  'overall' setting this is the actual current  credit  for
that particular user, which can be edited in the ratio setup.

There  is an important item which is closely related to UL/DL
ratios,  which  is named "free files". These are  files  that
will  not  be  counted for the upload/download  ratio  count,
something very useful for README.TXT files and the like.

"Free files" can be set up in the 'Setup Server' dialog  box,
by  pressing  the 'U/D Ratios' menu item. Just fill  out  the
file  name in the text edit box and press the 'Add' key. This
will  put  it  in the list which shows all the current  "free
files". The file name can be a name only, i.e. without  path.
That  way  any file with that name in any directory  will  be
free. For example, adding INDEX.TXT will make any file on the
system  with  that  name freely downloadable.  You  can  also
specify  a  full path in case only a specific file should  be
free.  For example C:\FTP\INDEX.TXT will make INDEX.TXT  free
only if it's in the C:\FTP directory. You can also leave  out
the  drive  letter,  which is taken to  mean  'for  all  disk
drives'.

The  free file names can contain wildcard characters: '*' and
'?'.  For example adding *.TXT will make all files ending  on
.TXT  free  on your system, or A???.TXT will make  all  files
starting with A followed by 3 other characters and ending  on
.TXT  free. Wildcard characters can also be used in  a  path.
For  example,  \*\*.TXT would make all files  on  all  drives
ending on .TXT free if they are in a sub-directory one  level
deep (like C:\FTP\INDEX.TXT would be).

2.15 How to Limit Disk Usage of Users
-------------------------------------
Unless  you  have  deep pockets and consequently  large  hard
disks you are going to want to limit the amount of disk space
that  your  FTP users can occupy. Again Serv-U comes  to  the
rescue  by  letting you specify exactly how much a  user  can
use.

For  this  purpose the user and group setup  boxes  have  the
'Quota' button which brings you to the disk quota dialog box.
In  there  you  have  two items: One to specify  the  maximum
amount  of  disk space a user can use, the other  to  specify
what  the  current amount is. Even though  the  setup  is  in
Kbytes, internally Serv-U is accurate up to the byte.

The  current amount lets you set up an initial value, in case
you are filling out the user's details for the first time. It
also  keeps track of the disk usage as time goes by, and  you
can thus change it whenever you feel like it.

2.16 How to Limit Access by IP Number
-------------------------------------
The  'Setup - IP Access' menu choice will pop up a dialog box
which  provides  the  means to restrict access  to  your  FTP
server to certain IP-numbers. If  for example, you work at  a
university and only want your faculty members to be  able  to
access the server, then this is a great way to do it. In  the
upper left corner of the dialog box you can choose which type
of  rules  you want to specify: 'Deny' or 'Allow' rules.  The
deny  rules  decide who should be kept out, the  allow  rules
indicate  who should be welcomed. THE ORDER OF THE  RULES  IS
IMPORTANT! When a client contacts the server, the  rules  are
looked  at  FROM  TOP  TO  BOTTOM. The  first  matching  rule
applies, and evaluation is stopped. If there are no IP-access
rules everybody can enter the FTP server. As soon as there is
one  rule,  only those clients that pass the rule  check  are
allowed to enter.

You  can  select which type of rules you want to have  Serv-U
evaluate  first,  in  case  both deny  and  allow  rules  are
present. Just select the right one in the 'Evaluation  Order'
part.  This can be useful in case you need to specify  a  few
exceptions to a general rule.

You  can  type in a new rule in the 'Rule' edit and then  use
the  'Add'  button to add the rule to the list. The  'Remove'
button will remove the currently selected rule from the list.
To  change the order of the rules you have to select  one  by
clicking  the mouse on it, and then use the 'Up'  and  'Down'
buttons to move it around.

Rules  are  nothing more than IP-numbers  or  ranges  of  IP-
numbers. There are two special characters: the star  '*'  and
the  hyphen '-'. A star functions as a wildcard for  checking
the number. Any number will match that section of the rule if
it  is  a  star.  The  hyphen is used to denote  a  range  of
numbers. Simply separate the starting and ending values by  a
hyphen. For example, say all IP-numbers in your company  look
like 134.56.34.xxx with 'xxx' being any number. Now, you want
to  restrict  access to your FTP server to other  members  of
your  company only. The way to do it is to create an  'Allow'
rule that looks like this:

     134.56.34.*

That's  simple,  isn't it!? Likewise, if you  know  that  the
competition  has IP-numbers in the range 168.76.xxx.xxx,  you
can keep them out of your server with the 'Deny' rule:

     168.76.*.*

Now,  you  need  to  share some of  your  files  with  a  few
colleagues,  and management in your company is too  cheap  to
install a local network. You find out that their PC's have IP-
numbers  134.56.34.128, 134.56.34.129 and 134.56.34.130.  You
could  of course make three 'Allow' rules, each with  one  of
these  numbers. A faster way to do this is to make  a  single
rule like this:

     134.56.34.128-130

The  special characters '*' and '-' don't need to be  at  the
end  of the IP-numbers, any place will do. The rule 221.*.76-
154.89 is perfectly OK. I wouldn't know when you'd need this,
but,  hey, the world is a strange place! Remember,  order  is
important  and  deny  rules are always evaluated  before  the
allow rules. Experiment a bit, and you'll get the hang of it.

Since  people  keep  asking me this: A few  words  about  the
security  of  IP-access rules. The check on IP number  stands
pretty  much at the top of the Serv-U security mechanism  and
all  connections  have  to pass through  this  rather  narrow
bottle  neck. The code that does the checking is quite simple
(In  contrast to the code that does the access rule  checking
for paths), so it is unlikely that there are any loopholes or
bugs  left in there. So, in my humble and honest opinion this
is  one  feature that makes for a very secure FTP  server  if
that is what you need!

2.17 How to Print via FTP
-------------------------
Serv-U  also  allows  access to all PC  ports:  PRN:,  LPT1:,
LPT2:,  LPT3:, LPT4:, AUX:, COM1:, COM2:, COM3:,  and  COM4:.
This  can  be  a  convenient way of setting  up  a  'network'
printer by transferring files directly to PRN: or LPT1: using
FTP. These ports are treated like any regular path name, so a
user needs access rights to use them. Thus, to make a printer
on  PRN:  accessible and a modem on COM2: the user needs  the
following  access  rights in the 'Setup Users/Groups'  dialog
box:

     PRN:                  - write and delete rights
     COM2:                 - read, write and delete rights

There seems to be much confusion on how to actually use  this
feature,  therefore a short explanation. These  ports  behave
very  much like files that always exist and can be  found  in
every  directory  although they don't show  up  in  directory
listings. So, no 'cd' commands are needed, just transfer your
file-to-print  to the port with the printer.  For  a  command
line  FTP client this would look like 'put FILE.TXT PRN:'  to
print  file FILE.TXT on a printer attached to port PRN:.  For
point-and-click type FTP clients you have to specify that  it
should  ask  you  for the destination file name.  Then,  when
prompted  for the destination file name you enter  'PRN:'  or
another  port  of your choice. For example, for  the  popular
client  WS_FTP you have to check the 'Prompt for destinations
file  names'  option in the 'Session Options' section.  After
doing  that  you can simply upload the file-to-print  and  it
will  ask you for the destination, for which you fill in  the
printer port name.

