Il CD di internet/CD.iso/HOWTO/ETHERNET

Text File | 1995-04-20 | 139.7 KB | 3,759 lines

  Linux    Ethernet-Howto
  Paul Gortmaker, Editor.
  v2.3,    11/02/95

  This is the Ethernet-Howto, which is a compilation of    information
  about    which ethernet devices can be used for Linux, and how to set
  them up. It hopefully    answers    all the    frequently asked questions about
  using    ethernet cards with Linux. Note    that this Howto    is focused on
  the hardware and low level driver aspect of the ethernet cards, and
  does not cover the software end of things. See the NET2-Howto    for that
  stuff.

  1.  Introduction


  The Ethernet-Howto covers what cards you should and shouldn't    buy; how
  to set them up, how to run more than one, and    other common problems
  and questions. It contains detailed information on the current level
  of support for all of    the most common    ethernet cards available.  It
  does not cover the software end of things, as    that is    covered    in the
  NET-2    Howto. Also note that general non-Linux    specific questions about
  Ethernet are not (or at least    they should not    be) answered here. For
  those    types of questions, see    the excellent amount of    information in
  the comp.dcom.lans.ethernet FAQ. You can FTP it from dorm.rutgers.edu
  in the directory /pub/novell/info_and_docs/

  This present revision    covers kernels up to and including v1.1.91

  The Ethernet-Howto is    edited and maintained by:

       Paul Gortmaker, [e-mail]


  The primary source of    the information    for the    Ethernet-Howto is from:

       Donald J. Becker, [e-mail]


  who we have to thank for writing the vast majority of    ethernet card
  drivers that are presently available for Linux. He also is the
  original author of the NFS server too. Thanks    Donald!    We owe ya one!
  :-)

  Net-surfers may wish to check    out the    following URL:

  Donald Becker
  (http://cesdis.gsfc.nasa.gov/pub/people/becker/whoiam.html)


  1.1.    Using the Ethernet-Howto


  As this guide    is getting bigger and bigger, you probably don't want to
  spend    the rest of your afternoon reading the whole thing. And    you
  don't    have to    read it    all. If    you haven't got    an ethernet card, then
  you will want    to start with ``What card should I buy...''  to    see what
  you should buy, and what you should avoid. If    you have already got an
  ethernet card, but are not sure if you can use it with Linux,    then you
  will want to read ``Vendor Specific...''  which contains specific
  information on each manufacturer, and    their cards. If    you are    having
  trouble with your card, then you will    want to    read the specific
  information about your card mentioned    above, and the troubleshooting
  information in ``the FAQ section''.  If you are interested in    some of
  the technical    aspects    of the device drivers, then you    can find that
  information in ``Technical Information''

  1.2.    Disclaimer and Copyright


  This document    is not gospel. However,    it is probably the most    up to
  date info that you will be able to find. Nobody is responsible for
  what happens to your hardware    but yourself. If your ethercard    or any
  other    hardware goes up in smoke (...nearly impossible!)  we take no
  responsibility. ie. THE AUTHORS ARE NOT RESPONSIBLE FOR ANY DAMAGES
  INCURRED DUE TO ACTIONS TAKEN    BASED ON THE INFORMATION INCLUDED IN
  THIS DOCUMENT.

  This document    is Copyright (c) 1994 by Donald    Becker and Paul
  Gortmaker. Permission    is granted to make and distribute verbatim
  copies of this manual    provided the copyright notice and this
  permission notice are    preserved on all copies.

  Permission is    granted    to copy    and distribute modified    versions of this
  document under the conditions    for verbatim copying, provided that this
  copyright notice is included exactly as in the original, and that the
  entire resulting derived work    is distributed under the terms of a
  permission notice identical to this one.

  Permission is    granted    to copy    and distribute translations of this
  document into    another    language, under    the above conditions for
  modified versions.

  If you are intending to incorporate this document into a published
  work,    please contact me, and I will make an effort to    ensure that you
  have the most    up to date information available. In the past, out of
  date versions    of the Linux howto documents have been published, which
  caused the developers    undue grief from being plagued with questions
  that were already answered in    the up to date versions.


  1.3.    Mailing    Lists and the Linux Newsgroups



  If you have questions    about your ethernet card, please READ this
  document first. You may also want to join the    NET channel of the
  Linux-activists mailing list by sending mail to

       [e-mail]


  with the line

       X-Mn-Admin: join    NET


  at the top of    the message body (not the subject). If you want    to learn
  how to use the mailing channels, then    send an    empty message to the
  above    address, and you will get an instruction manual    sent back to you
  in a few hours. However, it is worth noting that the NET channel is
  primarily used for discussion    of the networking code,    and you    may not
  see much discussion about a particular driver.

  Furthermore keep in mind that    the NET    channel    is for development
  discussions only. General questions on how to    configure your system
  should be directed to    comp.os.linux.help unless you are actively
  involved in the development of part of the networking    for Linux.  We
  ask that you please respect this general guideline for content.

  Recently, a similar group of mailing lists has started on the    host
  vger.rutgers.edu, using the much more    common majordomo mailing list
  server. Send mail to [e-mail] to get help with what
  lists    are available, and how to join them.

  Also,    the news groups    comp.sys.ibm.pc.hardware.networking and
  comp.dcom.lans.ethernet should be used for questions that are    not
  Linux    specific.


  1.4.    Related    Documentation


  Much of this info came from saved postings from the comp.os.linux
  groups, which    shows that it is a valuable resource of    information.
  Other    useful information came    from a bunch of    small files by Donald
  himself. Of course, if you are setting up an Ethernet    card, then you
  will want to read the    NET-2 Howto so that you    can actually configure
  the software you will    use.  And last but not least, the contributions
  from the individuals and companies listed in ``Contributors''    is
  greatly appreciated as well. Oh yeah,    if you fancy yourself as a bit
  of a hacker, you can always scrounge some additional info from the
  driver source    files as well. There is    usually    a paragraph in there
  describing any important points.

  For those looking for    information that is not    specific in any    way to
  Linux    (i.e. what is 10BaseT, what is AUI, what does a    hub do,    etc.)  I
  strongly recommend the Ethernet-FAQ from the newsgroup
  comp.dcom.lans.ethernet. Look    on the FTP site    dorm.rutgers.edu in the
  directory /pub/novell/info_and_docs/ or grab it from the following
  URL:

  Ethernet FAQ
  (ftp://dorm.rutgers.edu/pub/novell/info_and_docs/Ethernet.FAQ)

  Don't    let the    fact that it was last revised in 1993 scare you, as not
  much has happened to Ethernet    since then. (Discounting the upcoming
  100Base-whatever, of course.)


  1.5.    New Versions of    this Document


  New versions of this document    can be retrieved via anonymous FTP from
  sunsite.unc.edu, in /pub/Linux/docs/HOWTO/* and various Linux    ftp
  mirror sites.    Updates    will be    made as    new information    / drivers
  becomes available. If    this copy that you are reading is more than 2
  months old, it is either out of date,    or it means that I have    been
  lazy and haven't updated it.    This document was produced by using the
  SGML system that was specifically set    up for the Linux Howto project,
  and there are    various    output formats available, including, postscript,
  dvi, ascii, html, and    soon TeXinfo.

  I would recommend viewing it in the html (via    Mosaic)    or the
  Postscript/dvi format. Both of these contain cross-references    that are
  lost in the ascii translation.

  If you want to get the official copy off sunsite, here is URL.

  Ethernet-HOWTO (http://sunsite.unc.edu/mdw/HOWTO/Ethernet-HOWTO.html)

  If minor additions and changes have been made, you can view the latest
  working copy from this URL.

  Working Copy (http://rsphy1.anu.edu.au/~gpg109/Ethernet-HOWTO.html)




  2.  What card    should I buy for Linux?


  For impatient    users that just    want a quick, cheap answer the summary
  is: get 16 bit thinnet 8013 cards. For those who want    the absolute
  best performance, get    an AMD PC-Net/Lance based card.    For more detail
  as to    the who    what where and why, read on.


  2.1.    Eight bit vs 16    bit


  Unless you are a light user, or are confined to using    the smaller ISA
  slot,    the use    of the 8 bit cards like    the wd8003, the    3c503 and the
  ne1000 is usually not    worth the cost savings.    Get the    8013 or    the
  3c503/16, or the ne2000 instead. (The    3c501 is not included in this
  discussion, as it shouldn't be used under any    circumstances.)

  However, so not to leave you with a bad taste    in your    mouth if you
  happen to already have one, you can still expect to get about    500kB/s
  ftp download speed to    an 8 bit wd8003    card (on a 16MHz ISA bus) from a
  fast host.  And if most of your net-traffic is going to remote sites,
  then the bottleneck in the path will be elsewhere, and the only speed
  difference you will notice is    during net activity on your local
  subnet.

  A note to NFS    users: Some people have    found that using 8 bit cards in
  NFS clients causes poorer than expected performance, when using 8kB
  (native Sun) NFS packet size.

  The possible reason for this could be    due to the difference in on
  board    buffer size between the    8 bit and the 16 bit cards.  The 8 bit
  cards    have an    8kB buffer, and    the 16 bit cards have a    16kB buffer. The
  Linux    driver will reserve 3kB    of that    buffer (for Tx ping-pong
  buffers), leaving only 5kB for an 8 bit card.    The maximum ethernet
  packet size is about 1500 bytes. Now that 8kB    NFS packet will    arrive
  as about 6 back to back maximum size ethernet    packets. Both the 8 and
  16 bit cards have no problem Rx'ing back to back packets. The    problem
  arises when the machine doesn't remove the packets from the cards
  buffer in time, and the buffer overflows. The    fact that 8 bit    cards
  take an extra    ISA bus    cycle per transfer doesn't help    either.    What you
  can do if you    have an    8 bit card is either set the NFS transfer size
  to 4kB, or try increasing the    ISA bus    speed in order to get the card's
  buffer cleared out faster.


  2.2.    Low price Ethernet cards


  The lowest price seen    so far was in the March    '94 edition of LAN
  magazine. There was an ad for    Addtron    AE-200 cards (jumper settable
  NE2000 clones) for a measly $19 ea!  Unfortunately this offer    has
  since    expired. However, you might want to check to see what their
  everyday price is.

  You can also call AT-LAN-TEC at 301-948-7070.    Ask for    their technical
  support person. As with all purchases, you should indicate you are
  buying this for a Linux system.  NB: Their current NE2000 clone is a
  model    that `traps' other drivers that    probe into their address space.
  AT-LAN-TEC also carries a clone, non-EEPROM 8013 board for somewhat
  more,    and a NE2100 clone.  Either is a better    choice if the very
  lowest price isn't essential.

  And a    recent addition    is the VLB and PCI cards offered by Boca
  Research. These are selling for around the $70 mark, and these are
  supported with the latest kernel. These use the new 32 bit versions of
  the LANCE chip from AMD. See ``Boca Research'' for more info.

  If you require an ISA    card, you can use the the Allied Telesis AT1500
  which    uses the ISA version of    the LANCE chip from AMD.  It is    offered
  at a good price by many vendors.  Even Inmac,    known for their    premium
  markup, has this card    for under $100.    See ``AT-1500''    for more info.



  2.3.    Vendors    and Brands to Avoid


  These    vendors    have decided not to release programming    information
  about    their products,    without    signing    a NDA (non-disclosure
  agreement).  Hence it    is strongly advised that you avoid buying
  products offered from    these companies.

  (1) Cabletron    (see ``Cabletron'')

  (2) Xircom (see ``Xircom'')

  These    particular cards should    be avoided, as they are    obsolete.  The
  reasons as to    why they have been classified as such can be found in
  their    respective sections. For your particular application, these
  reasons may not be a concern,    so you should have a read of the reasons
  listed.

  (1) 3c501 (see ``3Com    3c501'')

  (2) Arcnet based cards (see ``Arcnet'')

  (3) Any 8-bit    cards (see ``Eight bit...'')


  2.4.    Type of    cable that your    card should support


  Unless you have to conform to    an existing network, you will want to
  use thinnet or thin ethernet cable. This is the style    with the
  standard BNC connectors. See ``Cables, Coax...''  for    other concerns
  with different types of ethernet cable.

  Most ethercards also come in a `Combo' version for only $10-$20 more.
  These    have both twisted pair and thinnet transceiver built-in,
  allowing you to change your mind later.

  The twisted pair cables, with    the RJ-45 (giant phone jack) connectors
  is technically called    10BaseT. You may also hear it called UTP
  (Unsheilded Twisted Pair).

  The thinnet, or thin ethernet    cabling, (RG-58    coaxial    cable) with the
  BNC (metal push and turn-to-lock) connectors is technically called
  10Base2.

  The older thick ethernet (10mm coaxial cable)    which is only found in
  older    installations is called    10Base5.

  Large    corporate installations    will most likely use 10BaseT instead of
  10Base2. 10Base2 does    not offer an easy upgrade path to the new
  upcoming 100Base-whatever.


  3.  Vendor/Manufacturer/Model    Specific Information



  The only thing that one needs    to use an ethernet card    with Linux is
  the appropriate driver. For this, it is essential that the
  manufacturer will release the    technical programming information to the
  general public without you (or anyone) having    to sign    your life away.
  A good guide for the likelihood of getting documentation (or,    if you
  aren't writing code, the likelihood that someone else    will write that
  driver you really, really need) is the availability of the Crynwr (nee
  Clarkson) packet driver. Russ    Nelson runs this operation, and    has been
  very helpful in supporting the development of    drivers    for Linux. Net-
  surfers can try this URL to look up Russ' software.

  Russ Nelson's    Packet Drivers (http://www.crynwr.com/crynwr/home.html)

  Given    the documentation, you can write a driver for your card    and use
  it for Linux (at least in theory) and    if you intend to write a driver,
  have a look at ``Skeleton driver'' as    well.  Keep in mind that some
  old hardware that was    designed for XT    type machines will not function
  very well in a multitasking environment such as Linux. Use of    these
  will lead to major problems if your network sees a reasonable    amount
  of traffic.

  Most cards come with drivers for MS-DOS interfaces such as NDIS and
  ODI, but these are useless for Linux.    Many people have suggested
  directly linking them    in or automatic    translation, but this is nearly
  impossible. The MS-DOS drivers expect    to be in 16 bit    mode and hook
  into `software interrupts', both incompatible    with the Linux kernel.
  This incompatibility is actually a feature, as some Linux drivers are
  considerably better than their MS-DOS    counterparts. The `8390' series
  drivers, for instance, use ping-pong transmit    buffers, which are only
  now being introduced in the MS-DOS world.

  Keep in mind that PC ethercards have the widest variety of interfaces
  (shared memory, programmed I/O, bus-master, or slave DMA) of any
  computer hardware for    anything, and supporting a new ethercard
  sometimes requires re-thinking most of the lower-level networking
  code.    (If you    are interested in learning more    about these different
  forms    of interfaces, see ``Programmed    I/O vs.    ...''.)

  Also,    similar    product    numbers    don't always indicate similar products.
  For instance,    the 3c50* product line from 3Com varies    wildly between
  different members.

  Enough talk. Let's get down to the information you want.


  3.1.    3Com


  If you are not sure what your    card is, but you think it is a 3Com
  card,    you can    probably figure    it out from the    assembly number. 3Com
  has a    document `Identifying 3Com Adapters By Assembly    Number'    (ref
  24500002) that would most likely clear things    up. See    ``Technical
  Information from 3Com'' for info on how to get documents from    3Com.

  Also note that 3Com has a FTP    site with various goodies: ftp.3Com.com
  that you may want to check out.