The  above procedure should work well to print ASCII text and
text-based   protocols  like  PostScript  (If  your   printer
supports  it).  However, with binary files your  mileage  may
vary:  It seems that the port closes when a ^D is encountered
in the stream that is being printed.

2.18 How to Execute Programs via FTP with Serv-U
------------------------------------------------
Serv-U  allows you to start DOS or Windows programs  remotely
using a FTP client. Keep in mind though that Serv-U is not  a
Telnet  server,  and any program output or  windows  will  be
displayed  at  the PC where Serv-U is running.  However,  for
many  applications the ability to start a program is  enough,
or  you might be able to redirect input and output, i.e. like
'MYPROG.EXE < INPUT.TXT > OUTPUT.TXT'.

The  first  requirement to using remote program execution  is
that  the  user needs sufficient access rights to  start  the
desired programs. This is controlled by the 'execute'  access
right  in the 'Setup Users/Groups' dialog box. You can either
give a user execute access to the directory where the program
can  be found, or you can specify the exact program name. For
example,  if  we  want  to  be able  to  execute  COMMAND.COM
remotely,  and  this  program can  be  found  in  the  C:\DOS
directory, then the following access rule would do the trick:

     C:\DOS\COMMAND.COM    - execute access

Now, to actually start a program remotely you need to use the
FTP  command  'SITE  EXEC' from the FTP client.  Usually  you
cannot  do that directly, since the client doesn't understand
this command, and you need to tell the client to send it as a
literal string to the server. for example the UNIX FTP client
(and  others like it, as the one that comes with  Windows  95
and  NT)  uses the 'QUOTE' command for this purpose.  So  the
full  command line to let COMMAND.COM copy a file from  A.TXT
to B.TXT would become:

     QUOTE SITE EXEC C:/DOS/COMMAND.COM COPY /B A.TXT B.TXT

You  might notice the use of '/' instead of '\' in the  path.
This  is  because most command line FTP clients do  not  take
kindly to backslashes. For Serv-U it doesn't  matter and  you
can  use  '/'  and '\' alike. You can also  see  that  it  is
possible  to  specify  arguments to a program  as  you  would
usually do, Serv-U passes them on to the program. The example
above will likely only work for command line FTP clients that
are  based  on  the  UNIX  client. For  point-and-click  type
clients, like WS_FTP you are on your own. They may or may not
have  the ability to send literal commands to the server  but
the way to get that done will vary from client to client.

Starting programs remotely may not be as straight forward  as
it  seems,  and  can  have varies side  effects.  Also,  some
programs  need  to  be  started via the command  interpreter,
COMMAND.COM,  others not. In short: Some  experimentation  is
recommended!

One  more  important thing about 'execute'  access:  Although
Serv-U checks the program's path for access, the program  you
start  this way is free to access and delete any file in  any
directory  on  your  computer! Also, if  you  give  'execute'
access to a directory then any program in the DOS path can be
started! In short: Be very careful with 'execute' access,  as
this is a very big potential security hole!

2.19 How to Use Serv-U with 'SLIP/PPP Emulators'
------------------------------------------------
More  and  more  Internet  Access Providers  these  days  are
offering Internet connections that are not 'real'. Instead of
having  their own IP address these connections run on top  of
the  IP  address of a UNIX host system. The general name  for
this  category of connections is 'SLIP/PPP emulators'  and  a
few of the popular programs that will do that are 'TIA' (=The
Internet  Adapter),  'TWinsock', and 'Pipeline'.  The  reason
ISP's use them is because they offer a cheap way to get  many
people  connected  to  the net. They usually  work  fine  for
programs  like Netscape, mail, and FTP clients. However,  for
servers they come with a number of build-in disadvantages.

Because  of  the way they have to do their work they  have  a
number  of  peculiarities. Since the PC has to share  the  IP
number with the host system you will generally not be able to
use  the default port 21 for Serv-U. Instead, you either have
to  use  a high port number (generally above 8000) or set  up
'port  redirection'. Ask your Internet provider  for  details
about  the  latter. A related problem is that the  IP  number
displayed by Serv-U is, in this case, not the IP number  that
clients  should use to contact your server. It  is  merely  a
dummy  to  keep  the socket stack of the PC  happy.  For  the
outside  world the IP number of your server is  the  same  as
that  of the emulator host system, i.e. that of your Internet
provider. Another special effect is that clients will not  be
able  to  use 'passive' mode for data transfers.  This  means
that  regular FTP clients will work OK, but WWW browsers like
Netscape and Mosaic will not work when Serv-U runs via a SLIP
emulator.  For  the same reason it won't be possible  to  use
clients that are also connected via a SLIP emulator either.

Just  in  case you are interested I'll give you the technical
details  behind all this. Since Serv-U has to  share  the  IP
number  with the Internet connection host system  (Usually  a
UNIX system), the usual FTP port (number 21) will most likely
be  already in use by the host system. Because at a single IP
address there is only a single port 21 this means either Serv-
U  or  the host has to move to another port. The second  side
effect has to do with the socket stack: They usually need  to
know  their  own IP address to do the work, and to  keep  the
stack  happy  it is installed with a non-existent  IP  number
like  192.0.2.1  (Seems  to  be a popular  choice).  The  FTP
protocol  does  not use the server side IP number  much,  the
only  exception is the FTP 'PASV' command, which is used  for
passive mode data transfers (Which all WWW browsers use).  In
essence, what the PASV command does is ask the server for  an
IP  address and port number where it will listen for the data
connection.  Since  the FTP server does  not  know  that  its
address  is bogus, it will trustfully report this  back.  The
client will then try to connect to this dummy address,  which
of course will never work.

2.20 How to use Netscape to access Serv-U
-----------------------------------------
You  might  not  be aware of it, but Netscape and  other  WWW
browsers  can  do  a whole lot more than just  anonymous  FTP
access. The general syntax for FTP is the following:

     FTP://<user>:<password>@<IP address>/<path/file>

Very  little of this is needed and in its simplest  form  you
only  use  the  <IP  address>  which  results  in  the  usual
anonymous  access. If you add a <user> section  (leaving  out
the password) then Netscape will prompt you for a password if
needed.  Of  course,  you can also specify  the  password  by
yourself by adding the <password> section. So far we did  not
use  the <path/file> section and this means the user will end
up  in his or her home directory. If you want to go somewhere
else  you  can tell Netscape to do this with the  <path/file>
section.

In the <path/file> section you should use '/' instead of '\',
and  you can add a drive letter as part of the path.  So,  to
finish up with an example that uses all of the above:

     FTP://john:[e-mail]/f:/john

This would log John into the Cat Soft server.

By  the  way, did you know that the version 2.0 or  later  of
Netscape  can also upload files to a FTP server?  To  do  so,
simply  drag  the file-to-upload from 'Explorer'  (the  Win95
file  manager), or from the 'File Manager' (in NT or  Windows
3.1)  to the Netscape window and drop it there. Experiment  &
Enjoy!

2.21  How to Let the Whole World into Your Server (and Delete
      All Your Files)
-------------------------------------------------------------
Even  for  those with a PC-oriented exhibitionist inclination
Serv-U  has  something to offer. You can let the whole  world
into your server and have them delete all your files. To  top
it off, if set up correctly they will reformat your hard disk
along the way too!

The  easiest  way to all that fun is to uncheck  the  'Enable
security'  checkbox in the 'Setup Server'  dialog  box.  This
utterly  and completely disables all security in  the  server
and  thus offers the most comfort to your FTP users. Not only
can they freely copy and delete each and every file, they can
also  use  the  unique Serv-U feature that  lets  them  start
programs  remotely.  Of course, the fun  is  over  once  they
remotely  start FORMAT.COM, but what the heck,  it  was  nice
while it lasted!

Now,  for those that are a bit 'sarcasm inhibited' I'll spell
it  out:  NEVER,  NEVER,  NEVER LEAVE THE  'ENABLE  SECURITY'
OPTION  SWITCHED  OFF  IF YOUR SERVER  IS  CONNECTED  TO  THE
INTERNET!!!  This might all seem a bit overkill, but  believe
it or not, I quite regularly get E-mail from people that tell
me  they are running Serv-U exactly like that on the Net. Now
don't tell me I didn't warn you.

2.22 How to use multi-homed IP support
--------------------------------------
If  your  operating system supports it, and you have multiple
IP  addresses installed at your computer (Typically  this  is
done  in  NT),  you  can let Serv-U respond  differently  for
different IP addresses that the users connects to. To make it
a  little  clearer  a  small example: Say  you  have  two  IP
addresses   assigned   to   your   PC,   152.3.110.167    and
152.3.110.168,  which  correspond  to  IP  names   "ftp1.cat-
soft.com" and "ftp2.cat-soft.com" respectively. Now you  want
anonymous  users logging into the "ftp1" IP address  to  have
access  to different files and directories from those logging
into "ftp2". This is called multi-homed IP, and supported  by
Serv-U.

The  first step to using this is in the 'Setup Server' dialog
box.  Press the button labeled 'IP Homes' in there. Then  use
the  screen that pops up to enter all the IP numbers of  your
PC.  When this is done you can go to the 'Setup Users' dialog
box,  which will now show a new selection list with all  your
IP  numbers.  Just set up the users as you  did  before,  and
select  the  appropriate IP number that should be  associated
with  that  user name.  This will allow you, for example,  to
make  several  users  named 'anonymous', each  responding  to
different  IP addresses. That's all there is to using  multi-
homed IP, it could not be easier!


3. THE INNER WORKINGS
=====================

Before  I  go  on to describe the settings of the  SERV-U.INI
file  I  want to spend a few words describing how Serv-U  was
made and how it goes about its job.

3.1 Serv-U Internals
--------------------
The  program was written using Borland C++ version 4.52  (for
the 16-bit version) and version 5.0 (for the 32-bit version).
To  check  for  shaky pointers and catch all  those  resource
leaks  the  program Bounds Checker version 3.01 from  Nu-Mega
was  used.  I think no serious Windows programmer  should  be
without the latter, very highly recommended!
This  whole project started a little over two years ago after
much  disappointment  with  the  existing  FTP  servers   for
WinSock.  In its current version it consists of  a  bit  over
22000  lines  of C++ code, divided into 41 C++  classes.  The
whole  program  was constructed from scratch, not  using  any
existing  FTP server code, and is tailored to MS-Windows  and
WinSock.

Internally, everything is very much compartmentalized,  using
a  different class for different partial tasks.  There  is  a
WinSock  class library, providing hi-level access to  Windows
Sockets and hiding all the nasty parts of dealing with  them.
It   uses   100%   asynchronous  WinSock   functions   (which
unfortunately  do not always work correctly on  a  number  of
WinSock  stacks) thus avoiding problems with multiple  active
sockets  for  a  single task and re-entry. There  is  a  FTP-
manager  class,  taking care of listening  for  clients,  and
setting  up  instances of the FTP-command  interpreter  class
when  this happens. The latter does the actual interpretation
of  the  FTP  commands,  talking to the  security  class  for
clearance  and  the  WinSock class for  communications.  Then
there are some utility-like classes, like those dealing  with
setup  and  logging.  By having all these  compartments  that
handle  very well defined tasks, I hope to be able to  easily
extend  this  FTP  server  and  fix  those  (hopefully   few)
remaining bugs quickly!

The  32-bit version of Serv-U is not multi-threaded, a single
thread  is used for all clients. 'Multi-threading' is one  of
those  buzz  words  that are poorly understood  by  most  and
abused  by  many. 'Threads' are light-weight processes,  that
can  be used to run concurrent tasks without all the overhead
of  creating real processes. In the mainframe world this  has
traditionally been used for servers: Each client would  start
a separate process or thread. However, unless you are running
NT  on a multi-processor machine (and I wager that now we are
talking  about  much  less than 1% of all NT  installations),
multi-threading is not generally going to gain  you  anything
because thread maintenance and switching brings overhead with
it.  There are still good reasons for using multiple  threads
on  a  single  processor machine: For independent  background
tasks, like a printer spooler, it makes perfect sense.  Also,
if  a process needs to perform multiple concurrent tasks that
each  would  take a long time (and 'long' in  computer  terms
could  mean anything over a few tens of milliseconds),  using
multi-threading is a good practice. However, for servers  the
practice  of  starting a separate thread for each  client  is
usually to provide an easy way out of programming the  thing.
That way the programmer can use 'blocking' sockets and simply
block  (i.e.  'do nothing') until something  happens  on  the
socket stack. Makes for much simpler programs and is used for
all  the UNIX servers, so anything ported from there will  be
coded in this fashion. The better way to do things in Windows
is  to  make  the program event-driven and let it respond  to
messages from the socket stack instead of blocking the  task.
This  means 'asynchronous' sockets have to be used,  and  the
whole  program is much harder to make: Instead  of  a  single
easy  to  follow  flow the program now becomes  a  number  of
message  handler routines that can be called  in  any  order.
Serv-U  only  uses asynchronous sockets, and the response  to
each  socket stack message normally does not take much  time.
Thus,  a  single thread can handle this perfectly  well,  and
cutting  it  up  in multiple threads would only  slow  things
down.

3.2 The SERV-U.INI File
-----------------------
All the settings for the server, users, and groups are stored
in  a  single file in text format. This file is always  named
SERV-U.INI.  When the program is started it  looks  for  this
file  in  a  number of different places: First the  directory
with  SERV-U.EXE  is checked. If no .INI  file  is  found  an
environment  variable  SERV-U is checked.  If  this  variable
exists  it  should  be  set to the path where  SERV-U.INI  is
found.  Finally, if this variable does not exist,  the  whole
DOS  path is scanned, including the Windows directories.  The
first SERV-U.INI file found on the way is used. If after  all
the  above  no  .INI file has been found,  the  program  will
create  one in the directory of  the Serv-U program.  Use  of
the  SERV-U  environment variable and the DOS path  makes  it
easy  to  set things up for network users where  there  is  a
single copy of the program but all the users needs their  own
settings. Serv-U uses the Windows built-in functions to  read
and  write  from/to the .INI file. A consequence of  this  is
that  the total size of SERV-U.INI can never exceed 64 Kbytes
on  Windows 3.1, 3.11 and Win95, limiting the number of users
that  can be set up. On NT there seems to be no limit to  the
.INI file.