  3.1.1.  3c501


  Status -- Semi-Supported

  Too brain-damaged to use. Available surplus from many    places.    Avoid it
  like the plague. Again, do not purchase this card, even as a joke.
  It's performance is horrible,    and it breaks in many ways.
  Cameron L. Spitzer of    3Com said: ``I'm speaking only for myself here,
  of course, but I believe 3Com    advises    against    installing a 3C501 in a
  new system, mostly for the same reasons Donald has discussed.    You
  probably won't be happy with the 3C501 in your Linux box. The    data
  sheet    is marked `(obsolete)' on 3Com's Developers' Order Form, and the
  board    is not part of 3Com's program for sending free Technical
  Reference Manuals to people who need them. The decade-old things are
  nearly indestructible, but that's about all they've got going    for them
  any more.''

  For those not    yet convinced, the 3c501 can only do one thing at a time
  -- while you are removing one    packet from the    single-packet buffer it
  cannot receive another packet, nor can it receive a packet while
  loading a transmit packet. This was fine for a network between two
  8088-based computers where processing    each packet and    replying took
  10's of msecs, but modern networks send back-to-back packets for
  almost every transaction.

  Donald writes: `The driver is    now in the std.    kernel,    but under the
  following conditions:    This is    unsupported code. I know the usual
  copyright says all the code is unsupported, but this is _really_
  unsupported. I DON'T want to see bug reports,    and I'll accept    bug
  fixes    only if    I'm in a good mood that    day.

  I don't want to be flamed later for putting out bad software.    I don't
  know all all of the 3c501 bugs, and I    know this driver only handles a
  few that I've    been able to figure out. It has    taken a    long intense
  effort just to get the driver    working    this well.'

  AutoIRQ works, DMA isn't used, the autoprobe only looks at 0x280 and
  0x300, and the debug level is    set with the third boot-time argument.

  Once again, the use of a 3c501 is strongly discouraged!  Even    more so
  with a IP multicast kernel, as you will grind    to a halt while
  listening to all multicast packets. See the comments at the top of the
  source code for more details.


  3.1.2.  3c503, 3c503/16


  Status -- Supported

  3Com shared-memory ethercards. They also have    a programmed I/O mode
  that doesn't use the 8390 facilities (their engineers    found too many
  bugs!)  It should be about the same speed as the same    bus width
  WD80x3, Unless you are a light user, spend the extra money and get the
  16 bit model,    as the price difference    isn't significant. The 3c503
  does not have    ``EEPROM setup'', so the diagnostic/setup program isn't
  needed before    running    the card with Linux. The shared    memory address
  of the 3c503 is set using jumpers that are shared with the boot PROM
  address. This    is confusing to    people familiar    with other ISA cards,
  where    you always leave the jumper set    to ``disable'' unless you have a
  boot PROM.

  The Linux 3c503 driver can also work with the    3c503 programmed-I/O
  mode,    but this is slower and less reliable than shared memory    mode.
  Also,    programmed-I/O mode is not tested when updating    the drivers, the
  deadman (deadcard?) check code may falsely timeout on    some machines,
  and the probe    for a 3c503 in programmed-I/O mode is turned off by
  default in some versions of the kernel. This was a panic reaction to
  the general device driver probe explosion; the 3c503 shared memory
  probe    is a safe read from memory, rather than    an extensive scan
  through I/O space. As    of 0.99pl13, the kernel    has an I/O port
  registrar that makes I/O space probes    safer, and the programmed-I/O
  3c503    probe has been re-enabled.  You    still shouldn't    use the
  programmed-I/O mode though, unless you need it for MS-DOS
  compatibility.

  The 3c503's IRQ line is set in software, with    no hints from an EEPROM.
  Unlike the MS-DOS drivers, the Linux driver has capability to    autoIRQ:
  it uses the first available IRQ line in {5,2/9,3,4}, selected    each
  time the card    is ifconfig'ed.    (Older driver versions selected    the IRQ
  at boot time.) The ioctl() call in `ifconfig'    will return EAGAIN if no
  IRQ line is available    at that    time.

  Some common problems that people have    with the 503 are discussed in
  ``Problems with...''.



  3.1.3.  3c505


  Status -- Semi-Supported

  This is a driver that    was written by Craig Southeren
  [e-mail]. These cards also use the i82586 chip.  I
  don't    think there are    that many of these cards about.     It is included
  in the standard kernel, but it is classed as an alpha    driver.    See
  ``Alpha Drivers'' for    important information on using alpha-test
  ethernet drivers with    Linux.

  There    is also    the file /usr/src/linux/drivers/net/README.3c505 that
  you should read if you are going to use one of these cards.  It
  contains various options that    you can    enable/disable.     Technical
  information is available in ``Programming the    Intel chips''.


  3.1.4.  3c507

  Status -- Semi-Supported

  This card uses one of    the Intel chips, and the development of    the
  driver is closely related to the development of the Intel Ether
  Express driver.  The driver is included in the standard kernel
  release, but as an alpha driver.

  See ``Alpha Drivers''    for important information on using alpha-test
  ethernet drivers with    Linux. Technical information is    available in
  ``Programming    the Intel chips''.


  3.1.5.  3c509    / 3c509B


  Status -- Supported

  It's fairly inexpensive and has excellent performance    for a non-bus-
  master design.  The drawbacks    are that the original 3c509 _requires_
  very low interrupt latency. The 3c509B shouldn't suffer from the same
  problem, due to having a larger buffer. (See below.)

  Note that the    ISA card detection uses    a different method than    most
  cards. Basically, you    ask the    cards to respond by sending data to an
  ID_PORT (port    0x100).    Note that if you have some other strange ISA
  card using an    I/O range that includes    the ID_PORT of the 3c509, it
  will probably    not get    detected. Note that you    can change the ID_PORT
  to 0x110 or 0x120 or... in 3c509.c if    you have a conflicting ISA card,
  and the 3c509    will still be happy.  Also note    that this detection
  method means that it is difficult to predict which card will get
  detected first in a multiple ISA 3c509 configuration.     The card with
  the lowest hardware ethernet address will end    up being eth0. This
  shouldn't matter to anyone, except for those people who want to assign
  a 6 byte hardware address to a particular interface.

  A working 3c509 driver was first included as an alpha-test version in
  the 0.99pl13 kernel sources.    It is now in the standard kernel.

  The original 3c509 has a tiny    Rx buffer (2kB), causing the driver to
  occasionally drop a packet if    interrupts are masked for too long. To
  minimize this    problem, you can try unmasking interrupts during IDE
  disk transfers (see hdparm(8)) and/or    increasing your    ISA bus    speed so
  IDE transfers    finish sooner.    (Note that the driver could be
  completely rewritten to use predictive interrupts, but performance re-
  writes of working drivers are    low priority unless there is some
  particular incentive or need.)

  The newer model 3c509B has 8kB on board, and the driver can set 4, 5
  or 6kB for an    Rx buffer. This    setting    can also be stored on the
  EEPROM. This should alleviate    the above problem with the original
  3c509. At this point in time,    the Linux driver is not    aware of this,
  and treats the 3c509B    as an older 3c509.

  Apparently, 3c509B users may have to use the supplied    DOS utility to
  disable the plug and play support, and to set    the output media to what
  they require.

  Cameron Spitzer writes: ``Beware that    if you put a '509 in EISA
  addressing mode by mistake and save that in the EEPROM, you'll have to
  use an EISA machine or the infamous Test Via to get it back to normal,
  and it will conflict at IO location 0    which may hang your ISA    machine.
  I believe this problem is corrected in the 3C509B version of the
  board.''


  3.1.6.  3c523


  Status -- Not    Supported

  This MCA bus card uses the i82586, and now that people are actually
  running Linux    on MCA machines, someone may wish to try and recycle
  parts    of the 3c507 driver into a driver for this card.


  3.1.7.  3c527


  Status -- Not    Supported

  Yes, another MCA card. No, not too much interest in it.  Better
  chances with the 3c523 or the    3c529.


  3.1.8.  3c529


  Status -- Not    Supported

  This card actually uses the same chipset as the 3c509.  Donald
  actually put hooks into the 3c509 driver to check for    MCA cards after
  probing for EISA cards, and before probing for ISA cards. But    it
  hasn't evolved much further than that. Donald    writes:

  ``I don't have access    to a MCA machine (nor do I fully understand the
  probing code)    so I never wrote the mca_adaptor_select_mode() or
  mca_adaptor_id() routines. If    you can    find a way to get the adaptor
  I/O address that assigned at boot time, you can just hard-wire that in
  place    of the commented-out probe. Be sure to keep the    code that reads
  the IRQ, if_port, and    ethernet address.''

  3.1.9.  3c579


  Status -- Supported

  The EISA version of the 509. The current EISA    version    uses the same 16
  bit wide chip    rather than a 32 bit interface,    so the performance
  increase isn't stunning.  The    EISA probe code    was added to 3c509.c for
  0.99pl14.  We    would be interested in hearing progress    reports    from any
  3c579    users. (Read the above 3c509 section for info on the driver.)

  Cameron Spitzer writes: ``The    3C579 (Etherlink III EISA) should be
  configured as    an EISA    card. The IO Base Address (window 0 register 6
  bits 4:0) should be 1f, which    selects    EISA addressing    mode. Logic
  outside the ASIC decodes the IO address s000,    where s    is the slot
  number. I don't think    it was documented real well. Except for    its IO
  Base Address,    the '579 should    behave EXACTLY like the'509 (EL3 ISA),
  and if it doesn't, I want to hear about it (at my work address).''



  3.1.10.  3c589 / 3c589B


  Status -- Semi-Supported

  Many people have been    using this PCMCIA card for quite some time now.
  Note that support for    it is not (at present) included    in the default
  kernel source    tree. Note that    you will need a    supported PCMCIA
  controller chipset. There are    drivers    available on Donald's ftp site:


       cesdis.gsfc.nasa.gov:/pub/linux/pcmcia/README.3c589 ces-
       dis.gsfc.nasa.gov:/pub/linux/pcmcia/3c589.c ces-
       dis.gsfc.nasa.gov:/pub/linux/pcmcia/dbether.c


  Or for those that are    net-surfing you    can try:

  Don's    PCMCIA Stuff (http://cesdis.gsfc.nasa.gov/linux/pcmcia.html)

  You will still need a    PCMCIA socket enabler as well.

  See ``PCMCIA Support'' for more info on PCMCIA chipsets, socket
  enablers, etc.

  The "B" in the name means the    same here as it    does for the 3c509 case.


  3.2.    Accton



  3.2.1.  Accton MPX


  Status -- Supported

  Don't    let the    name fool you. This is still supposed to be a NE2000
  compatible card. The MPX is supposed to stand    for MultiPacket
  Accelerator, which, according    to Accton, increases throughput
  substantially. But if    you are    already    sending    back-to-back packets,
  how can you get any faster...


  3.2.2.  Accton EN2212    PCMCIA Card


  Status -- Semi-Supported

  David    Hinds has been working on a driver for this card, and you are
  best to check    the latest release of his PCMCIA package to see    what the
  present status is.


  3.3.    Allied Telesis



  3.3.1.  AT1500


  Status --Supported

  These    are a series of    low-cost ethercards using the 79C960 version of
  the AMD LANCE. These are bus-master cards, and thus probably the
  fastest ISA bus ethercards available (although the 3c509 has lower
  latency thanks to predictive interrupts).

  DMA selection    and chip numbering information can be found in ``AMD
  LANCE''.

  More technical information on    AMD LANCE based    Ethernet cards can be
  found    in ``Notes on AMD...''.


  3.3.2.  AT1700


  Status -- Supported

  The Allied Telesis AT1700 series ethercards are based    on the Fujitsu
  MB86965. This    chip uses a programmed I/O interface, and a pair of
  fixed-size transmit buffers. This allows small groups    of packets to
  sent be sent back-to-back, with a short pause    while switching    buffers.

  A unique feature is the ability to drive 150ohm STP (Shielded    Twisted
  Pair)    cable commonly installed for Token Ring, in addition to    10baseT
  100ohm UTP (unshielded twisted pair).

  The Fujitsu chip used    on the AT1700 has a design flaw: it can    only be
  fully    reset by doing a power cycle of    the machine.  Pressing the reset
  button doesn't reset the bus interface. This wouldn't    be so bad,
  except that it can only be reliably detected when it has been    freshly
  reset. The solution/work-around is to    power-cycle the    machine    if the
  kernel has a problem detecting the AT1700.

  Some production runs of the AT1700 had another problem: they are
  permanently wired to DMA channel 5.  This is undocumented, there are
  no jumpers to    disable    the "feature", and no driver dares use the DMA
  capability because of    compatibility problems.    No device driver will be
  written using    DMA if installing a second card    into the machine breaks
  both,    and the    only way to disable the    DMA is with a knife.

  The at1700 driver is included    in the standard    kernel source tree.



  3.4.    AMD / Advanced Micro Devices



  3.4.1.  AMD LANCE (7990, 79C960, PCnet-ISA)


  Status -- Supported

  There    really is no AMD ethernet card.    You are    probably reading this
  because the only markings you    could find on your card    said AMD and the
  above    number.    The 7990 is the    original `LANCE' chip, but most    stuff
  (including this document) refer to all these similar chips as    `LANCE'
  chips. (...incorrectly, I might add.)

  These    above numbers refer to chips from AMD that are the heart of many
  ethernet cards.  For example,    the Allied Telesis AT1500 (see
  ``AT1500'') the NE1500/2100 (see ``NE1500'') and the Boca-VLB/PCI
  cards    (see ``Boca-VLB/PCI'')

  The 79C960 (a.k.a. PCnet-ISA)    contains enhancements and bug fixes over
  the original 7990 LANCE design.

  Chances are that the existing    LANCE driver will work with all    AMD
  LANCE    based cards. (except perhaps the NI65XX    - see ``NI65XX'' for
  more info on that one.)  This    driver should also work    with NE1500 and
  NE2100 clones.

  For the ISA bus master mode all structures used directly by the LANCE,
  the initialization block, Rx and Tx rings, and data buffers, must be
  accessible from the ISA bus, i.e. in the lower 16M of    real memory.  If
  more than 16MB of memory is installed, low-memory `bounce-buffers' are
  used when needed.

  The DMA channel can be set with the low bits of the otherwise-unused
  dev->mem_start value (a.k.a. PARAM_1).  (see ``PARAM_1'') If unset it
  is probed for    by enabling each free DMA channel in turn and checking
  if initialization succeeds.

  The HP-J2405A    board is an exception: with this board it's easy to read
  the EEPROM-set values    for the    IRQ, and DMA.

  See ``Notes on AMD...''  for more info on these chips.


  3.4.2.  AMD 79C961 (PCnet-ISA+)


  Status -- Supported

  This is the PCnet-ISA+  -- an    enhanced version of the    79C960.     It has
  support for jumper-less configuration    and Plug and Play.  See    the info
  in the above section.


  3.4.3.  AMD 79C965 (PCnet-32)


  Status -- Supported

  This is the PCnet-32 -- a 32 bit bus-master version of the original
  LANCE    chip for VL-bus    and local bus systems.    Minor cleanups were
  added    to the original    lance driver around v1.1.50 to support these 32
  bit versions of the LANCE chip.  The main problem was    that the current
  versions of the '965 and '970    chips have a minor bug.     They clear the
  Rx buffer length field in the    Rx ring    when they are explicitly
  documented not to. Again, see    the above info.


  3.4.4.  AMD 79C970 (PCnet-PCI)


  Status -- Supported

  This is the PCnet-PCI    -- similar to the PCnet-32, but    designed for PCI
  bus based systems. Again, see    the above info.     Donald    has modified the
  LANCE    driver to use the PCI BIOS structure that was introduced by Drew
  Eckhardt for the PCI-NCR SCSI    driver.    This means that    you need to
  build    a kernel with PCI BIOS support enabled.


  3.4.5.  AMD 79C974 (PCnet-SCSI)


  Status -- Supported

  This is the PCnet-SCSI --  which is basically    treated    like a '970 from
  an Ethernet point of view. A minor '974 specific fix was added to the
  1.1.8x kernels, so get a 1.1.90 or newer kernel. Also    see the    above
  info.    Don't ask if the SCSI half of the chip is supported -- this is
  the Ethernet-Howto, not the SCSI-Howto.


  3.5.    Ansel Communications



  3.5.1.  AC3200 EISA


  Status -- Semi-Supported

  This driver is included in the present kernel    as an alpha test driver.
  Please see ``Alpha Drivers'' in this document    for important
  information regarding    alpha drivers.    If you use it, let Donald know
  how things work out, as not too many people have this    card and
  feedback has been low.


  3.6.    Apricot



  3.6.1.  Apricot Xen-II On Board Ethernet


  Status -- Supported

  This on board    ethernet uses an i82596    bus-master chip.  It can only be
  at i/o address 0x300.    The author of this driver is Mark Evans. By
  looking at the driver    source,    it appears that    the IRQ    is hardwired to
  10.

  Earlier versions of the driver had a tendency    to think that anything
  living at 0x300 was an apricot NIC.  Since then the hardware address
  is checked to    avoid these false detections.


  3.7.    Arcnet



  Status -- Semi-Supported

  With the very    low cost and better performance    of ethernet, chances are
  that most places will    be giving away their Arcnet hardware for free,
  resulting in a lot of    home systems with Arcnet.

  An advantage of Arcnet is that all of    the cards have identical
  interfaces, so one driver will work for everyone.

  Recent interest in getting Arcnet going has picked up    again and Avery
  Pennarun's alpha driver has been put into the    default    kernel sources
  for 1.1.80 and above.    The arcnet driver uses `arc0' as its name
  instead of the usual `eth0' for ethernet devices.  Bug reports and
  success stories can be mailed    to:

  [e-mail]


  3.8.    AT&T


  Note that AT&T's StarLAN is an orphaned technology, like SynOptics
  LattisNet, and can't be used in a standard 10Base-T environment.


  3.8.1.  AT&T T7231 (LanPACER+)


  Status -- Not    Supported

  These    StarLAN    cards use an interface similar to the i82586 chip. At
  one point, Matthijs Melchior ([e-mail]) was playing
  with the 3c507 driver, and almost had    something useable working.
  Haven't heard    much since that.


  3.9.    AT-Lan-Tec / RealTek



  3.9.1.  AT-Lan-Tec / RealTek Pocket adaptor


  Status -- Supported

  This is a generic, low-cost OEM pocket adaptor being sold by AT-Lan-
  Tec, and (likely) a number of    other suppliers. A driver for it is
  included in the standard kernel.  Note that there is substantial
  information contained    in the driver source file `atp.c'.  BTW, the
  adaptor (AEP-100L) has both 10baseT and BNC connections!  You    can
  reach    AT-Lan-Tec at 1-301-948-7070. Ask for the model    that works with
  Linux, or ask    for tech support.

  In the Netherlands a compatible adaptor is sold under    the name SHI-TEC
  PE-NET/CT, and sells for about $125. The vendor was Megasellers.  They
  state    that they do not sell to private persons, but this doesn't
  appear to be strictly    adhered    to.  They are: Megasellers, Vianen, The
  Netherlands. They always advertise in    Dutch computer magazines.  Note
  that the newer model EPP-NET/CT appears to be    significantly different
  than the PE-NET/CT, and will not work    with the present driver.
  Hopefully someone will come up with the programming information and
  this will be fixed up.

  In Germany, a    similar    adaptor    comes as a no-brand-name product. Prolan
  890b,    no brand on the    casing,    only a roman II. Resellers can get a
  price    of about $130, including a small wall transformer for the power.
  The adaptor is `normal size' for the product class, about 57mm wide,
  22mm high tapering to    15mm high at the DB25 connector, and 105mm long
  (120mm including the BNC socket). It's switchable between the    RJ45 and
  BNC jacks with a small slide switch positioned between the two: a very
  intuitive design.

  Donald performed some    power draw measurements, and determined    that the
  average current draw was only    about 100mA @ 5V.  This    power draw is
  low enough that you could buy    or build a cable to take the 5V    directly
  from the keyboard/mouse port available on many laptops. (Bonus points
  here for using a standardized    power connector    instead    of a proprietary
  one.)

  Note that the    device name that you pass to ifconfig is not eth0 but
  atp0 for this    device.



  3.10.     Boca Research


  Yes, they make more than just    multi-port serial cards.  :-)


  3.10.1.  Boca    BEN (PCI, VLB)


  Status -- Supported

  These    cards are based    on AMD's PCnet chips, used in the AT1500 and the
  like.    You can    pick up    a combo    (10BaseT and 10Base2) PCI card for under
  $70 at the moment.

  Supposedly Boca PCI cards can    have trouble with Pentium systems that
  are operating    faster than 66MHz. You may want    to check with Boca on
  this one. Note that this is not a driver problem, as it hits
  DOS/Win/NT users as well. Any    additional info    on this    as it develops
  would    be appreciated.

  More information can be found    in ``AMD LANCE''.

  More technical information on    AMD LANCE based    Ethernet cards can be
  found    in ``Notes on AMD...''.


  3.11.     Cabletron


  Donald writes: `Yes, another one of these companies that won't release
  its programming information. They waited for months before actually
  confirming that all their information    was proprietary, deliberately
  wasting my time. Avoid their cards like the plague if    you can.  Also
  note that some people    have phoned Cabletron, and have    been told things
  like `a D. Becker is working on a driver for linux' -- making    it sound
  like I work for them.    This is    NOT the    case.'

  If you feel like asking them why they    don't want to release their low
  level    programming info so that people    can use    their cards, write to
  [e-mail].  Tell them    that you are using Linux, and are
  disappointed that they don't support open systems. And no, the usual
  driver development kit they supply is    useless. It is just a DOS object
  file that you    are supposed to    link against. Which you    aren't allowed
  to even reverse engineer.



  3.11.1.  E10**, E10**-x, E20**, E20**-x


  Status -- Semi-Supported

  These    are NEx000 almost-clones that are reported to work with    the
  standard NEx000 drivers, thanks to a ctron-specific check during the
  probe. If there are any problems, they are unlikely to be fixed, as
  the programming information is unavailable.


  3.11.2.  E2100


  Status -- Semi-Supported

  Again, there is not much one can do when the programming information
  is proprietary.  The E2100 is    a poor design. Whenever    it maps    its
  shared memory    in during a packet transfer, it    maps it    into the whole
  128K region! That means you can't safely use another interrupt-driven
  shared memory    device in that region, including another E2100.     It will
  work most of the time, but every once    in a while it will bite    you.
  (Yes,    this problem can be avoided by turning off interrupts while
  transferring packets,    but that will almost certainly lose clock
  ticks.) Also,    if you mis-program the board, or halt the machine at
  just the wrong moment, even the reset    button won't bring it back. You
  will have to turn it off and leave it    off for    about 30 seconds.

  Media    selection is automatic,    but you    can override this with the low
  bits of the dev->mem_end parameter.  See ``PARAM_2''

  Also,    don't confuse the E2100    for a NE2100 clone.  The E2100 is a
  shared memory    NatSemi    DP8390 design, roughly similar to a brain-
  damaged WD8013, whereas the NE2100 (and NE1500) use a    bus-mastering
  AMD LANCE design.

  There    is an E2100 driver included in the standard kernel.  However,
  seeing as programming    info isn't available, don't expect bug-fixes.
  Don't    use one    unless you are already stuck with the card.



  3.12.     D-Link


  Some people have had difficulty in finding vendors that carry    D-link
  stuff. This should help.


          (714)    455-1688  in the US
          (081)    203-9900  in the UK
          6196-643011      in Germany
          (416)    828-0260  in Canada
          [phone]      in Taiwan




  3.12.1.  DE-100, DE-200, DE-220-T


  Status -- Supported

  The manual says that it is 100 % compatible with the NE2000. This is
  not true. You    should call them and tell them you are using their card
  with Linux, and they should correct their documentation. Some
  pre-0.99pl12 driver versions may have    trouble    recognizing the    DE2**
  series as 16 bit cards, and these cards are the most widely reported
  as having the    spurious transfer address mismatch errors. Note    that
  there    are cards from Digital (DEC) that are also named DE100 and
  DE200, but the similarity stops there.


  3.12.2.  DE-530


  Status -- Semi-Supported

  This appears to be a generic DEC 21040 PCI chip implementation, and
  will most likely work    with the generic 21040 driver.    However, nobody
  has verified this yet, and until that    has happened, it will remain
  listed as Semi-Supported.

  See ``DEC 21040'' for    more information on these cards, and the present
  driver situation.


  3.12.3.  DE-600


  Status -- Supported

  Laptop users and other folk who might    want a quick way to put    their
  computer onto    the ethernet may want to use this. The driver is
  included with    the default kernel source tree.     Bjorn Ekwall
  [e-mail]    wrote the driver.  Expect about    80kb/s transfer    speed
  from this via    the parallel port. You should read the README.DLINK file
  in the kernel    source tree.

  Note that the    device name that you pass to ifconfig is now eth0 and
  not the previously used dl0.

  If your parallel port    is not at the standard 0x378 then you will have
  to recompile.    Bjorn writes: ``Since the DE-620 driver    tries to sqeeze
  the last microsecond from the    loops, I made the irq and port address
  constants instead of variables. This makes for a usable speed, but it
  also means that you can't change these assignements from e.g.    lilo;
  you _have_ to    recompile...'' Also note that some laptops implement the
  on-board parallel port at 0x3bc which    is where the parallel ports on
  monochrome cards were/are.

  Supposedly, a    no-name    ethernet pocket    adaptor    marketed under the name
  `PE-1200' is DE-600 compatible.  It is available in Europe from:


      SEMCON Handels Ges.m.b.h
      Favoritenstrasse 20
      A-1040 WIEN
      Telephone: [phone]
      Fax       : [phone]




  3.12.4.  DE-620


  Status -- Supported

  Same as the DE-600, only with    two output formats.  Bjorn has written a
  driver for this model, for kernel versions 1.1 and above. See    the
  above    information on the DE-600.
  3.12.5.  DE-650


  Status -- Semi-Supported

  Some people have been    using this PCMCIA card for some    time now with
  their    notebooks. It is a basic 8390 design, much like    a NE2000. The
  LinkSys PCMCIA card and the IC-Card Ethernet (available from Midwest
  Micro) are supposedly    DE-650 clones as well.    Note that at present,
  this driver is not part of the standard kernel, and so you will have
  to do    some patching.

  See ``PCMCIA Support'' in this document, and if you can, have    a look
  at:

  Don's    PCMCIA Stuff (http://cesdis.gsfc.nasa.gov/linux/pcmcia.html)


  3.13.     DFI



  3.13.1.  DFINET-300 and DFINET-400


  Status -- Supported

  These    cards are now detected (as of 0.99pl15)    thanks to Eberhard
  Moenkeberg [e-mail] who noted that they use `DFI' in the first
  3 bytes of the prom, instead of using    0x57 in    bytes 14 and 15, which
  is what all the NE1000 and NE2000 cards use. (The 300    is an 8    bit
  pseudo NE1000    clone, and the 400 is a    pseudo NE2000 clone.)



  3.14.     Digital / DEC



  3.14.1.  DEPCA, DE100, DE200/1/2, DE210, DE422


  Status -- Supported

  As of    linux v1.0, there is a driver included as standard for these
  cards. It was    written    by David C. Davies.  There is documentation
  included in the source file `depca.c', which includes    info on    how to
  use more than    one of these cards in a    machine. Note that the DE422 is
  an EISA card.    These cards are    all based on the AMD LANCE chip.  See
  ``AMD    LANCE''    for more info.    A maximum of two of the    ISA cards can be
  used,    because    they can only be set for 0x300 and 0x200 base I/O
  address.  If you are intending to do this, please read the notes in
  the driver source file depca.c in the    standard kernel    source tree.


  3.14.2.  Digital EtherWorks 3    (DE203,    DE204, DE205)


  Status -- Supported

  Included into    kernels    v1.1.62    and above is this driver, also by David
  C. Davies of DEC. These cards    use a proprietary chip from DEC, as
  opposed to the LANCE chip used in the    earlier    cards like the DE200.
  These    cards support both shared memory or programmed I/O, although you
  take about a 50%performance hit if you use PIO mode. The shared memory
  size can be set to 2kB, 32kB or 64kB,    but only 2 and 32 have been
  tested with this driver. David says that the performance is virtually
  identical between the    2kB and    32kB mode. There is more information
  (including using the driver as a loadable module) at the top of the
  driver file ewrk3.c and also in README.ewrk3.     Both of these files
  come with the    standard kernel    distribution.

  Other    interesting notes are that it appears that David is/was    working
  on this driver for the unreleased version of Linux for the DEC Alpha
  AXP. And the standard    driver has a number of interesting ioctl() calls
  that can be used to get or clear packet statistics, read/write the
  EEPROM, change the hardware address, and the like. Hackers can see the
  source code for more info on that one.

  David    has also written a configuration utility for this card (along
  the lines of the DOS program NICSETUP.EXE) along with    other tools.
  These    can be found on    sunsite.unc.edu    in the directory
  /pub/Linux/system/Network/management -- look for the file ewrk3tools-
  X.XX.tar.gz.


  3.14.3.  DE425 (EISA), DE434,    DE435


  Status -- Supported

  These    cards are based    on the 21040 chip mentioned below.  Included
  into kernels v1.1.86 and above is this driver, also by David C. Davies
  of DEC. It sure is nice to have support from someone on the inside
  ;-) Have a read of the 21040 section for extra info.

  Note that as of 1.1.91, David    has added a compile time option    that may
  allow    non-DEC    cards (such as the ZYNX    cards) to work with this driver.
  Have a look at README.de4x5 for details.


  3.14.4.  DEC 21040, 21140, Tulip


  Status -- Supported

  The DEC 21040    is a bus-mastering single chip ethernet    solution from
  Digital, similar to AMD's PCnet chip.    The 21040 is specifically
  designed for the PCI bus architecture.  SMC's    new EtherPower PCI card
  uses this chip.  The new 21140 recently announced is for supporting
  100Base-? and    is supposed to be able to work with drivers for    the
  21040    chip.

  You have a choice of two drivers for cards based on this chip. There
  is the DE425 driver discussed    above, and the generic 21040 driver that
  Donald has written.

  To use David's de4x5 driver with non-DEC cards, have a look at
  README.de4x5 for details.

  Donald is doing his generic 21040 driver development on a SMC
  EtherPower PCI card at the moment, and this driver is    included in the
  standard kernel source as of 1.1.84.    Note that this driver is still
  considered an    alpha driver (see ``Alpha Drivers'') at    the moment, and
  should be treated as such. To    use it,    you will have to edit
  arch/i386/config.in and uncomment the    line for CONFIG_DEC_ELCP
  support.





  3.15.     Farallon

  Farallon sells EtherWave adaptors and    transceivers. This device allows
  multiple 10baseT devices to be daisy-chained.


  3.15.1.  Farallon Etherwave


  Status -- Supported

  This is reported to be a 3c509 clone that includes the EtherWave
  transceiver. People have used    these successfully with    Linux and the
  present 3c509    driver.    They are too expensive for general use,    but are
  a great option for special cases.  Hublet prices start at $125, and
  Etherwave adds $75-$100 to the price of the board -- worth it    if you
  have pulled one wire too few,    but not    if you are two network drops
  short.