We'll  now  go  over all the items that can appear  in  SERV-
U.INI. I will show you an invented setup file:

     [GLOBAL]
     Security=TRUE
     PortNr=21
     MaxNrUsers=15
     MaxNrAnonymous=10
     Invisible=TRUE
     Logfile=c:\serv-u\logfile.txt
     Logging=YES
     TimeoutUser=600
     TimeoutAnonymous=15
     TryOut=Crippled
     LogGETs=ON
     LogPUTs=ON
     LogSystemMes=ON
     LogSecurityMes=ON
     LogFTPCommands=OFF
     LogFTPReplies=OFF
     LogIPNames=ON
     RegistrationKey=S%FgdfsdEvG,Rob Beckers,Cat Soft,1
     Window=100,100,400,300
     UserInfoWin=409,300
     DirChangeMesFile=index.txt
     DirChangeMesFile2=c:\serv-u\index.txt
     LinkFile=link.txt
     LinkFile2=c:\serv-u\link.txt
     CheckAnonPass=OFF
     Version=2.0.3.11
     StartIconic=No

     [SIGNONOFF]
     SignOn1="Welcome to Robby's FTP-Server!"
     SignOn2="It is %time on %date and you are user no. %unow"
     SignOff1="Thanks for logging in!"
     SignOff2="Hope to see you again soon . . ."

     [IP-ACCESS]
     DenyRulesFirst=YES
     Bounce1=132.68.175.201
     Bounce2=223.*.*.*
     Allow1=132.68.176.53
     Allow2=132.68.175.*
     Allow3=101.43.23.30-40

     [USER=Anonymous@2]
     HomeDir=d:\anonftp2
     Access1=d:\anonftp2\upload,WP
     Access2=d:\anonftp2,RLP
     LoginMesFile=logmes.txt
     HideHidden=YES
     RelPaths=YES
     RatiosEnable=YES
     Ratios=BytesPerSession
     RatioUp=1
     RatioDown=7
     RatiosCredit=19968.000000

     [USER=Anonymous@1]
     HomeDir=d:\anonftp1
     Access1=d:\anonftp1\upload,WP
     Access2=d:\anonftp1,RLP
     LoginMesFile=logmes.txt

     [USER=Rob]
     Group=system
     Password=WdRx.Jlk0kemm%
     HomeDir=c:\
     AlwaysAllowLogin=YES
     QuotaEnable=YES
     QuotaMaxCurrent=10240000,89739
     Access1=\,RWMCDLPE
     Access2=lpt1:,WM
     Access3=prn:,WM
     Access4=aux:,WM
     Access5=lpt2:,WM
     Access6=lpt3:,WM
     Access7=lpt4:,WM
     Access8=com1:,RWM
     Access9=com2:,RWM
     Enable=YES

     [USER=ALL]
     HomeDir=y:\
     Access1=y:\,RL
     Enable=NO

     [GROUP=SYSTEM]
     Access1=c:\system,RWDCMLEP
     Access2=d:\,RWDCMLEP
     Access3=y:\novell,RWDLP

     [RATIOS]
     Free1=*.txt
     Free2=\*\*.bat
     Free3=d:\gifs\sample.gif

     [IP-HOMES]
     IP1=152.3.110.168
     IP2=152.3.110.169

     [EXTERNAL]
     ClientCheckDLL1=CHKNOVELL.DLL
     ClientCheckDLL2=CHKNT.DLL


All  but  five  of  these settings can  be  changed  and  set
interactively  through the 'Setup' menus. The exceptions  are
the  entries  for  'Invisible', 'RegistrationKey',  'Window',
'UserInfoWin', and 'StartIconic', and if you really desire  a
user  to have no password, that user's 'Password=' entry  has
to  be  set  manually (i.e. nothing after  the  '='  sign  to
indicate 'no password').

The following paragraphs will describe each section and entry
in more detail.

[GLOBAL]
All  the settings related to the Serv-U program itself,  i.e.
the  functioning of the FTP server and system functions,  are
found  in  the  '[Global]' section. For the file  formats  of
directory change message files and  link files please see the
appropriate 'How to .' section.

If  security should not be enforced, the 'Security' entry can
be set to FALSE or 0. Doing so will leave the FTP server wide
open to everybody!!! Default value for 'Security' is TRUE.

The  'PortNr'  entry determines the IP port that  the  server
will listen on. Default value is 21.

To  limit  the  maximum  number  of  simultaneous  users  the
'MaxNrUsers'  entry should be set to the desired  number.  No
entry  or  a negative number results in no maximum, only  the
number of available sockets will limit the number of users in
that  case. Similarly, the 'MaxNrAnonymous' entry limits  the
maximum  number of 'Anonymous' users. The value put  here  is
only   meaningful  if  it  is  smaller  than  that   of   the
'MaxNrUsers' entry.

For  system  managers  that don't want their  users  to  mess
around with the server settings, it is possible to make Serv-
U  invisible by setting the 'Invisible' entry to TRUE, or YES
and  put the Serv-U program in the 'startup' group. When this
is done the server will not show up in the task manager list.
One  consequence is that there is no way to stop the  program
short of exiting Windows. Default is NO for this entry.

The 'LogFile' entry should specify a full path and name for a
logfile  if logging is desired. There is no default  logfile.
To actually switch logging on and off the 'Logging' entry can
be  set to ON or TRUE, or OFF or FALSE. Switching logging  ON
will  only  work  if  a  logfile  is  specified.  By  default
'Logging' is set to ON.

The  entries 'TimeOutUser' and 'TimeOutAnonymous'  specify  a
time-out  in  minutes  for  respectively  regular  users  and
anonymous  users. If a FTP connection is left  idle  for  the
indicated amount of time it is automatically closed.  Filling
in  0  results in no time-out. Default values are 15  minutes
for anonymous and 10 hours for regular users.

The  next one deals with the way the program can be tried out
(when  there  is  no  registration  code).  'TryOut'  can  be
'Crippled' or 'Full'. The first allows a user to do a maximum
of  5  GETs and 5 PUTs per session, switches the server  off-
line after 1 hour, and notifies clients that they are looking
at  an  unregistered try-out version. However,  it  does  not
contact my permission server. The 'Full' option gives you  no
limitations while trying the program, it is exactly equal  to
the  registered version. The downside is that it does  access
my  permission server to ask for permission to run each  time
Serv-U  is  started. This is how the 30 days of  try-out  are
enforced.

All  the 'LogXXXX' entries switch logging options on or  off.
Their names say it all, so I'll let you figure them out.

The   'RegistrationKey'  entry  is  used  for  entering   the
registration  code. You get this code after registration.  By
default it has no value and for evaluation of the program  it
should be left blank or out of the .INI file.

The  next  entry is 'Window' and this is set by Serv-U  every
time  the  program is stopped. It contains the last  position
and   size   of   the   program   window,   in   the   format
'top,left,width,height'. Likewise,  'UserInfoWin'  saves  the
window position of the user information window, in the format
'top,left'.

Related  to this is 'StartIconic' which stores if the program
should  start  as an icon. This happens when the  server  was
stopped while being iconized.

To  enable  directory change messages you  have  to  set  the
'DirChangeMesFile' entry to a valid file name. This can be  a
complete  path  name, in which case the  same  file  will  be
displayed  for  all path changes, or it can be  a  file  name
only, which means Serv-U will look for that file in the  path
the  user  is  changing to. Likewise, 'DirChangeMesFile2'  is
used  in case the file specified in 'DirChangeMesFile' cannot
be found.