  3.16.     Hewlett Packard


  The 272** cards use programmed I/O, similar to the NE*000 boards, but
  the data transfer port can be    `turned    off' when you aren't accessing
  it, avoiding problems    with autoprobing drivers.

  Thanks to Glenn Talbott for helping clean up the confusion in    this
  section regarding the    version    numbers    of the HP hardware.


  3.16.1.  27245A


  Status -- Supported

  8 Bit    8390 based 10BaseT, not    recommended for    all the    8 bit reasons.
  It was re-designed a couple years ago    to be highly integrated    which
  caused some changes in initialization    timing which only affected
  testing programs, not    LAN drivers. (The new card is not `ready' as
  soon after switching into and    out of loopback    mode.)


  3.16.2.  HP PC Lan+ (27247A, 27247B, 27252A)


  Status -- Supported

  The HP PC Lan+ is different to the standard HP PC Lan    card. This
  driver was added to the list of drivers in the standard kernel at
  about    v1.1.3X. Note that even    though the driver is included, the entry
  in `config.in' seems to have been omitted. If    you want to use    it, and
  it doesn't come up in    `config.in' then add the following line    to
  `config.in' under the     `HP PCLAN support' line:


      bool 'HP PCLAN Plus support' CONFIG_HPLAN_PLUS n



  Then run make    config;make dep;make zlilo or whatever.

  The 47B is a 16 Bit 8390 based 10BaseT w/AUI,    and the    52A is a 16 Bit
  8390 based ThinLAN w/AUI.  These cards are high performers (3c509
  speed) without the interrupt latency problems    (32K onboard RAM for TX
  or RX    packet buffering). They    both offer LAN connector autosense, data
  I/O in I/O space (simpler) or    memory mapped (faster),    and soft
  configuration.

  The 47A is the older model that existed before the `B'.  Two versions
  27247-60001 or 27247-60002 have part numbers marked on the card.
  Functionally the same    to the LAN driver, except bits in ROM to
  identify boards differ. -60002 has a jumper to allow operation in non-
  standard ISA busses (chipsets    that expect IOCHRDY early.)



  3.16.3.  HP-J2405A


  Status -- Supported

  These    are lower priced, and slightly faster than the 27247B/27252A,
  but are missing some features, such as AUI, ThinLAN connectivity, and
  boot PROM socket.  This is a fairly generic LANCE design, but    a minor
  design decision makes    it incompatible    with a generic `NE2100'    driver.
  Special support for it (including reading the    DMA channel from the
  board) is included thanks to information provided by HP's Glenn
  Talbott.

  More technical information on    LANCE based cards can be found in
  ``Notes on AMD...''


  3.16.4.  HP-Vectra On    Board Ethernet


  Status -- Supported

  The HP-Vectra    has an AMD PCnet chip on the motherboard.  Earlier
  kernel versions would    detect it as the HP-J2405A but that would fail,
  as the Vectra    doesn't    report the IRQ and DMA channel like the    J2405A.
  Get a    kernel newer than v1.1.53 to avoid this    problem.

  DMA selection    and chip numbering information can be found in ``AMD
  LANCE''.

  More technical information on    LANCE based cards can be found in
  ``Notes on AMD...''


  3.17.     IBM / International Business Machines



  3.17.1.  IBM Thinkpad    300


  Status -- Supported

  This is compatible with the Intel based Zenith Z-note.  See ``Z-note''
  for more info.

  Supposedly this site has a comprehensive database of useful stuff for
  newer    versions of the    Thinkpad. I haven't checked it out myself yet.

  Thinkpad-info    (http://peipa.essex.ac.uk/html/linux-thinkpad.html)

  For those without a WWW browser handy, try
  peipa.essex.ac.uk:/pub/tp750/


  3.17.2.  IBM Credit Card Adaptor for Ethernet


  Status -- Semi-Supported

  People have been using this PCMCIA card with Linux as    well.  Similar
  points apply,    those being that you need a supported PCMCIA chipset on
  your notebook, and that you will have    to patch the PCMCIA support into
  the standard kernel.

  See ``PCMCIA Support'' in this document, and if you can, have    a look
  at:

  Don's    PCMCIA Stuff (http://cesdis.gsfc.nasa.gov/linux/pcmcia.html)



  3.18.     Intel Ethernet    Cards



  3.18.1.  Ether Express


  Status -- Semi-Supported

  This card uses the intel i82586. (Surprise, huh?)  The driver    is in
  the standard release of the kernel, as an alpha driver. See ``Alpha
  Drivers'' for    important information on using alpha-test ethernet
  drivers with Linux.

  The reason is    that the driver    works well with    slow machines, but the
  i82586 occasionally hangs from the packet buffer contention that a
  fast machine can cause.  One reported    hack/fix is to change all of the
  outw() calls to outw_p(). Also, the driver is    missing    promiscuous and
  multicast modes. (See    ``Multicast and...'')

  There    is also    the standard way of using the chip (read slower) that is
  described in the chip    manual,    and used in other i82586 drivers, but
  this would require a re-write    of the entire driver.

  There    is some    technical information available    on the i82586 in
  ``Programming    the Intel Chips'' and also in the source code for the
  driver `eexpress.c'. Don't be    afraid to read it. ;-)


  3.18.2.  Ether Express PRO


  Status -- Not-Supported

  This card uses the Intel 82595. If it    is as ugly to use as the i82586,
  then don't count on anybody writing a    driver.


  3.19.     LinkSys



  3.19.1.  LinkSys PCMCIA Adaptor


  Status -- Semi-Supported

  This is supposed to be a re-badged DE-650. See the information on the
  DE-650 in ``DE-650''.
  3.20.     Microdyne



  3.20.1.  Microdyne Exos 205T


  Status -- Not-Supported

  Another i82586 based card. At    one point, [e-mail] had
  written a driver that    ``almost worked'' that was based on the    3c507
  code.    More details as    they are received...


  3.21.     Mylex



  3.21.1.  Mylex LNP101, LNP104


  Status -- Semi-Supported

  These    are PCI    cards that are based on    DEC's 21040 chip. The LNP104
  uses the 21050 chip to deliver four independent 10BaseT ports. The
  standard LNP101 is selectable    between    10BaseT, 10Base2 and 10Base5
  output.  The LNP101 card should work with the    generic    21040 driver,
  but nobody has verified this yet. As for the LNP 104,    well...

  See the section on the 21040 chip (``DEC 21040'') for    more
  information.

  Mylex    can be reached at the following    numbers, in case anyone    wants to
  ask them anything.


      MYLEX    CORPORATION, Fremont
      Sales:  800-77-MYLEX,    [phone]
      FAX:      (510)    745-8016.




  3.22.     Novell    Ethernet, NExxxx and associated    clones.


  The prefix `NE' came from Novell Ethernet. Novell followed the
  cheapest NatSemi databook design and sold the    manufacturing rights
  (spun    off?) Eagle, just to get reasonably-priced ethercards into the
  market. (The now ubiquitous NE2000 card.)


  3.22.1.  NE1000, NE2000


  Status -- Supported

  The now-generic name for a bare-bones    design around the NatSemi 8390.
  They use programmed I/O rather than shared memory, leading to    easier
  installation but slightly lower performance and a few    problems. Again,
  the savings of using an 8 bit    NE1000 over the    NE2000 are only
  warranted if you expect light    use. Some recently introduced NE2000
  clones use the National Semiconductor    `AT/LANTic' 83905 chip,    which
  offers a shared memory mode similar to the 8013 and EEPROM or    software
  configuration. Some problems can arise with poor clones. See
  ``Problems with...'',    and ``Poor NE2000 Clones'' In general it is not
  a good idea to put a NE2000 clone at I/O address 0x300 because nearly
  every    device driver probes there at boot. Some poor NE2000 clones
  don't    take kindy to being prodded in the wrong areas,    and will respond
  by locking your machine.

  Donald has written a NE2000 diagnostic program, but it is still
  presently in alpha test. (ne2k) See ``Diagnostic Programs'' for more
  information.


  3.22.2.  NE1500, NE2100


  Status -- Supported

  These    cards use the original 7990 LANCE chip from AMD    and are
  supported using the Linux lance driver.

  Some earlier versions    of the lance driver had    problems with getting
  the IRQ line via autoIRQ from    the original Novell/Eagle 7990 cards.
  Hopefully this is now    fixed.    If not,    then specify the IRQ via LILO,
  and let us know that it still    has problems.

  DMA selection    and chip numbering information can be found in ``AMD
  LANCE''.

  More technical information on    LANCE based cards can be found in
  ``Notes on AMD...''


  3.22.3.  NE3200


  Status -- Not    Supported

  This card uses a lowly 8MHz 80186, and hence you are better off using
  a cheap NE2000 clone.    Even if    a driver was available,    the NE2000 card
  would    most likely be faster.


  3.23.     Pure Data



  3.23.1.  PDUC8028, PDI8023


  Status -- Supported

  The PureData PDUC8028    and PDI8023 series of cards are    reported to
  work,    thanks to special probe    code contributed by Mike Jagdis
  [e-mail]. The support is integrated with the    WD
  driver.


  3.24.     Racal-Interlan



  3.24.1.  NI52**


  Status -- Semi-Supported

  Michael Hipp has written a driver for    this card. It is included in the
  standard kernel as an    `alpha'    driver.    Michael    would like to hear
  feedback from    users that have    this card. See ``Alpha Drivers'' for
  important information    on using alpha-test ethernet drivers with Linux.

  Michael says that ``the internal sysbus seems    to be slow. So we often
  lose packets because of overruns while receiving from    a fast remote
  host.''

  This card also uses one of the Intel chips. See ``Programming    the
  Intel    Chips''    for more technical information.



  3.24.2.  NI65**


  Status -- Semi-Supported

  There    is also    a driver for the LANCE based NI6510, and it is also
  written by Michael Hipp. Again, it is    also an    `alpha'    driver.    For some
  reason, this card is not compatible with the generic LANCE driver. See
  ``Alpha Drivers'' for    important information on using alpha-test
  ethernet drivers with    Linux.


  3.25.     Sager



  3.25.1.  Sager NP943


  Status -- Semi-Supported

  This is just a 3c501 clone, with a different S.A. PROM prefix. I
  assume it is equally as brain    dead as    the original 3c501 as well.
  Kernels 1.1.53 and up    check for the NP943 i.d. and then just treat it
  as a 3c501 after that. See ``3Com 3c501'' for    all the    reasons    as to
  why you really don't want to use one of these    cards.


  3.26.     Schneider & Koch



  3.26.1.  SK G16


  Status -- Supported

  This driver was included into    the v1.1 kernels, and it was written by
  PJD Weichmann    and SWS    Bern. It appears that the SK G16 is similar to
  the NI6510, in that it is based on the first edition LANCE chip (the
  7990). Once again, I have no idea as to why this card    won't work with
  the generic LANCE driver.


  3.27.     Western Digital / SMC (Standard Microsystems Corp.)


  The ethernet part of Western Digital has been    bought by SMC.    One
  common mistake people    make is    that the relatively new    SMC Elite Ultra
  is the same as the older SMC Elite16 models -- this is not the case.

  Here is how to contact SMC (not that you should need to.)


  SMC /    Standard Microsystems Corp., 80    Arkay Drive, Hauppage,
  New York, 11788, USA.


  Technical Support via    phone:

      800-992-4762 (USA)
      800-433-5345 (Canada)
      516-435-6250 (Other Countries)



  Literature requests:

      800-SMC-4-YOU    (USA)
      800-833-4-SMC    (Canada)
      516-435-6255    (Other Countries)



  Technical Support via    E-mail:

      [e-mail]



  FTP Site:

      ftp.smc.com




  3.27.1.  WD8003, SMC Elite

  Status -- Supported

  These    are the    8-bit versions of the card. The    8 bit 8003 is slightly
  less expensive, but only worth the savings for light use. Note that
  some of the non-EEPROM cards (clones with jumpers, or    old old    old
  wd8003 cards)    have no    way of reporting the IRQ line used. In this
  case,    auto-irq is used, and if that fails, the driver    silently assings
  IRQ 5.  Information regarding    what the jumpers on old    non-EEPROM
  wd8003 cards do can be found in conjunction with the SMC setup/driver
  disks    stored on dorm.rutgers.edu in the directory
  /pub/novell/nic_drvs/. Note that some    of the newer SMC `SuperDisk'
  programs will    fail to    detect the old EEPROM-less cards. The file
  SMCDSK46.EXE seems to    be a good all-round choice. Also the jumper
  settings for old cards are in    an ascii text file in the aforementioned
  archive. The latest (greatest?) version can be obtained from
  ftp.smc.com.

  As these are basically the same as their 16 bit counterparts (WD8013 /
  SMC Elite16),    you should see the next    section    for more information.



  3.27.2.  WD8013, SMC Elite16


  Status -- Supported

  Over the years the design has    added more registers and an EEPROM.
  Clones usually go by the `8013' name,    and usually use    a non-EEPROM
  (jumpered) design. This part of WD has been sold to SMC, so you'll
  usually see something    like SMC/WD8013    or SMC Elite16 Plus (WD8013).
  Late model SMC cards will have two main PLCC chips on    board; the SMC
  83c690 and the SMC 83c694.  The shared memory    design makes the cards
  10-20    % faster, especially with larger packets. More importantly, from
  the driver's point of    view, it avoids    a few bugs in the programmed-I/O
  mode of the 8390, allows safe    multi-threaded access to the packet
  buffer, and it doesn't have a    programmed-I/O data register that hangs
  your machine during warm-boot    probes.

  Non-EEPROM cards that    can't just read    the selected IRQ will attempt
  auto-irq, and    if that    fails, they will silently assign IRQ 10. (8 bit
  versions will    assign IRQ 5)

  Also see ``8013 clones'' and ``8013 problems''.


  3.27.3.  SMC Elite Ultra


  Status -- Supported

  This ethercard is based on a new chip    from SMC, with a few new
  features. While it has a mode    that is    similar    to the older SMC
  ethercards, it's not compatible with the old WD80*3 drivers. However,
  in this mode it shares most of its code with the other 8390 drivers,
  while    operating somewhat faster than a WD8013    clone.

  Since    part of    the Ultra looks    like an    8013, the Ultra    probe is
  supposed to find an Ultra before the wd8013 probe has    a chance to
  mistakenly identify it.

  Std. as of 0.99pl14, and made    possible by documentation and ethercard
  loan from Duke Kamstra. If you plan on using an Ultra    with Linux send
  him a    note of    thanks to let him know that there are Linux users out
  there!

  Donald mentioed that it is possible to write a separate driver for the
  Ultra's `Altego' mode    which allows chaining transmits    at the cost of
  inefficient use of receive buffers, but that will probably not happen
  right    away.  Performance re-writes of    working    drivers    are low    priority
  unless there is some particular incentive or need.

  Bus-Master SCSI host adaptor users take note:    In the manual that ships
  with Interactive UNIX, it mentions that a bug    in the SMC Ultra will
  cause    data corruption    with SCSI disks    being run from an aha-154X host
  adaptor.  This will probably bite aha-154X compatible    cards, such as
  the BusLogic boards, and the AMI-FastDisk SCSI host adaptors as well.

  Supposedly SMC has acknowledged the problem occurs with Interactive,
  and older Windows NT drivers.    It is supposed to be a hardware    conflict
  that can be worked around in the driver design. More on this as it
  develops.

  Some Linux users with    an Ultra + aha-154X compatible cards have
  experienced data corruption, while others have not.  Donald tried this
  combination himself, and wasn't able to reproduce the    problem. You
  have been warned.