If  links  should be available and displayed  in  the  user's
directory listings then 'LinkFile' should be
set to the file name to use. The file name format is the same
as for 'DirChangeMesFile'. In case 'LinkFile' cannot be found
the server looks for 'LinkFile2'.

To  check if anonymous 'passwords' resemble an E-mail address
you can set 'CheckAnonPass' to YES, ON or TRUE. Likewise, you
can  switch checks off by setting it to FALSE, NO or OFF, and
this  is  also  the default. In that case Serv-U  will  allow
anything as an anonymous password.

Finally, 'Version' keeps track of the Serv-U version  number.
Format is 'major,minor,revision,build no.' and it is used for
automatic .ini file conversion.

[SIGNONOFF]
This section contains the messages that are displayed after a
user  contacts the FTP server and just before he disconnects.
Every  line  has a separate entry with a number at  the  end,
denoting  the order. The sign-on message is put in 'SignOnxx'
entries  (with xx the line number), and the sign-off  message
is put in 'SignOffxx'.

There  are  several special character combinations recognized
by Serv-U and they are expanded to their actual values when a
user logs on or off. They all begin with '%' and you can find
a  complete  list in the 'How to use sign-on and/or  sign-off
messages' section.

A tip: Keep the number of lines and the their length limited.
Most  FTP clients will mess up lines over 80 characters,  and
since  a  FTP reply code is tagged to the beginning of  these
lines  before they are sent, it is wise to keep them to  less
then 75 characters.

[IP-ACCESS]
This  section  determines  which client  IP-numbers  will  be
allowed access to Serv-U. There are two kinds of rules: Those
that refuse access in the form of 'Bounce' entries, and those
that  grant  access using 'Allow' entries.  If  this  section
doesn't exist, or no entries are found, then all clients  are
allowed  to contact the server. The reverse is also true,  if
there is even a single entry ('Bounce' or 'Allow') then  only
those clients will be allowed to contact the server that pass
the  rule.  All entries are numbered sequentially  ('Allow1',
'Allow2'  etc.)  and  they are evaluated according  to  their
number from first to last. Numbers should be consecutive. The
'Bounce' rules are evaluated before the 'Allow' rules.

The IP-number of the client is matched section by section  to
each rule until a match is found. If the matching rule is one
of  the 'Bounce' rules, the client is disconnected. If the IP
number matches an 'Allow' rule then he can proceed. The rules
can be exact IP-numbers, or contain special characters. There
are two of those:

     *    = wildcard, match any number
     -    = denotes a range

A  quick example: The rule '132.*.76.48-89' will allow  entry
to  clients with an IP-address starting with 132, the  second
section  can be anything (0..255), the third must be  76  and
the  last  section  should  be  between  48  and  89  (limits
included).

The  'DenyRulesFirst' flag is used to specify in which  order
the  access rules should be evaluated: The 'deny' rules first
and  then the 'bounce' rules, or vice versa. Default this  is
set to YES.

[USER='Name']
The  information  about  a user is stored  in  this  section,
'Name'  stands for the user's name. Each user has a  separate
section.  It  contains information needed to  authenticate  a
user  during login, and rules determining what this  user  is
allowed  to access. The Serv-U program will first check  this
section  for a regular user. If no applicable information  is
found  and  the  user is a member of a group,  the  group  is
addressed for the same information. If the result of this  is
still undetermined, the special user name 'ALL' is searched.

Now  to  the  entries that can be found in this section.  The
identity  of  a  user is verified by comparing his  password,
after  encryption, with the one in the 'Password' entry.  The
UNIX  'crypt()' command is used to encode the passwords. This
makes  it possible to extract users with their password  from
the  PASSWD file of a UNIX system, the same passwords  should
work  on  both systems. Unfortunately, there is not a  single
standard for password encryption on UNIX systems these  days.
Serv-U  uses the most common scheme, but this might not  work
for your system.

If  the  password matches, the home directory of the user  is
taken from the 'HomeDir' entry. This should always be a  full
path name, including drive letter!

To make a user a member of a certain group, the 'Group' entry
can  be  used.  All information needed and not found  in  the
user's section; password, home dir and file/directory access,
are then  looked for in the group's section.

Information  about file and directory access for  a  user  is
stored  in  the 'Access' entries. Each of these is  numbered,
and  access information is checked in order: first  comparing
it  to  the  first rule, then the second, etc. The  numbering
must  be consecutive. Access rules start with a path or  file
name.  These  paths are usually full names,  including  drive
letter.  If  the drive letter is missing, they apply  to  all
drives.  If different settings are needed for a subdirectory,
then  a  rule  with that directory should appear  before  its
parent,  i.e. with a lesser number (As a consequence  of  the
order in which Serv-U evaluates access rules). The path in an
access rule is followed by a comma and the access information
itself.  This  can be a combination of up to eight  different
characters:

     R    = read access to files
     W    = write access to files
     M    = modify access to files (implies write access)
     E    = execute access, for remotely starting programs
     C    = right to create subdirectories
     D    = right to delete subdirectories
     L    = directory list access
     P    = the rule 'propagates' to sub directories as well

It  is entirely possible to have no access information at all
(only  a  path). This means that the user will not  have  any
access  to  that  path. One thing to realize  is  that  write
access  to a file does not imply read access! As you can  see
it is also possible to specify access rights for the parallel
and  serial  ports.  They are part of  the  regular  security
scheme  and to transfer to or from a port a user needs access
rights.  Then  finally, the path in an access rule  does  not
have  to point to a directory. It is also possible to specify
a filename. Of course, the 'C', 'D', 'L', and 'P' rights will
not have any meaning then.

There  are two special user names: 'Anonymous' and 'ALL'.  If
there is an user 'Anonymous', it will be possible to log into
the  server without a password. Instead, Serv-U will ask  for
the  user's E-mail address and log this. Most of the  regular
entries apply for 'Anonymous' as well, except 'Password'  and
'Group', these are ignored. In fact, for anonymous users  the
sections for groups and 'ALL' are never searched.

The user 'ALL' is searched if no appropriate rule is found in
a  user's or the user's group's entry. It can contain any  of
the regular entries.

The  user account can be disabled by setting 'Enable' to  NO.
By default accounts are enabled.

'RelPaths'  determines if users should be  treated  with  all
path  names  relative  to  their  home  directory.  This   is
desirable  for  use with WWW browsers that insist  on  having
access  to the root directory ('/'). Switching this on limits
users  to  the sub-tree of their home directory, they  cannot
switch to other drives. If you switch it off then users  will
see their full path. Default is switched off.

The  'LoginMesFile'  entry is used for pointing  to  a  login
message file that should be displayed to the user upon login.
The  same file name rules apply as for the 'DirChangeMesFile'
entry,  and you can find more details about its usage in  the
'How to setup user specific long messages' section.

The  user  heading  can contain an added '@'  followed  by  a
number,  like '[USER=Anonymous1@1]'. This indicates that  the
user name is associated with a particular IP number for multi-
homed IP support. A list with IP numbers and their index  can
be found in the '[IP-HOMES]' section.

In  case  'HideHidden' is YES or TRUE all the files with  the
'hidden'  attribute  will not show up in directory  listings.
Default  this is NO. In case a user should always be  allowed
to  log  in,  even  when  the  user  limit  is  reached,  the
'AlwaysAllowLogin' setting should be TRUE or YES. Default for
this is NO.

The  UL/DL  ratio settings are also part of  the  user  setup
info.   To   enable  the  use  of  ratios  for  a  user   the
'RatioEnable' setting should be set. The type of ratios Serv-
U  will  use is controlled by 'Ratios': The four options  are
'FilesPerSession'  which  counts  files  for  each   session,
'BytesPerSession'  which  counts  bytes  for  each   session,
'FilesOverall'  to  count  files  over  all   sessions,   and
'BytesOverall' which is for counting bytes over all sessions.
The  'RatioUp'  setting  specifies the  upload  part  of  the
upload/download equation, and 'RatioDown' is for the download
part.  The  credit is stored in 'RatiosCredit', depending  on
the  type  of ratios used this can be in 'files' or  'bytes',
and  it can be a preset value for each session or the current
credit in case ratios are counted over all sessions.

In  case the user's disk usage should be limited, disk  quota
limitations can be switched on by enabling 'QuotaEnable'. The
'QuotaMaxCurrent'  value  keeps  track  of  the  maximum  and
current disk usage values in bytes.

[GROUP='Name']
These  sections contain the group info. The entries here  are
exactly the same as those for a user, except that the 'Group'
entry has no meaning of course.

[IP-HOMES]
This section lists all the IP numbers that Serv-U should  use
for multi-homed IP support. Each line couples an index number
with    a    corresponding   IP   number    of    the    form
'IPx=yyy.yyy.yyy.yyy'. In this 'x' is the index  number  (any
positive  number between 1 and 30000), and 'yyy.' is  the  IP
number that should be associated with it.

When  a user name should be coupled to a particular IP  home,
the  index  number for that IP home is appended to  the  user
name, preceded by a '@' character.

[RATIOS]
This is an auxiliary section for the use of UL/DL ratios.  It
allows  for  specifying a list of files which should  not  be
counted  by  the ratio system. Each line starts  with  'Free'
followed  by a sequential number. The information  after  the
equal  sign  is  the  path  or  file  name  that  should   be
discounted.

[EXTERNAL]
This  heading denotes a list of dynamic link libraries  which
Serv-U  should  use to very user access. In case  the  Serv-U
user  database does not provide an answer to access  requests
the  inquiry  is passed on to the first DLL in the  list,  if
this  DLL  does not have an answer it is send to  the  second
DLL, and so on.

Each   line  in  this  section  has  entries  of   the   form
'ClientCheckDLL'. These are followed by an order  number  and
specify the file name of the DLL to use. The DLL file  should
be  either in the Serv-U program directory, somewhere in  the
DOS path, or in the Windows directory for Serv-U to find it.

3.3 Using External User Access Verification DLLs
------------------------------------------------
Serv-U  can  use an external DLL to verify client access  and
retrieve information like a client's home directory  etc.  If
one  of  more  external DLLs are specified and Serv-U  cannot
find  the appropriate information internally it will question
each  of  the  external DLL's in turn. This can  be  used  to
create  an  interface to external user databases,  which  can
then  control FTP access. If the appropriate DLL exists,  for
example  the NT build-in user database could be  used,  or  a
Novell user database.

Setup
-----
To   make   Serv-U  use  external  DLLs  for  client   access
verification you need to add the DLL names to the  SERV-U.INI
file. At the moment there is no interactive user setup to  do
this, so the ini file has to be edited directly. There can be
more  than  one DLL, and Serv-U will query them in the  order
specified  until  one of the DLLs signals  that  it  had  the
required information.

The   DLL  names  need  to  be  added  to  a  section   named
'[EXTERNAL]'. The format is as follows (for example):

     [EXTERNAL]
     ClientCheckDLL1=CHKNOVELL.DLL
     ClientCheckDLL2=CHKNT.DLL
            .
            .

The  file names can be either full path names, or file  names
only.  If  the full path is specified then Serv-U  will  only
look at that path. If only the file name is given Serv-U will
first  look  in  the  program  directory,  then  the  current
directory,  the  entire  PATH, and  finally  in  the  Windows
directories.

DLL Specifications
------------------
The  DLL  entry  point for Serv-U needs to be  the  following
function:

     int HandleClientEvent(RClientEventStr* pEventStruc)

Please note that the function name is case sensitive!
The  function should return TRUE (=1) if it handled the event
and  does  not  want it to be passed on to the next  DLL.  It
should return FALSE (=0) in case it didn't handle the event.

The RClientEventStr structure is defined as follows:

     struct RClientEventStr {
       int Event;        // event code
       int  Flag;        // flag, meaning depends on event
       char User[40];    // user name
       char Aux[512];    //  auxiliary  area, usage depends on event
       char HostIP[16];  // server IP home
     }

The 'Event' code determines the nature of the request and can
have the following values:

     #define SRVU_LoginMesFile     1    // get login message file
     #define SRVU_HomeDir          2    // get home dir
     #define SRVU_Password         3    // verify password
     #define SRVU_IPAccess         4    // verify IP access
     #define SRVU_WriteFile        5    // verify write access
     #define SRVU_ReadFile         6    // verify read access
     #define SRVU_ModifyFile       7    // verify  mod./del. file access
     #define SRVU_ExecProg         8    // verify execute access
     #define SRVU_ListDir          9    // verify dir listing access
     #define SRVU_ChangeDir        10   // verify dir change access
     #define SRVU_DeleteDir        11   // verify dir delete access
     #define SRVU_CreateDir        12   // verify dir create access
     #define SRVU_HideHidden       13   // get setting for 'hide hidden files'
     #define SRVU_RelPaths         14   // get setting for 'relative paths'
     #define SRVU_RatioType        15   // get setting for type of ratios
     #define SRVU_RatioDown        16   // get setting for download ratio
     #define SRVU_RatioUp          17   // get setting for upload ratio
     #define SRVU_RatioCredit      18   // get/ajust ratio credit setting
     #define SRVU_RatioFree        19   // verify if file is free for ratios
     #define SRVU_QuotaEnable      20   // verify if disk quota is enabled
     #define SRVU_QuotaChange      21   // change in disk quota
     #define SRVU_QuotaMax         22   // maximum disk quota
     #define SRVU_AlwaysLogin      23   // allways allow login


Event Details
-------------
SRVU_LoginMesFile
       On entry:        User = user name
       On return:    Flag = TRUE (=1) if file name was found, FALSE (=0)
                   otherwise
             Aux = file name of login message file, if one was found

SRVU_HomeDir
       On entry:    User = user name
       On return:    Flag = TRUE if home dir was found, FALSE otherwise
             Aux = home dir (full path), if one was found

       Note:        In case a user account is disabled 'no home dir' should
            be returned.

SRVU_Password
       On entry:    User = user name
             Aux = password the user entered
       On return:    Flag = TRUE if password was correct, FALSE otherwise

SRVU_IPAccess
       On entry:    User = user name if available
             Aux = IP address of client, in text format
       On return:    Flag = TRUE if access is allowed, FALSE otherwise

       Note:        If no user name is present it means the client just
            connected and a check should be made for server-wide
            IP access. If a user name is present access should be
            checked for that particular user only.