  3.27.4.  SMC 8416 (EtherEZ)


  Status -- Supported

  This card uses SMC's 83c795 chip and supports    the Plug 'n Play
  specification. It also has an    SMC Ultra compatible mode, which allows
  it to    be used    with the Linux Ultra driver.  In this compatibility
  mode,    it uses    shared memory instead of programmed i/o. Be sure to set
  your card for    this compatibility mode.

  Note that the    EtherEZ    specific checks    were added to the SMC Ultra
  driver in 1.1.84, and    hence earlier kernel versions will not handle
  these    cards correctly.



  3.27.5.  SMC 8432 PCI    (EtherPower)


  Status -- Supported

  These    cards appear to    be a basic DEC 21040 implementation, i.e. one
  big chip and a couple    of transceivers. Donald    has used one of    these
  cards    for his    development of the generic 21040 driver. Thanks    to Duke
  Kamstra, once    again, for supplying a card to do development on.  See
  ``DEC    21040''    for more details on using one of these cards, and the
  current status of the    driver.


  3.27.6.  SMC 3008


  Status -- Not    Supported

  These    8 bit cards are    based on the Fujitsu MB86950, which is an
  ancient version of the MB86965 used in the Linux at1700 driver. Russ
  says that you    could probably hack up a driver    by looking at the
  at1700.c code    and his    DOS packet driver for the Tiara    card (tiara.asm)


  3.27.7.  SMC 3016


  Status -- Not    Supported

  These    are 16bit i/o mapped 8390 cards, much similar to a generic
  NE2000 card. If you can get the specifications from SMC, then    porting
  the NE2000 driver would probably be quite easy.


  3.27.8.  SMC 9000


  Status -- Not    Supported

  These    cards are VLB cards based on the 91c92 chip. They are fairly
  expensive, and hence the demand for a    driver is pretty low at    the
  moment.


  3.28.     Xircom


  Another group    that won't release documentation. No cards supported.
  Don't    look for any support in    the future unless they release their
  programming information. And this is highly unlikely,    as they    forbid
  you from even    reverse- engineering their drivers. If you are already
  stuck    with one, see if you can trade it off on some DOS (l)user.

  And if you just want to verify that this is the case,    you can    reach
  Xircom at 1-800-874-7875, 1-800-438-4526 or [phone].    They
  used to advertise that their products    "work with all network operating
  systems", but    have since stopped. Wonder why...
  3.28.1.  PE1,    PE2, PE3-10B*


  Status -- Not    Supported

  Not to get your hopes    up, but    if you have one    of these parallel port
  adaptors, you    may be able to use it in the DOS emulator with the
  Xircom-supplied DOS drivers. You will    have to    allow DOSEMU access to
  your parallel    port, and will probably    have to    play with SIG (DOSEMU's
  Silly    Interrupt Generator). I    have no    idea if    this will work,    but if
  you have any success with it,    let me know, and I will    include    it here.


  3.29.     Zenith



  3.29.1.  Z-Note


  Status -- Supported

  The built-in Z-Note network adaptor is based on the Intel i82593 using
  two DMA channels. There is an    (alpha?) driver    available in the present
  kernel version. As with all notebook and pocket adaptors, it is under
  the `Pocket and portable adaptors' section when running make config.
  See ``Programming the    Intel chips'' for more technical information.
  Also note that the IBM ThinkPad 300 is compatible with the Z-Note.


  3.30.     Zynx



  3.30.1.  Zynx    (DEC 21040 based)


  Status -- Supported

  You have a choice of two drivers for cards based on this chip. There
  is the DE425 driver written by David,    and the    generic    21040 driver
  that Donald has written.

  Note that as of 1.1.91, David    has added a compile time option    that may
  allow    non-DEC    cards (such as the Zynx    cards) to work with this driver.
  Have a look at README.de4x5 for details.

  See ``DEC 21040'' for    more information on these cards, and the present
  driver situation.


  4.  Clones of    popular    Ethernet cards.


  Due to the popular design of some cards, different companies will make
  `clones' or replicas of the original card. However, one must be
  careful, as some of these clones are not 100 % compatible, and can be
  troublesome. Some common problems with `not-quite-clones' are    noted in
  ``the    FAQ section''.

  This section used to have a listing of a whole bunch of clones that
  were reported    to work, but seeing as nearly all clones will work, it
  makes    more sense to list the ones that don't work 100    % .



  4.1.    Poor NE2000 Clones


  Here is a list of some of the    NE-2000    clones that are    known to have
  various problems. Most of them aren't    fatal. In the case of the ones
  listed as `bad clones' -- this usually indicates that    the cards don't
  have the two NE2000 identifier bytes.    NEx000-clones have a Station
  Address PROM (SAPROM)    in the packet buffer memory space.  NE2000
  clones have 0x57,0x57    in bytes 0x0e,0x0f of the SAPROM, while    other
  supposed NE2000 clones must be detected by their SA prefix.

  Accton NE2000    -- might not get detected at boot, see ``ne2000
  problems''.

  Aritsoft LANtastic AE-2 -- OK, but has flawed    error-reporting
  registers.

  AT-LAN-TEC NE2000 -- clone uses Winbond chip that traps SCSI drivers

  ShineNet LCS-8634 -- clone uses Winbond chip that traps SCSI drivers

  Cabletron E10**, E20**, E10**-x, E20**-x -- bad clones, but the driver
  checks for them. See ``E10**''.

  D-Link Ethernet II --    bad clones, but    the driver checks for them. See
  ``DE-100 / DE-200''.

  DFI DFINET-300, DFINET-400 --    bad clones, but    the driver checks for
  them.    See ``DFI-300 /    DFI-400''


  4.2.    Poor WD8013 Clones


  I haven't heard of any bad clones of these cards, except perhaps for
  some chamelion-type cards that can be    set to look like a ne2000 card
  or a wd8013 card. There is really no need to purchase    one of these
  `double-identity' cards anyway.


  5.  Cables, Coax, Twisted Pair

  If you are starting a    network    from scratch, it's considerably    less
  expensive to use thin    ethernet, RG58 co-ax cable with    BNC connectors,
  than old-fashioned thick ethernet, RG-5 cable    with N connectors, or
  10baseT, twisted pair    telco-style cables with    RJ-45 eight wire `phone'
  connectors. See ``Type of cable...'' for an introductory look    at
  cables.

  Also note that the FAQ from comp.dcom.lans.ethernet has a lot    of
  useful information on    cables and such. Look in dorm.rutgers.edu for
  the file /pub/novell/info_and_docs/Ethernet.FAQ


  5.1.    Thin Ethernet (thinnet)


  Thin ethernet    is the `ether of choice'. The cable is inexpensive. If
  you are making your own cables solid-core RG58A is $0.27/m. and
  stranded RG58AU is $0.45/m. Twist-on BNC connectors are < $2 ea., and
  other    misc. pieces are similarly inexpensive.    It is essential    that you
  properly terminate each end of the cable with    50 ohm terminators, so
  budget $2 ea.    for a pair. It's also vital that your cable have no
  `stubs' -- the `T' connectors    must be    attached directly to the
  ethercards. The only drawback    is that    if you have a big loop of
  machines connected together, and some    bonehead breaks    the loop by
  taking one cable off the side    of his tee, the    whole network goes down
  because it sees an infinite impedance    (open circuit) instead of the
  required 50 ohm termination. Note that you can remove    the tee    piece
  from the card    itself without killing the whole subnet, as long as you
  don't    remove the cables from the tee itself. Of course this will
  disturb the machine that you pull the    actual tee off of. 8-) And if
  you are doing    a small    network    of two machines, you still need    the tees
  and the 50 ohm terminators --    you can't just cable them together!



  5.2.    Twisted    Pair


  Twisted pair networks    require    active hubs, which start around    $200,
  and the raw cable cost can actually be higher    than thinnet. They are
  usually sold using the claim that you    can use    your existing telephone
  wiring, but it's a rare installation where that turns    out to be the
  case.    The claim that you can upgrade to higher speeds    is also    suspect,
  as most proposed schemes use higher-grade (read $$) cable and    more
  sophisticated    termination ($$$) than you would likely    install    on
  speculation. New gizmos are floating around which allow you to daisy-
  chain    machines together, and the like. For example, Farallon sells
  EtherWave adaptors and transceivers. This device allows multiple
  10baseT devices to be    daisy-chained. They also sell a    3c509 clone that
  includes the EtherWave transceiver.  The drawback is that it's more
  expensive and    less reliable than a cheap ($100-$150) mini-hub    and
  another ethercard.  You probably should either go for    the hub    approach
  or switch over to 10base2 thinnet.

  On the other hand, hubs are rapidly dropping in price, all 100Mb/sec
  ethernet proposals use twisted pair, and most    new business
  installations    use twisted pair. (This    is probably to avoid the problem
  with idiots messing with the BNC's as    described above.)

  Also,    Russ Nelson adds that `New installations should    use Category 5
  wiring. Anything else    is a waste of your installer's time, as    100Base-
  whatever is going to require Cat 5.'

  If you are only connecting two machines, it is possible to avoid using
  a hub, by swapping the Rx and    Tx pairs (1-2 and 3-6).

  If you hold the RJ-45    connector facing you (as if you    were going to
  plug it into your mouth) with    the lock tab on    the top, then the pins
  are numbered 1 to 8 from left    to right. The pin usage    is as follows:


      Pin Number          Assignment
      ----------          ----------
      1              Output Data (+)
      2              Output Data (-)
      3              Input    Data (+)
      4              Reserved for Telephone use
      5              Reserved for Telephone use
      6              Input    Data (-)
      7              Reserved for Telephone use
      8              Reserved for Telephone use



  Some cards, like the wd8013 can sense    reversed polarity, and will
  adjust accordingly. Also note    that 3 and 6 must be a twisted pair. If
  you make 3-4 a twisted pair, and 5-6 the other twisted pair, your
  cable    may work for lengths less than a metre,    but will fail miserably
  for longer lengths.

  Note that before 10BaseT was ratified    as a standard, there existed
  other    network    formats    using RJ-45 connectors,    and the    same wiring
  scheme as above. Examples are    SynOptics's LattisNet, and AT&T's
  StarLAN.  In some cases, (as with early 3C503    cards) you could set
  jumpers to get the card to talk to hubs of different types, but in
  most cases cards designed for    these older types of networks will not
  work with standard 10BaseT networks/hubs. (Note that if the cards also
  have an AUI port, then there is no reason as to why you can't    use
  that,    combined with an AUI to    10BaseT    transceiver.)


  5.3.    Thick Ethernet

  Thick    ethernet is mostly obsolete, and is usually used only to remain
  compatible with an existing implementation. You can stretch the rules
  and connect short spans of thick and thin ethernet together with a
  passive $3 N-to-BNC connector, and that's often the best solution to
  expanding an existing    thicknet. A correct (but expensive) solution is
  to use a repeater in this case.

  6.  Software Configuration and Card Diagnostics


  In most cases, if the    configuration is done by software, and stored in
  an EEPROM, you will usually have to boot DOS,    and use    the supplied DOS
  program to set the cards IRQ,    I/O, mem_addr and whatnot. Besides,
  hopefully it is something you    will only be setting once. For those
  that don't have the DOS utility available, note that a fair number of
  NIC setup/driver disks (e.g. 3Com, SMC/WD and    Allied Telesis NIC's)
  are available    from dorm.rutgers.edu in the directory
  /pub/novell/nic_drvs/    However, there are some    cards for which    Linux
  versions of the config utils exist, and they are listed here.

  Also,    Donald has written a few small card diagnostic programs    that run
  under    Linux. Most of these are a result of debugging tools that he has
  created while    writing    the various drivers. Don't expect fancy    menu-
  driven interfaces. You will have to read the source code to use most
  of these. Even if your particular card doesn't have a    corresponding
  diagnostic, you can still get    lots of    information just by typing cat
  /proc/net/dev    -- assuming that your card was at least    detected at
  boot.

  In either case, you will have    to run most of these programs as root
  (to allow I/O    to the ports) and you probably want to shut down the
  ethercard before doing so by typing ifconfig eth0 down (Note:    replace
  eth0 with atp0 or whatever when appropriate.)


  6.1.    Configuration Programs for Ethernet Cards


  For people with wd80x3 cards,    there is the program wdsetup which can
  be found in wdsetup-0.6a.tar.gz on Linux ftp sites.  I am not    sure if
  it is    being actively maintained or not, as it    has not    been updated for
  quite    a while. If it works fine for you then great, if not, use the
  DOS version that you should have got with your card. If you don't have
  the DOS version, you will be glad to know that the SMC setup/driver
  disks    are available at the dorm.rutgers.edu site mentioned above.  Of
  course, you have to have an EEPROM card to use this utility.    Old, old
  wd8003 cards,    and some wd8013    clones use jumpers to set up the card
  instead.

  The Digital EtherWorks 3 card    can be configured in a similar fashion
  to the DOS program NICSETUP.EXE. David C. Davies wrote this and other
  tools    for the    EtherWorks 3 in    conjunction with the driver. Look on
  sunsite.unc.edu in the directory /pub/linux/system/Network/management
  for the file that is named ewrk3tools-X.XX.tar.gz.

  Some Nat Semi    DP83905    implementations    (such as the AT/LANTIC and the
  NE2000+) are software    configurable. (Note that this card can also
  emulate a wd8013!) You can get the file /pub/linux/setup/atlantic.c
  from Donald's    ftp server, cesdis.gsfc.nasa.gov to configure this card.
  Be careful when configuring NE2000+ cards, as    you can    give them bad
  setting values which will require you    to open    the case and switch a
  jumper to force it back to sane settings.

  The 3Com Etherlink III family    of cards (i.e. 3c5x9) can be configured
  by using another config utility from Donald.    You can    get the    file
  /pub/linux/setup/3c5x9setup.c    from Donald's ftp server,
  cesdis.gsfc.nasa.gov to configure these cards. (Note that the    DOS
  3c5x9B config    utility    may have more options pertaining to the    new
  ``B''    series of the Etherlink    III family.)




  6.2.    Diagnostic Programs for    Ethernet Cards


  Any of the diagnostic    programs that Donald has written can be    obtained
  from this URL.

  Ethercard Diagnostics
  (http://cesdis.gsfc.nasa.gov/pub/linux/diag/diagnostic.html)

  Allied Telesis AT1700    -- look    for the    file /pub/linux/diag/at1700.c on
  cesdis.gsfc.nasa.gov.

  Cabletron E21XX -- look for the file /pub/linux/diag/e21.c on
  cesdis.gsfc.nasa.gov.

  HP PCLAN+ -- look for    the file /pub/linux/diag/hp+.c on
  cesdis.gsfc.nasa.gov.

  Intel    EtherExpress --    look for the file /pub/linux/diag/eexpress.c on
  cesdis.gsfc.nasa.gov.

  NE2000 cards -- look for the file /pub/linux/diag/ne2k.c on
  cesdis.gsfc.nasa.gov.

  RealTek (ATP)    Pocket adaptor -- look for the file /pub/linux/diag/atp-
  diag.c on cesdis.gsfc.nasa.gov.

  All Other Cards -- try typing    cat /proc/net/dev and see what useful
  info the kernel has on the card in question.


  7.  Technical    Information


  For those who    want to    play with the present drivers, or try to make up
  their    own driver for a card that is presently    unsupported, this
  information should be    useful.    If you do not fall into    this category,
  then perhaps you will    want to    skip this section.


  7.1.    Probed Addresses


  While    trying to determine what ethernet card is there, the following
  addresses are    autoprobed, assuming the type and specs    of the card have
  not been set in the kernel. The file names below are in
  /usr/src/linux/drivers/net/


  ______________________________________________________________________
      3c501.c      0x280, 0x300
      3c503.c:      0x300, 0x310,    0x330, 0x350, 0x250, 0x280, 0x2a0, 0x2e0
      3c505.c:      0x300, 0x280,    0x310
      3c507.c:      0x300, 0x320,    0x340, 0x280
      3c509.c:      Special ID Port probe
      apricot.c      0x300
      at1700.c:      0x300, 0x280,    0x380, 0x320, 0x340, 0x260, 0x2a0, 0x240
      atp.c:      0x378, 0x278,    0x3bc
      depca.c      0x300, 0x200
      de600.c:      0x378
      de620.c:      0x378
      eexpress.c:      0x300, 0x270,    0x320, 0x340
      hp.c:          0x300, 0x320,    0x340, 0x280, 0x2C0, 0x200, 0x240
      hp-plus.c      0x200, 0x240,    0x280, 0x2C0, 0x300, 0x320, 0x340
      lance.c:      0x300, 0x320,    0x340, 0x360
      ne.c:          0x300, 0x280,    0x320, 0x340, 0x360
      ni52.c      0x300, 0x280,    0x360, 0x320, 0x340
      ni65.c      0x300, 0x320,    0x340, 0x360
      smc-ultra.c:      0x200, 0x220,    0x240, 0x280, 0x300, 0x340, 0x380
      wd.c:          0x300, 0x280,    0x380, 0x240
  ______________________________________________________________________



  There    are some NE2000    clone ethercards out there that    are waiting
  black    holes for autoprobe drivers. While many    NE2000 clones are safe
  until    they are enabled, some can't be    reset to a safe    mode.  These
  dangerous ethercards will hang any I/O access    to their `dataports'.
  The typical dangerous    locations are:

  ______________________________________________________________________
      Ethercard jumpered base     Dangerous    locations (base    + 0x10 - 0x1f)
          0x300    *              0x310-0x317
          0x320                  0x330-0x337
          0x340                  0x350-0x357
          0x360                  0x370-0x377
  ______________________________________________________________________



  * The    0x300 location is the traditional place    to put an ethercard, but
  it's also a popular place to put other devices (often    SCSI
  controllers).    The 0x320 location is often the    next one chosen, but
  that's bad for for the AHA1542 driver    probe. The 0x360 location is
  bad, because it conflicts with the parallel port at 0x378.  If you
  have two IDE controllers, or two floppy controlers, then 0x360 is also
  a bad    choice,    as a NE2000 card will clobber them as well.

  Note that kernels > 1.1.7X keep a log    of who uses which i/o ports, and
  will not let a driver    use i/o    ports registered by an earlier driver.
  This may result in probes silently failing.  You can view who    is using
  what i/o ports by typing cat /proc/ioports if    you have the proc
  filesystem enabled.

  To avoid these lurking ethercards, here are the things you can do:


  o  Probe for the device's BIOS in memory space. This is easy and
     always safe, but it only works for    cards that always have BIOSes,
     like primary SCSI controllers.


  o  Avoid probing any of the above locations until you    think you've
     located your device. The NE2000 clones have a reset range from
     <base>+0x18 to <base>+0x1f    that will read as 0xff,    so probe there
     first if possible.    It's also safe to probe    in the 8390 space at
     <base>+0x00 - <base>+0x0f,    but that area will return quasi-random
     values

  o  If    you must probe in the dangerous    range, for instance if your
     target device has only a few port locations, first    check that there
     isn't an NE2000 there. You    can see    how to do this by looking at the
     probe code    in /usr/src/linux/net/inet/ne.c

  o  Use the `reserve' boot time argument to protect volatile areas from
     being probed. See the information on using    boot time arguments with
     LILO in ``The reserve command''


  7.2.    Skeleton / prototype driver



  OK. So you have decided that you want    to write a driver for the Foobar
  Ethernet card, as you    have the programming information, and it hasn't
  been done yet. (...these are the two main requirements ;-) You can use
  the skeleton network driver that is provided with the    Linux kernel
  source tree. It can be found in the file
  /usr/src/linux/drivers/net/skeleton.c    as of 0.99pl15,    and later.

  It's also very useful    to look    at the Crynwr (nee Clarkson) driver for
  your target ethercard, if it's available. Russ Nelson
  [e-mail] has    been actively updating and writing these, and he
  has been very    helpful    with his code reviews of the current Linux
  drivers.


  7.3.    Driver interface to the    kernel


  Here are some    notes that may help when trying    to figure out what the
  code in the driver segments is doing,    or perhaps what    it is supposed
  to be    doing.


  ______________________________________________________________________
      int ethif_init(struct    device *dev)
      {
          ...
          dev->send_packet = &ei_send_packet;
          dev->open = &ei_open;
          dev->stop = &ei_close;
          dev->hard_start_xmit = &ei_start_xmit;
          ...
      }

      int ethif_init(struct    device *dev)
  ______________________________________________________________________



  This function    is put into the    device structure in Space.c. It    is
  called only at boot time, and    returns    `0' iff    the ethercard `dev'
  exists.




  ______________________________________________________________________
      static int ei_open(struct device *dev)
      static int ei_close(struct device *dev)
  ______________________________________________________________________



  This routine opens and initializes the board in response to an socket
  ioctl() usually called by `ifconfig'.    It is commonly stuffed into the
  `struct device' by ethif_init().

  The inverse routine is ei_close(), which should shut down the
  ethercard, free the IRQs and DMA channels if the hardware permits, and
  turn off anything that will save power (like the transceiver).


  ______________________________________________________________________
      static int ei_start_xmit(struct sk_buff *skb,    struct device *dev)
          dev->hard_start_xmit = &ei_start_xmit;
  ______________________________________________________________________



  This routine puts packets to be transmitted into the hardware. It is
  usually stuffed into the `struct device' by ethif_init().

  When the hardware can't accept additional packets it should set the
  dev->tbusy flag. When    additional room    is available, usually during a
  transmit-complete interrupt, dev->tbusy should be cleared and    the
  higher levels    informed with mark_bh(INET_BH).


  ______________________________________________________________________
          if (dev_rint(buffer, length, is_skb ? IN_SKBUFF :    0, dev))
             stats->rx_dropped++;
  ______________________________________________________________________



  A received packet is passed to the higher levels using dev_rint().  If
  the unadorned    packet data in a memory    buffer,    dev_rint will copy it
  into a `skbuff' for you. Otherwise a new skbuff should be kmalloc()ed,
  filled, and passed to    dev_rint() with    the IN_SKBUFF flag.


  ______________________________________________________________________
      int s=socket(AF_INET,SOCK_PACKET,htons(ETH_P_ALL));
  ______________________________________________________________________



  Gives    you a socket receving every protocol type. Do recvfrom() calls
  to it    and it will fill the sockaddr with device type in sa_family and
  the device name in the sa_data array.    I don't    know who originally
  invented SOCK_PACKET for Linux (its been in for ages)    but its    superb
  stuff.  You can use it to send stuff raw too (both only as root).



  7.4.    Interrupts and Linux


  There    are two    kinds of interrupt handlers in Linux: fast ones    and slow
  ones.    You decide what    kind you are installing    by the flags you pass to
  irqaction(). The fast    ones, such as the serial interrupt handler, run
  with _all_ interrupts    disabled. The normal interrupt handlers, such as
  the one for ethercard    drivers, runs with other interrupts enabled.

  There    is a two-level interrupt structure. The    `fast' part handles the
  device register, removes the packets,    and perhaps sets a flag.  After
  it is    done, and interrupts are re-enabled, the slow part is run if the
  flag is set.

  The flag between the two parts is set    by:


       mark_bh(INET_BH);


  Usually this flag is set within dev_rint() during a received-packet
  interrupt, and set directly by the device driver during a transmit-
  complete interrupt.

  You might wonder why all interrupt handlers cannot run in `normal
  mode'    with other interrupts enabled. Ross Biro uses this scenario to
  illustrate the problem:


  o  You get a serial interrupt, and start processing it.  The serial
     interrupt is now masked.

  o  You get a network interrupt, and you start    transferring a maximum-
     sized 1500    byte packet from the card.

  o  Another character comes in, but this time the interrupts are
     masked!

  The `fast' interrupt structure solves    this problem by    allowing
  bounded-time interrupt handlers to run without the risk of leaving
  their    interrupt lines    masked by another interrupt request.

  There    is an additional distinction between fast and slow interrupt
  handlers -- the arguments passed to the handler. A `slow' handler is
  defined as


  ______________________________________________________________________

          static void
          handle_interrupt(int reg_ptr)
          {
              int irq =    -(((struct pt_regs *)reg_ptr)->orig_eax+2);
              struct device *dev = irq2dev_map[irq];
          ...
  ______________________________________________________________________



  While    a fast handler gets the    interrupt number directly


  ______________________________________________________________________

          static void
          handle_fast_interrupt(int irq)
          {
          ...
  ______________________________________________________________________




  A final aspect of network performance    is latency. The    only board that
  really addresses this    is the 3c509, which allows a predictive
  interrupt to be posted. It provides an interrupt response timer so
  that the driver can fine-tune    how early an interrupt is generated.

  Alan Cox has some advice for anyone wanting to write drivers that are
  to be    used with 0.99pl14 kernels and newer. He says:

  `Any driver intended for 0.99pl14 should use the new alloc_skb() and
  kfree_skbmem() functions rather than using kmalloc() to obtain a
  sk_buff. The new 0.99pl14 skeleton does this correctly. For drivers
  wishing to remain compatible with both sets the define
  `HAVE_ALLOC_SKB' indicates these functions must be used.

  In essence replace


       skb=(struct sk_buff *)kmalloc(size)


  with


       skb=alloc_skb(size)


  and


       kfree_s(skb,size)


  with


       kfree_skbmem(skb,size)  /* Only sk_buff memory though */


  Any questions    should I guess be directed to me (Alan Cox) since I made
  the change.  This is a change    to allow tracking of sk_buff's and
  sanity checks    on buffers and stack behaviour.    If a driver produces the
  message'File:    ??? Line: ??? passed a non skb!' then it is probable the
  driver is not    using the new sk_buff allocators.'



  7.5.    Programmed I/O vs. Shared Memory vs. DMA


  Ethernet is 10Mbs. (Don't be pedantic, 3Mbs and 100Mbs don't count.)
  If you can already send and receive back-to-back packets, you    just
  can't    put more bits over the wire. Every modern ethercard can    receive
  back-to-back packets.    The Linux DP8390 drivers come pretty close to
  sending back-to-back packets (depending on the current interrupt
  latency) and the 3c509 and AT1500 hardware has no problem at all
  automatically    sending    back-to-back packets.

  The ISA bus can do 5.3MB/sec (42Mb/sec), which sounds    like more than
  enough. You can use that bandwidth in    several    ways:


  7.5.1.  Programmed I/O


  Pro: Doesn't use any constrained system resources, just a few    I/O
  registers, and has no    16M limit.
  Con: Usually the slowest transfer rate, the CPU is waiting the whole
  time,    and interleaved    packet access is usually difficult to
  impossible.


  7.5.2.  Shared memory


  Pro: Simple, faster than programmed I/O, and allows random access to
  packets.

  Con: Uses up memory space (a big one for DOS users, only a minor issue
  under    Linux),    and it still ties up the CPU.


  7.5.3.  Slave    (normal) Direct    Memory Access


  Pro: Frees up    the CPU    during the actual data transfer.

  Con: Checking    boundary conditions, allocating    contiguous buffers, and
  programming the DMA registers    makes it the slowest of    all techniques.
  It also uses up a scarce DMA channel,    and requires aligned low memory
  buffers.


  7.5.4.  Master Direct    Memory Access (bus-master)


  Pro: Frees up    the CPU    during the data    transfer, can string together
  buffers, can require little or no CPU    time lost on the ISA bus.

  Con: Requires    low-memory buffers and a DMA channel. Any bus-master
  will have problems with other    bus-masters that are bus-hogs, such as
  some primitive SCSI adaptors.    A few badly-designed motherboard
  chipsets have    problems with bus-masters. And a reason    for not    using
  any type of DMA device is using a Cyrix 486 processor    designed for
  plug-in replacement of a 386:    these processors must flush their cache
  with each DMA    cycle. (This includes the Cx486DLC, Ti486DLC, Cx486SLC,
  Ti486SLC, etc.)


  7.6.    Programming the    Intel chips (i82586 and    i82593)


  These    chips are used on a number of cards, namely the    3c507 ('86), the
  Intel    EtherExpress 16    ('86), Microdyne's exos205t ('86), the Z-Note
  ('93), and the Racal-Interlan    ni5210 ('86).

  Russ Nelson writes: `Most boards based on the    82586 can reuse    quite a
  bit of their code.  More, in fact, than the 8390-based adapters. There
  are only three differences between them:


  o  The code to get the Ethernet address,

  o  The code to trigger CA on the 82586, and

  o  The code to reset the 82586.

  The Intel EtherExpress 16 is an exception, as    it I/O maps the    82586.
  Yes, I/O maps    it. Fairly clunky, but it works.

  Garrett Wollman did an AT&T driver for BSD that uses the BSD
  copyright. The latest    version    I have (Sep '92) only uses a single
  transmit buffer. You can and should do better    than this if you've got
  the memory. The AT&T and 3c507 adapters do; the ni5210 doesn't.

  The people at    Intel gave me a    very big clue on how you queue up
  multiple transmit packets. You set up    a list of NOP->    XMIT-> NOP->
  XMIT-> NOP-> XMIT-> beginning) blocks, then you set the `next' pointer
  of all the NOP blocks    to themselves. Now you start the command unit on
  this chain. It continually processes the first NOP block. To transmit
  a packet, you    stuff it into the next transmit    block, then point the
  NOP to it. To    transmit the next packet, you stuff the    next transmit
  block    and point the previous NOP to it. In this way, you don't have to
  wait for the previous    transmit to finish, you    can queue up multiple
  packets without any ambiguity    as to whether it got accepted, and you
  can avoid the    command    unit start-up delay.'


  7.7.    Technical information from 3Com



      From:    Cameron    Spitzer    764-6339 <[e-mail]    > Subject: getting 3Com    Adapter    manuals
      Date:    Mon, 27    Sep 1993 21:17:07 +0200



  Since    this is    becoming a FAQ,    I'm going to tread the thin ice    of No
  Commercial Use and answer it here.

  3Com's Ethernet Adapters are documented for driver writers in    our
  `Technical References' (TRs).    These manuals describe the programmer
  interfaces to    the boards but they don't talk about the diagnostics,
  installation programs, etc that end users can    see.

  The Network Adapter Division marketing department has    the TRs    to give
  away.    To keep    this program efficient,    we centralized it in a thing
  called `CardFacts.' CardFacts    is an automated    phone system. You call
  it with a touch-tone phone and it faxes you stuff. To    get a TR, call
  CardFacts at 408-727-7021. Ask it for    Developer's Order Form,    document
  number 9070. Have your fax number ready when you call. Fill out the
  order    form and fax it    to 408-764-5004.  Manuals are shipped by Federal
  Express 2nd Day Service.

  If you don't have a fax and nobody you know has a fax, really    and
  truly, then send mail    to [e-mail] and tell    her
  about    your problem.  PLEASE use the fax thing    if you possibly    can.

  After    you get    a manual, if you still can't figure out    how to program
  the board, try our `CardBoard' BBS at    1-800-876-3266,    and if you can't
  do that, write [e-mail] and ask him for alternatives.
  If you have a    real stumper that nobody has figured out yet, the fellow
  who needs to know about it is    [e-mail].

  There    are people here    who think we are too free with the manuals, and
  they are looking for evidence    that the system    is too expensive, or
  takes    too much time and effort. That's why it's important to try to
  use CardFacts    before you start calling and mailing the people    I named
  here.