SRVU_WriteFile
       On entry:    User = user name
             Aux = full path of file
       On return:    Flag = TRUE if access is allowed, FALSE otherwise

SRVU_ReadFile
       On entry:    User = user name
             Aux = full path of file
       On return:    Flag = TRUE if access is allowed, FALSE otherwise

SRVU_ModifyFile
       On entry:    User = user name
             Aux = full path of file
       On return:    Flag = TRUE if access is allowed, FALSE otherwise

SRVU_ExecProg
       On entry:    User = user name
             Aux = full path of program name to be executed
       On return:    Flag = TRUE if access is allowed, FALSE otherwise

SRVU_ListDir
       On entry:    User = user name
             Aux = full path of directory
       On return:    Flag = TRUE if access is allowed, FALSE otherwise

SRVU_ChangeDir
       On entry:    User = user name
             Aux = full path of directory
       On return:    Flag = TRUE if access is allowed, FALSE otherwise

SRVU_DeleteDir
       On entry:    User = user name
             Aux = full path of directory
       On return:    Flag = TRUE if access is allowed, FALSE otherwise

SRVU_CreateDir
       On entry:    User = user name
             Aux = full path of directory
       On return:    Flag = TRUE if access is allowed, FALSE otherwise

SRVU_HideHidden
       On entry:    User = user name

       On return:    Flag = TRUE if request was handled by DLL, FALSE otherwise
                    Aux = Aux[0]=1 if server should hide 'hidden' files
                               Aux[0]=0 if server should show 'hidden' files

SRVU_RelPaths
       On entry:    User = user name

       On return:    Flag = TRUE if request was handled by DLL, FALSE otherwise
                    Aux = Aux[0]=1 if server should use 'relative paths'
                               Aux[0]=0 for using full path names

SRVU_RatioType
       On entry:    User = user name

       On return:    Flag = TRUE if request was handled by DLL, FALSE otherwise
                   if U/D ratios should be disabled FALSE is also returned
                    Aux = set to the textual ratio type, as used in the INI file ie.
                                        "FilesPerSession" = count files for each session
                                          "BytesPerSession" = count bytes for each session
                                        "BytesOverall"    = count bytes over all sessions
                                        "FilesOverall"    = count files over all sessions

SRVU_RatioDown
       On entry:    User = user name

       On return:    Flag = TRUE if request was handled by DLL, FALSE otherwise
             Aux = set to the textual representation of the download ratio
                               (an unsigned 32-bit number)

SRVU_RatioUp
       On entry:    User = user name

       On return:    Flag = TRUE if request was handled by DLL, FALSE otherwise
             Aux = set to the textual representation of the upload ratio
                               (an unsigned 32-bit number)

SRVU_RatioCredit
       On entry:    User = user name
                    Aux = set to the textual representation of the value to add
                               to the credit (a floating point number, can be negative)
                               set to "0" if the request is to obtain the current value

       On return:    Flag = TRUE if request was handled by DLL, FALSE otherwise
             Aux = set to the textual representation of the (new) credit
                               value (a floating point number which can be negative)

       Note: All 'credit' calculations should be done with sufficient precision. In C
             a double is recommended.

SRVU_RatioFree
       On entry:    User = user name
                    Aux = set to the path/file name of the file to check if
                               it should be downloadable for free

       On return:    Flag = TRUE if file is free, otherwise FALSE

SRVU_QuotaEnable
       On entry:    User = user name

       On return:    Flag = TRUE if request was handled by DLL, FALSE otherwise
                    Aux = Aux[0]=1 if disk quota limitations are enabled
                               Aux[0]=0 if no disk quota limitations

SRVU_QuotaChange
       On entry:    User = user name
                    Aux = set to the textual representation of the value to change
                               the current quota with (can be negative, decreasing available
                               quota)
                               set to "0" if the request is to obtain the current value

       On return:    Flag = TRUE if request was handled by DLL, FALSE otherwise
             Aux = set to the textual representation of the (new) credit
                               value (a number which should always be positive).

SRVU_QuotaMax
       On entry:    User = user name

       On return:    Flag = TRUE if request was handled by DLL, FALSE otherwise
             Aux = set to the textual representation of the maximum
                               disk quota amount.

SRVU_AlwaysLogin
       On entry:    User = user name

       On return:    Flag = TRUE if request was handled by DLL, FALSE otherwise
                    Aux = Aux[0]=1 if user should always be allowed to log in
                               Aux[0]=0 if user should bounce if max. no. of users
                                        is reached


4. GETTING IN TOUCH - BUGS & REGISTRATION
=========================================

If  you  have questions or want to offer suggestions you  are
most  welcome  to drop me a line. However, please  check  out
this  manual and the Cat Soft Web site first to  see  if  the
answer to your question is already in there. Although I truly
love  to  hear  from  you and will do my best  to  help,  the
problem  is  that each day between 30 and 50 E-mail  messages
arrive  here,  and  you are talking to a one-man,  spare-time
company!  As it is I'm spending  2-3 hours a day on answering
E-mail  and  that is about as much as I have  to  spare.  The
easiest  way  to  get  in touch with me is  via  E-mail.  The
address is:

     [e-mail]

The Cat Soft Web site can be found at:

     http://www.cat-soft.com

Regular  mail  should  work as well, but  might  take  a  bit
longer. My address for this is:

     Rob Beckers
     210 Alexander Ave., Apt. D
     Durham, NC 27705
     USA


4.1 Serv-U Mailing List
-----------------------
There is also a WWW mailing list for Serv-U where you can ask
questions and discuss Serv-U related topics. To subscribe  to
the Serv-U mailing list, send an E-mail message to:

     [e-mail]

with  only  a  single line in the message body, which  should
read:

     subscribe Serv-U

This  will  return a message from the list manager  within  a
minute  or  so, explaining in detail how to post messages  to
the  list and related matters. I am also subscribed  to  this
list,  so each message you post will reach my E-mail  box  as
well.  When needed I'll respond to your message, but my  hope
is  that others will reply to, thus cutting down a bit on the
flood of messages I have to answer each day.

If  you want to look through previous postings to the mailing
list   (an  invaluable  source  of  information  for  solving
problems), please take a look at:

     http://www.pacemail.com/hyper/

4.2 Reporting Bugs
------------------
Nothing  in  this world is perfect, least of  all  me!  Alas,
chances are that despite careful testing you'll still find  a
bug.  Please don't think others will report it, let me  know!
There  are  a few things I need to know in order  to  improve
chances of fixing the beastie, so take note of the following:

   * Most  important: Can you get the same bug  to  appear  by
     repeating  certain actions? Please try hard;  without  a
     recipe  for repeating a bug, it's going to be very  hard
     to track it down.
   * What  TCP/IP  and WinSock stack are you using? Brand/type
     and  version  number please. What operating system  (DOS
     version  and Windows or Windows-For-Workgroups,  Windows
     95,  NT  version x.xx)? Any memory manager (QEMM  etc.),
     what version?
   * Please  indicate also if this bug is merely  cosmetic  or
     of  vital  importance  for using  Serv-U.  Somewhere  in
     between  is  possible as well of course. By the  way,  I
     consider security related bugs very important!
   * Finally,  please give me a chance to fix  a  bug,  before
     you  start to shout all over the Internet how  bad  this
     program is . . .

4.3 Registering Serv-U
----------------------
If  you're happy with the performance of Serv-U, then  please
make me happy and register this program! Just a few words for
those  who  are in doubt: Making this program took  me  (very
literally)  many  months of work, spread out  over  the  last
three years. Your registration fee is going to motivate me to
continue  improving  Serv-U.  In  general,  registration   is
important  for shareware programs: It makes it  possible  for
you to use professional quality software for peanuts. Lastly,
being  a  biomedical engineering graduate  student,  I'm  not
exactly making lots of $$'s (to put it mildly). So, those  25
bucks for registration mean a lot to me!

What  do  you  get if you register? As soon  as  I  get  your
registration   I'll  send  you  a  registration   code   plus
instructions  on  how  to add it to the  program.  This  will
enable  you  to  use  the program after the  30  day  try-out
period. Please let me know your E-mail address, since  Serv-U
is  tailored to pick the registration key out of  the  E-mail
message  I will send you. In case I have your E-mail  address
you'll  also  get  notified  when  there  are  updates.  Once
registered  you'll get those updates for free. That  is,  you
can use the same registration code on the updates, but you'll
have  to  get them yourself. Apart from all this you'll  also
get the nice, warm feeling of having contributed to improving
my earthly wealth!

The  registration code is tied to the user/company  name  you
specify on the registration form. You can see if your  server
is  registered  by  looking at the  'About'  dialog  box:  If
registered it will tell you to whom. Another thing to keep in
mind is that the registration information is sent back to any
FTP  client who uses the FTP command 'HELP'. This  is  not  a
much  used command but in principle it allows the whole world
to  find out who paid for your copy of Serv-U. If you're  the
lawful owner of the server this shouldn't bother you, if not.

The  registration fee is $25 for each copy. If  you  want  to
make  me  even happier and need several copies, the following
license prices apply:

     The FTP Serv-U license prices:

       1-9  $25 per copy

     License for:
       20   $250
       50   $500
       100  $700
       100+ $500 per block of 100 copies

     Licenses for more than 500 copies are negotiable.
     Educational discount: For licenses of 50 or more copies:
     30% discount.

The  'number of copies' in the above refers to the number  of
concurrently  running Serv-U FTP servers in your organization
(i.e.  it  is  independent of the number  of  concurrent  FTP
clients).  The  last page of this manual is the  registration
form. Please use this form for all registrations! That way  I
can keep my administration manageable.

4.4 Registration in the US
--------------------------
To   register  from  within  the  US,  please  fill  out  the
registration  form  and send it along  with  payment  to  the
address  on  the  form. A (personal) check made  out  to  Rob
Beckers is the preferred form of payment, but a Postal  Money
Order,  or  Purchase  Order is welcome too.  If  you  need  a
receipt,  then  please mention this on the registration  form
and I will send you one by paper mail. It is also possible to
register via CompuServe's SWREG service. The registration  ID
for  that  is  7743 and this costs $30 (Since CS  takes  $5).
Credit cards are welcome too! Accepted are Visa, Master Card,
Novus/Discovery, and American Express. I'm working on on-line
registration, but meanwhile you can either send me  the  card
number  and  expiration date by E-mail  (please  include  the
registration  form),  or drop me a line  asking  for  my  fax
number, so you can call the details in.

                       Important Note:
                       ===============
Make sure to include the registration form with whatever you
  send me!! I'm receiving way too many checks and purchase
orders without a form, often even without a name nor a phone
 number. If your order goes through a purchasing department
then please make sure they include the registration form with
                      the PO or check!

4.5 Registration from Abroad
----------------------------
While  borders are disappearing in many parts of  the  world,
getting  money across from one  country to another  is  still
not  easy, at least not when you want to keep the cost  down.
Below is a list of payment options that I accept (in order of
preference).  Please  make sure to include  the  registration
form with anything you send me.

By  far the easiest way to get money across the borders is by
credit card. Accepted are Visa, Master
Card,   Novus/Discovery   and   American   Express.   On-line
registration  is in the works, but meanwhile you  can  either
send me the card number and expiration date by E-mail (please
include the registration form), or drop me a line asking  for
my fax number, so you can call the details in.
Other payment options for registration from abroad are:

     * Using CompuServe's SWREG service. The registration ID
       for Serv-U is 7743 and registration costs $30 this way (CS
       takes $5, so I end up with $25).
     * By check, drawn at an American bank and in US dollars.
       The check should be made out to Rob Beckers.
     * By American Express Travelers Checks for the correct
       amount in US dollars. These are cheap and safe, but there
       might be a minimum commission charged by your bank. The
       checks should be made out to Rob Beckers and don't forget to
       sign them twice!
     * By Postal Money Order. As I understand it, you can buy
       these international money orders in most countries for very
       little money ($3 here in the US). Payment is in your own
       currency, but the money order should be made out for US $25
       and to Rob Beckers.
     * By cash, but only in US dollars and I give no guarantees
       about safe arrival! Please do not send me other currencies,
       it would probably cost me much more to convert them to US
       dollars than it will cost you. A trick I found useful for
       sending cash in envelopes: put the money in a folded sheet of
       paper so it doesn't shine through the envelope. This might
       improves chances of arrival considerably.
     * For the Dutch: Het is ook mogelijk te betalen door fl.
       40 over te maken op girorekening 53.95.461 t.n.v. Rob Beckers
       te Bunde. Stuur dan wel even het registratie formulier per E-
       mail  naar mij toe. S.v.p. geen geld vanuit Belgie  of
       Duitsland rechtstreeks overmaken, want daarvan blijft niet
       veel over!
     * For Canadians only: By any type of (personal) bank check
       of Canada. Just make the check out in US dollars. Doing so is
       easy: Write "US" in front of the dollar sign and add "US
       Funds" below the sum. This way neither of us pays anything
       extra (I don't, and as far as I know you don't either, but
       check with your bank if you want to make sure). The check
       should be made out to Rob Beckers.
     * By direct money transfer in US dollars to my American
       bank account. Please add $13 extra, since that is the fee my
       bank charges me to receive money this way. Please send me the
       registration form by E-mail in this case. The details for a
       wire transfer are:

          Bank:
               Wachovia
               Durham - North Carolina
          ABA/Routing no:
               053100494
          Account:
               No. 2373193064
               Rob Beckers
               210 Alexander Ave., Apt. D
               Durham, NC 27705
               USA


******************** REGISTRATION FORM **********************

ROB BECKERS
210 Alexander Ave., Apt. D
Durham, NC 27705
U.S.A.



                     REGISTRATION FORM SERV-U
                     ========================


           Name: ............................................

   Company Name: ............................................

        Address: ............................................

                 ............................................

                 ............................................

   Phone Number: ............................................

 E-Mail Address: ............................................
                  (Important! Reg. Code is sent by E-mail)
  No. of copies: .........

Additional comments, suggestions, complaints, praise, etc .

.............................................................

.............................................................

.............................................................

Registration fee is $25 per copy. Send this order form  along
with your payment to: Rob Beckers, 210 Alexander Ave. Apt. D,
Durham NC 27705, USA.

If   you  have any questions, comments or suggestions  please
contact  Rob  Beckers at the above address or via  e-mail  to
[e-mail]. Check out the site license prices in  the
manual if you need multiple copies.

As  this software is shareware it comes `as is', there is  no
warranty  implied  or  otherwise, nor  is  support  provided.
However, if you discover any bugs or problems please  contact
the developer at the above e-mail address.