  There    are even people    who think we should be like Diamond and    Xircom,
  requiring tight `partnership'    with driver writers to prevent poorly
  performing drivers from getting written. So far, 3Com    customers have
  been really good about this, and there's no problem with the level of
  requests we've been getting. We need your continued cooperation and
  restraint to keep it that way.

  Cameron Spitzer, 408-764-6339    3Com NAD Santa Clara work:
  [e-mail]    home: [e-mail]
  7.8.    Notes on AMD PCnet / LANCE Based cards


  The AMD LANCE    (Local Area Network Controller for Ethernet) was the
  original offering, and has since been    replaced by the    `PCnet-ISA'
  chip,    otherwise known    as the 79C960.    A relatively new chip from AMD,
  the 79C960, is the heart of many new cards being released at present.
  Note that the    name `LANCE' has stuck,    and some people    will refer to
  the new chip by the old name.    Dave Roberts of    the Network Products
  Division of AMD was kind enough to contribute    the following
  information regarding    this chip:

  `As for the architecture itself, AMD developed it originally and
  reduced it to    a single chip -- the PCnet(tm)-ISA -- over a year ago.
  It's been selling like hotcakes ever since.

  Functionally,    it is equivalent to a NE1500. The register set is
  identical to the old LANCE with the 1500/2100    architecture additions.
  Older    1500/2100 drivers will work on the PCnet-ISA.  The NE1500 and
  NE2100 architecture is basically the same.  Initially    Novell called it
  the 2100, but    then tried to distinguish between coax and 10BASE-T
  cards. Anything that was 10BASE-T only was to    be numbered in the 1500
  range. That's    the only difference.

  Many companies offer PCnet-ISA based products, including HP, Racal-
  Datacom, Allied Telesis, Boca    Research, Kingston Technology, etc.  The
  cards    are basically the same except that some    manufacturers have added
  `jumperless' features    that allow the card to be configured in
  software. Most have not. AMD offers a    standard design    package    for a
  card that uses the PCnet-ISA and many    manufacturers use our design
  without change.  What    this means is that anybody who wants to    write
  drivers for most PCnet-ISA based cards can just get the data-sheet
  from AMD. Call our literature    distribution center at [phone] and
  ask for the Am79C960,    PCnet-ISA data sheet. It's free.

  A quick way to understand whether the    card is    a `stock' card is to
  just look at it. If it's stock, it should just have one large    chip on
  it, a    crystal, a small IEEE address PROM, possibly a socket for a boot
  ROM, and a connector (1, 2, or 3, depending on the media options
  offered). Note that if it's a    coax card, it will have    some transceiver
  stuff    built onto it as well, but that    should be near the connector and
  away from the    PCnet-ISA.'

  There    is also    some info regarding the    LANCE chip in the file lance.c
  which    is included in the standard kernel.

  A note to would-be card hackers is that different LANCE
  implementations do `restart' in different ways. Some pick up where
  they left off    in the ring, and others    start right from the beginning
  of the ring, as if just initialised. This is a concern when setting
  the multicast    list.


  7.9.    Multicast and Promiscuous Mode


  Another one of the things Donald has worked on is implementing
  multicast and    promiscuous mode hooks.     All of    the released (i.e. not
  ALPHA) ISA drivers now support promiscuous mode. There was a minor
  problem with 8390 based cards    with capturing multicast packets, in
  that the promiscuous mode setting in 8390.c around line 574 should be
  0x18 and not 0x10. If    you have an up to date kernel, this will already
  be fixed.

  Donald writes: `At first I was planning to do    it while implementing
  either the /dev/* or DDI interface, but that's not really the    correct
  way to do it.    We should only enable multicast    or promiscuous modes
  when something wants to look at the packets, and shut    it down    when
  that application is finished,    neither    of which is strongly related to
  when the hardware is opened or released.

  I'll start by    discussing promiscuous mode, which is conceptually easy
  to implement.    For most hardware you only have    to set a register bit,
  and from then    on you get every packet    on the wire. Well, it's    almost
  that easy; for some hardware you have    to shut    the board (potentially
  dropping a few packet), reconfigure it, and then re-enable the
  ethercard. This is grungy and    risky, but the alternative seems to be
  to have every    application register before you    open the ethercard at
  boot-time.

  OK, so that's    easy, so I'll move on something    that's not quite so
  obvious: Multicast. It can be    done two ways:


  1. Use promiscuous mode, and a packet    filter like the    Berkeley packet
     filter (BPF). The BPF is a    pattern    matching stack language, where
     you write a program that picks out    the addresses you are interested
     in. Its advantage is that it's very general and programmable. Its
     disadvantage is that there    is no general way for the kernel to
     avoid turning on promiscuous mode and running every packet    on the
     wire through every    registered packet filter. See ``The Berkeley
     Packet Filter'' for more info.


  2. Using the built-in    multicast filter that most etherchips have.

  I guess I should list    what a few ethercards/chips provide:



      Chip/card  Promiscuous  Multicast filter
      ----------------------------------------
      Seeq8001/3c501  Yes      Binary filter    (1)
      3Com/3c509      Yes      Binary filter    (1)
      8390          Yes      Autodin II six bit hash (2) (3)
      LANCE          Yes      Autodin II six bit hash (2) (3)
      i82586      Yes      Hidden Autodin II six    bit hash (2) (4)





  1. These cards claim to have a filter, but it's a simple yes/no
     `accept all multicast packets', or    `accept    no multicast packets'.

  2. AUTODIN II    is the standard    ethernet CRC (checksum)    polynomial. In
     this scheme multicast addresses are hashed    and looked up in a hash
     table. If the corresponding bit is    enabled, this packet is
     accepted. Ethernet    packets    are laid out so    that the hardware to do
     this is trivial --    you just latch six (usually) bits from the CRC
     circuit (needed anyway for    error checking)    after the first    six
     octets (the destination address), and use them as an index    into the
     hash table    (six bits -- a 64-bit table).


  3. These chips use the six bit hash, and must    have the table computed
     and loaded    by the host. This means    the kernel must    include    the CRC
     code.


  4. The 82586 uses the    six bit    hash internally, but it    computes the
     hash table    itself from a list of multicast    addresses to accept.
  Note that none of these chips    do perfect filtering, and we still need
  a middle-level module    to do the final    filtering. Also    note that in
  every    case we    must keep a complete list of accepted multicast
  addresses to recompute the hash table    when it    changes.

  My first pass    at device-level    support    is detailed in the new outline
  driver skeleton.c

  It looks like    the following:


  ______________________________________________________________________
      #ifdef HAVE_MULTICAST
      static void set_multicast_list(struct    device *dev, int num_addrs,
               void    *addrs);
      #endif
      .
      .

      ethercard_open() {
      ...
      #ifdef HAVE_MULTICAST
          dev->set_multicast_list = &set_multicast_list;
      #endif
      ...

      #ifdef HAVE_MULTICAST
      /* Set or clear the multicast    filter for this    adaptor.
         num_addrs -- -1      Promiscuous mode, receive all    packets
         num_addrs -- 0      Normal mode, clear multicast list
         num_addrs > 0      Multicast mode, receive normal and
          MC packets, and do best-effort filtering.
       */
      static void
      set_multicast_list(struct device *dev, int num_addrs,    void *addrs)
      {
      ...
  ______________________________________________________________________



  Any comments,    criticism, etc.    are welcome.'


  7.10.     The Berkeley Packet Filter (BPF)


  The general idea of the developers is    that the BPF functionality
  should not be    provided by the    kernel,    but should be in a (hopefully
  little-used) compatibility library.

  For those not    in the know: BPF (the Berkeley Packet Filter) is an
  mechanism for    specifying to the kernel networking layers what    packets
  you are interested in. It's implemented as a specialized stack
  language interpreter built into a low    level of the networking    code. An
  application passes a program written in this language    to the kernel,
  and the kernel runs the program on each incoming packet. If the kernel
  has multiple BPF applications, each program is run on    each packet.

  The problem is that it's difficult to    deduce what kind of packets the
  application is really    interested in from the packet filter program, so
  the general solution is to always run    the filter. Imagine a program
  that registers a BPF program to pick up a low    data-rate stream sent to
  a multicast address.    Most ethernet cards have a hardware multicast
  address filter implemented as    a 64 entry hash    table that ignores most
  unwanted multicast packets, so the capability    exists to make this a
  very inexpensive operation. But with the BFP the kernel must switch
  the interface    to promiscuous mode, receive _all_ packets, and    run them
  through this filter. This is work, BTW, that's very difficult    to
  account back to the process requesting the packets.


  8.  Networking with a    Laptop/Notebook    Computer


  There    are currently only a few ways to put your laptop on a network.
  You can use the SLIP code (and run at    serial line speeds); you can buy
  one of the few laptops that come with    a NE2000-compatible ethercard;
  you can get a    notebook with a    supported PCMCIA slot built-in;    you can
  get a    laptop with a docking station and plug in an ISA ethercard; or
  you can use a    parallel port Ethernet adapter such as the D-Link
  DE-600.


  8.1.    Using SLIP


  This is the cheapest solution, but by    far the    most difficult.    Also,
  you will not get very    high transmission rates. Since SLIP is not
  really related to ethernet cards, it will not    be discussed further
  here.    See the    NET-2 Howto.


  8.2.    Built in NE2000


  This solution    severely limits    your laptop choices and    is fairly
  expensive. Be    sure to    read the specifications    carefully, as you may
  find that you    will have to buy an additional non-standard transceiver
  to actually put the machine on a network. A good idea    might be to boot
  the notebook with a kernel that has ne2000 support, and make sure it
  gets detected    and works before you lay down your cash.



  8.3.    PCMCIA Support


  As this area of Linux    development is fairly young, I'd suggest that
  you join the LAPTOPS mailing channel.    See ``Mailing lists...''  which
  describes how    to join    a mailing list channel.

  Try and determine exactly what hardware you have (ie.    card
  manufacturer,    PCMCIA chip controller manufacturer) and then ask on the
  LAPTOPS channel. Regardless, don't expect things to be all that
  simple.  Expect to have to fiddle around a bit, and patch kernels,
  etc.    Maybe someday you will be able to type `make config' 8-)

  At present, the two PCMCIA chipsets that are supported are the
  Databook TCIC/2 and the intel    i82365.

  There    is a number of programs    on tsx-11.mit.edu in
  /pub/linux/packages/laptops/ that you    may find useful. These range
  from PCMCIA Ethercard    drivers    to programs that communicate with the
  PCMCIA controller chip. Note that these drivers are usually tied to a
  specific PCMCIA chip (ie. the    intel 82365 or the TCIC/2)

  For NE2000 compatible    cards, some people have    had success with just
  configuring the card under DOS, and then booting linux from the DOS
  command prompt via loadlin.


  For those that are net-surfing you can try:

  Don's    PCMCIA Stuff (http://cesdis.gsfc.nasa.gov/linux/pcmcia.html)

  Anyway, the PCMCIA driver problem isn't specific to the Linux    world.
  It's been a real disaster in the MS-DOS world. In that world people
  expect the hardware to work if they just follow the manual.  They
  might    not expect it to interoperate with any other hardware or
  software, or operate optimally, but they do expect that the software
  shipped with the product will    function. Many PCMCIA adaptors don't
  even pass this test.

  Things are looking up    for Linux users    that want PCMCIA support, as
  substantial progress is being    made. Pioneering this effort is    David
  Hinds. His latest PCMCIA support package can be obtained from    cb-
  iris.stanford.edu in the directory /pub/pcmcia/. Look    for a file like
  pcmcia-cs-X.Y.Z.tgz where X.Y.Z will be the latest version number.
  This is most likely uploaded to tsx-11.mit.edu as well.

  Note that Donald's PCMCIA enabler works as a user-level process, and
  David    Hinds' is a kernel-level solution.  You    may be best served by
  David's package as it    is much    more widely used.


  8.4.    ISA Ethercard in the Docking Station.


  Docking stations for laptops typically cost about $250 and provide two
  full-size ISA    slots, two serial and one parallel port. Most docking
  stations are powered off of the laptop's batteries, and a few    allow
  adding extra batteries in the    docking    station    if you use short ISA
  cards. You can add an    inexpensive ethercard and enjoy    full-speed
  ethernet performance.


  8.5.    Pocket / parallel port adaptors.


  The `pocket' ethernet    adaptors may also fit your need.  Until    recently
  they actually    costed more than a docking station and cheap ethercard,
  and most tie you down    with a wall-brick power    supply.     At present, you
  can choose from the D-Link, or the RealTek adaptor.  Most other
  companies, especially    Xircom,    (see ``Xircom'') treat the programming
  information as a trade secret, so support will likely    be slow    in
  coming. (if ever!)

  Note that the    transfer speed will not    be all that great (perhaps
  100kB/s tops?) due to    the limitations    of the parallel    port interface.

  See ``DE-600 / DE-620'' and ``RealTek'' for supported    pocket adaptors.

  You can sometimes avoid the wall-brick with the adaptors by buying or
  making a cable that draws power from the laptop's keyboard port. (See
  ``keyboard power'')


  9.  Frequently Asked Questions


  Here are some    of the more frequently asked questions about using Linux
  with an Ethernet connection. Some of the more    specific questions are
  sorted on a `per manufacturer    basis'.     However, since    this document is
  basically `old' by the time you get it, any `new' problems will not
  appear here instantly. For these, I suggest that you make efficient
  use of your newsreader. For example, nn users    would type

       nn -xX -s'3c'


  to get all the news articles in your subscribed list that have `3c' in
  the subject. (ie. 3com, 3c509, 3c503,    etc.)  The moral: Read the man
  page for your    newsreader.


  9.1.    Alpha Drivers -- Getting and Using them


  I heard that there is    an alpha driver    available for my card.    Where
  can I    get it?

  The newest of    the `new' drivers can be found on Donald's new ftp site:
  cesdis.gsfc.nasa.gov in the /pub/linux/ area.    Things change here quite
  frequently, so just look around for it.  There is still all the stuff
  on the old ftp site ftp.super.org in /pub/linux, but this is not being
  actively maintained, and hence will be of limited value to most
  people.

  As of    recent v1.1 kernels, the `useable' alpha drivers have been
  included in the standard kernel source tree. When running make config
  you will be asked if you want    to be offered ALPHA test drivers.

  Now, if it really is an alpha, or pre-alpha driver, then please treat
  it as    such. In other words, don't complain because you can't figure
  out what to do with it. If you can't figure out how to install it,
  then you probably shouldn't be testing it.  Also, if it brings your
  machine down,    don't complain.    Instead, send us a well    documented bug
  report, or even better, a patch!

  People reading this while net-surfing    may want to check out:

  Don's    Linux Home Page
  (http://cesdis.gsfc.nasa.gov/pub/linux/linux.html)

  for the latest dirt on what is new and upcoming.


  9.2.    Using More than    one Ethernet Card per Machine


  What needs to    be done    so that    Linux can run two ethernet cards?

  The hooks for    multiple ethercards are    all there.  However, note that
  only one ethercard is    auto-probed for    by default.  This avoids a lot
  of possible boot time    hangs caused by    probing    sensitive cards.

  There    are two    ways that you can enable auto-probing for the second
  (and third, and...) card. The    easiest    method is to pass boot-time
  arguments to the kernel, which is usually done by LILO.Probing for the
  second card can be achieved by using a boot-time argument as simple as
  ether=0,0,eth1. In this case eth0 and    eth1 will be assigned in the
  order    that the cards are found at boot.  Say if you want the card at
  0x300    to be eth0 and the card    at 0x280 to be eth1 then you could use


       LILO: linux ether=5,0x300,eth0 ether=15,0x280,eth1


  The ether= command accepts more than the IRQ + i/o + name shown above.
  Please have a    look at    ``Passing Ethernet Arguments...''  for the full
  syntax, card specific    parameters, and    LILO tips.


  These    boot time arguments can    be made    permanent so that you don't have
  to re-enter them every time. See the LILO configuration option
  `append' in the LILO manual.

  The second way (not recommended) is to edit the file Space.c and
  replace the 0xffe0 entry for the i/o address with a zero. The    0xffe0
  entry    tells it not to    probe for that device -- replacing it with a
  zero will enable autoprobing for that    device.     If you    really need more
  than four ethernet cards in one machine, then    you can    clone the eth3
  entry    and change eth3    to eth4.

  Note that if you are intending to use    Linux as a gateway between two
  networks, you    will have to re-compile    a kernel with IP forwarding
  enabled. Usually using an old    AT/286 with something like the `kbridge'
  software is a    better solution.

  If you are viewing this while    net-surfing, you may wish to look at a
  mini-howto Donald has    on his WWW site. Check out Multiple Ethercards
  (http://cesdis.gsfc.nasa.gov/linux/misc/multicard.html).


  9.3.    Problems with NE1000 / NE2000 cards (and clones)


  Problem: NE*000 ethercard at 0x360 doesn't get detected anymore.

  Reason: Recent kernels ( > 1.1.7X) have more sanity checks with
  respect to overlapping i/o regions. Your NE2000 card is 0x20 wide in
  i/o space, which makes it hit    the parallel port at 0x378.  Other
  devices that could be    there are the second floppy controller (if
  equipped) at 0x370 and the secondary IDE controller at 0x376--0x377.
  If the port(s) are already registered    by another driver, the kernel
  will not let the probe happen.

  Solution: Either move    your card to an    address    like 0x280, 0x340, 0x320
  or compile without parallel printer support.

  Problem: Network `goes away' every time I print something (NE2000)

  Reason: Same problem as above, but you have an older kernel that
  doesn't check    for overlapping    i/o regions. Use the same fix as above,
  and get a new    kernel while you are at    it.

  Problem: NE*000 ethercard probe at 0xNNN: 00 00 C5 ... not found.
  (invalid signature yy    zz)

  Reason: First    off, do    you have a NE1000 or NE2000 card at the    addr.
  0xNNN?  And if so, does the hardware address reported    look like a
  valid    one? If    so, then you have a poor NE*000    clone. All NE*000 clones
  are supposed to have the value 0x57 in bytes 14 and 15 of the    SA PROM
  on the card. Yours doesn't --    it has `yy zz' instead.

  Solution: The    driver (/usr/src/linux/drivers/net/ne.c) has a "Hall of
  Shame" list at about line 42.    This list is used to detect poor clones.
  For example, the DFI cards use `DFI' in the first 3 bytes of the prom,
  instead of using 0x57    in bytes 14 and    15, like they are supposed to.

  You can determine what the first 3 bytes of your card    PROM are by
  adding a line    like:


      printk("PROM prefix: %#2x    %#2x %#2x\n",SA_prom[0],SA_prom[1],SA_prom[2]);




  into the driver, right after the error message you got above,    and just
  before the "return ENXIO" at line 227.

  Reboot with this change in place, and    after the detection fails, you
  will get the three bytes from    the PROM like the DFI example above.
  Then you can add your    card to    the bad_clone_list[] at    about line 43.
  Say the above    line printed out:


       PROM prefix: 0x3F 0x2D 0x1C


  after    you rebooted. And say that the 8 bit version of    your card was
  called the "FOO-1k" and the 16 bit version the "FOO-2k". Then    you
  would    add the    following line to the bad_clone_list[]:


       {"FOO-1k", "FOO-2k", {0x3F, 0x2D, 0x1C,}},


  Note that the    2 name strings you add can be anything -- they are just
  printed at boot, and not matched against anything on the card.  You
  can also take    out the    "printk()" that    you added above, if you    want.
  It shouldn't hit that    line anymore anyway. Then recompile once more,
  and your card    should be detected.

  Problem: Errors like DMA address mismatch

  Is the chip a    real NatSemi 8390? (DP8390, DP83901, DP83902 or
  DP83905)?  If    not, some clone    chips don't correctly implement    the
  transfer verification    register. MS-DOS drivers never do error
  checking, so it doesn't matter to them.

  Are most of the messages off by a factor of 2?  If so:  Are you using
  the NE2000 in    a 16 bit slot?    Is it jumpered to use only 8 bit
  transfers?

  The Linux driver expects a NE2000 to be in a 16 bit slot. A NE1000 can
  be in    either size slot. This problem can also    occur with some    clones,
  notably D-Link 16 bit    cards, that don't have the correct ID bytes in
  the station address PROM.

  Are you running the bus faster than 8Mhz?  If    you can    change the speed
  (faster or slower), see if that makes    a difference. Most NE2000 clones
  will run at 16MHz, but some may not. Changing    speed can also mask a
  noisy    bus.

  What other devices are on the    bus?  If moving    the devices around
  changes the reliability, then    you have a bus noise problem --    just
  what that error message was designed to detect. Congratulations,
  you've probably found    the source of other problems as    well.

  Problem: The machine hangs during boot right after the `8390...'  or
  `WD....' message. Removing the NE2000    fixes the problem.

  Solution: Change your    NE2000 base address to 0x340. Alternatively, you
  can use the device registrar implemented in 0.99pl13 and later
  kernels.

  Reason: Your NE2000 clone isn't a good enough    clone. An active NE2000
  is a bottomless pit that will    trap any driver    autoprobing in its
  space. The other ethercard drivers take great    pain to    reset the NE2000
  so that it's safe, but some clones cannot be reset. Clone chips to
  watch    out for: Winbond 83C901. Changing the NE2000 to    a less-popular
  address will move it out of the way of other autoprobes, allowing your
  machine to boot.
  Problem: The machine hangs during the    SCSI probe at boot.

  Reason: It's the same    problem    as above, change the ethercard's
  address, or use the device registrar.

  Problem: The machine hangs during the    soundcard probe    at boot.

  Reason: No, that's really during the silent SCSI probe, and it's the
  same problem as above.

  Problem: Errors like eth0: DMAing conflict in    ne_block_input

  This bug came    from timer-based packet    retransmissions. If you    got a
  timer    tick _during_ a    ethercard RX interrupt,    and timer tick tried to
  retransmit a timed-out packet, you could get a conflict. Because of
  the design of    the NE2000 you would have the machine hang (exactly the
  same the NE2000-clone    boot hangs).

  Early    versions of the    driver disabled    interrupts for a long time, and
  didn't have this problem. Later versions are fixed. (ie. kernels after
  0.99p9 should    be OK.)

  Problem: NE2000 not detected at boot - no boot messages at all

  Donald writes: `A few    people have reported a problem with detecting
  the Accton NE2000.  This problem occurs only at boot-time, and the
  card is later    detected at run-time by    the identical code my (alpha-
  test)    ne2k diagnostic    program. Accton    has been very responsive, but I
  still    haven't    tracked    down what is going on. I've been unable    to
  reproduce this problem with the Accton cards we purchased. If    you are
  having this problem, please send me an immediate bug report. For that
  matter, if you have an Accton    card send me a success report, including
  the type of the motherboard. I'm especially interested in finding out
  if this problem moves    with the particular ethercard, or stays    with the
  motherboard.'

  Here are some    things to try, as they have fixed it for some people:


  o  Change the    bus speed, or just move    the card to a different    slot.

  o  Change the    `I/O recovery time' parameter in the BIOS chipset
     configuration.


  9.4.    Problems with WD80*3 cards


  Problem: A WD80*3 is falsely detected. Removing the sound or MIDI card
  eliminates the `detected' message.

  Reason: Some MIDI ports happen to produce the    same checksum as a WD
  ethercard.

  Solution: Update your    ethercard driver: new versions include an
  additional sanity check. If it is the    midi chip at 0x388 that    is
  getting detected as a    WD living at 0x380, then you could also    use:

      LILO:    linux reserve=0x380,8



  Problem: You get messages such as the    following with your 80*3:



  eth0:    bogus packet size, status = ........  kmalloc called with impos-
  sibly    large argument (65400) eth0: Couldn't allocate sk_buff of size
  65400    eth0: receiver overrun


  Reason: There    is a shared memory problem.

  Solution: If the problem is sporadic,    you have hardware problems.
  Typical problems that    are easy to fix    are board conflicts, having
  cache    or `shadow ROM'    enabled    for that region, or running your bus
  faster than 8Mhz. There are also a surprising    number of memory
  failures on ethernet cards, so run a diagnostic program if you have
  one for your ethercard.

  If the problem is continual, and you have have to reboot to fix the
  problem, record the boot-time    probe message and mail it to
  [e-mail] -    Take particular    note of    the shared
  memory location.

  Problem: WD80*3 will not get detected    at boot.

  Reason: Earlier versions of the Mitsumi CD-ROM (mcd) driver probe at
  0x300    will succeed if    just about anything is that I/O    location.  This
  is bad news and needs    to be a    bit more robust.  Once another driver
  registers that it `owns' an I/O location, other drivers (incl. the
  wd80x3) are `locked out' and can not probe that addr for a card.

  Solution: Recompile a    new kernel without any excess drivers that you
  aren't using,    including the above mcd    driver.     Or try    moving your
  ethercard to a new I/O addr. Valid I/O addr. for all the cards are
  listed in ``Probed Addresses'' You can also point the    mcd driver off
  in another direction by a boot-time parameter    (via LILO) such    as:

       mcd=0x200,12


  Problem: Old wd8003 and/or jumper-settable wd8013 always get the IRQ
  wrong.

  Reason: The old wd8003 cards and jumper-settable wd8013 clones don't
  have the EEPROM that the driver can read the IRQ setting from.  If the
  driver can't read the    IRQ, then it tries to auto-IRQ to find out what
  it is. And if    auto-IRQ returns zero, then the    driver just assigns IRQ
  5 for    an 8 bit card or IRQ 10    for a 16 bit card.

  Solution: Avoid the auto-IRQ code, and tell the kernel what the IRQ
  that you have    jumpered the card to is    via a boot time    argument.  For
  example, if you are using IRQ    9, using the following should work.


       LILO: linux ether=9,0,eth0



  9.5.    Problems with 3Com cards

  Problem: The 3c503 picks IRQ N, but this is needed for some other
  device which needs IRQ N. (eg. CD ROM    driver,    modem, etc.)  Can this
  be fixed without compiling this into the kernel?

  Solution: The    3c503 driver probes for    a free IRQ line    in the order {5,
  9/2, 3, 4}, and it should pick a line    which isn't being used.    Very old
  drivers used to pick the IRQ line at boot-time, and the current driver
  (0.99pl12 and    newer) chooses when the    card is    open()/ifconfig'ed.


  Alternately, you can fix the IRQ at boot by passing parameters via
  LILO.    The following selects IRQ9, base location 0x300, <ignored
  value>, and if_port #1 (the external transceiver).


       LILO: linux ether=9,0x300,0,1,eth0


  The following    selects    IRQ3, probes for the base location, <ignored
  value>, and the default if_port #0 (the internal transceiver)


       LILO: linux ether=3,0,0,0,eth0


  Problem: 3c503: Configured interrupt number XX is out    of range.

  Reason: Whoever built    your kernel fixed the ethercard    IRQ at XX.  The
  above    is truly evil, and worse than that, it is not necessary. The
  3c503    will autoIRQ when it gets ifconfig'ed, and pick    one of IRQ{5,
  2/9, 3, 4}.

  Solution: Use    LILO as    described above, or rebuild the    kernel,    enabling
  autoIRQ by not specifying the    IRQ line.

  Problem: The supplied    3c503 drivers don't use    the AUI    (thicknet) port.
  How does one choose it over the default thinnet port?

  Solution: The    3c503 AUI port can be selected at boot-time with
  0.99pl12 and later. The selection is overloaded onto the low bit of
  the currently-unused dev->rmem_start variable, so a boot-time
  parameter of:


       LILO: linux ether=0,0,0,1,eth0


  should work. A boot line to force IRQ    5, port    base 0x300, and    use an
  external transceiver is:


       LILO: linux ether=5,0x300,0,1,eth0


  Also note that kernel    revisions 1.00 to 1.03 had an interesting
  `feature'. They would    switch to the AUI port when the    internal
  transciever failed. This is a    problem, as it will never switch back if
  for example you momentarily disconnect the cable. Kernel versions 1.04
  and newer only switch    if the very first Tx attempt fails.


  9.6.    Problems with Hewlett Packard Cards


  Problem: HP Vectra using built in AMD    LANCE chip gets    IRQ and    DMA
  wrong.

  Solution: The    HP Vectra uses a different implementation to the
  standard HP-J2405A. The `lance.c' driver used    to always use the value
  in the setup register    of an HP Lance implementation.    In the Vectra
  case it's reading an invalid 0xff value. Kernel versions newer than
  about    1.1.50 now handle the Vectra in    an appropriate fashion.

  Problem: HP Card is not detected at boot, even though    kernel was
  compiled with    `HP PCLAN support'.

  Solution: You    probably have a    HP PCLAN+  -- note the `plus'. Support
  for the PCLAN+ was added to final versions of    1.1, but some of them
  didn't have the entry    in `config.in'.    If you have the    file hp-plus.c
  in  /linux/drivers/net/ but no entry in config.in, then add the
  following line under the `HP PCLAN support' line:


      bool 'HP PCLAN Plus support' CONFIG_HPLAN_PLUS n



  Kernels up tp    1.1.54 are missing the line in `config.in' still.  Do a
  `make    mrproper;make config;make dep;make zlilo' and you should be in
  business.


  9.7.    FAQs Not Specific to Any Card.



  9.7.1.  ifconfig reports the wrong i/o address for the card.


  No it    doesn't. You are just interpreting it incorrectly.  This is not
  a bug, and the numbers reported are correct. It just happens that some
  8390 based cards (wd80x3, smc-ultra, etc) have the actual 8390 chip
  living at an offset from the first assigned i/o port.     Try cd
  /usr/src/linux/drivers/net;grep NIC_OFFSET *.c|more to see what is
  going    on. This is the    value stored in    dev->base_addr,    and is what
  ifconfig reports. If you want    to see the full    range of ports that your
  card uses, then try cat /proc/ioports    which will give    the numbers you
  expect.


  9.7.2.  Token    Ring

  Is there token ring support for Linux?

  To support token ring    requires more than only    a writing a device
  driver, it also requires writing the source routing routines for token
  ring.    It is the source routing that would be the most    time comsuming
  to write.

  Alan Cox adds: `It will require (...)    changes    to the bottom socket
  layer    to support 802.2 and 802.2 based TCP/IP. Don't expect anything
  soon.'

  Peter    De Schrijver has been spending some time on Token Ring lately,
  and has patches that are available for IBM ISA and MCA token ring
  cards. Don't expect miracles here, as    he has just started on this as
  of 1.1.42. You can get the patch from:

  aix13ps2.cc.kuleuven.ac.be:/pub/Linux/TokenRing.patch-1.1.49.gz



  9.7.3.  32 Bit / VLB / PCI Ethernet Cards


  What is the selection    for 32 bit ethernet cards?

  There    aren't many 32 bit ethercard device drivers because there aren't
  that many 32 bit ethercards.

  There    aren't many 32 bit ethercards out there    because    a 10Mbs    network
  doesn't justify spending the 5x price    increment for the 32 bit
  interface.  See ``Programmed I/O vs. ...'' as    to why having an
  ethercard on an 8MHz ISA bus is really not a bottleneck.

  This might change now    that AMD has introduced    the 32 bit PCnet-VLB and
  PCnet-PCI chips.  The    street price of    the Boca PCnet-VLB board should
  be under $70 from a place like CMO (see Computer Shopper).  See ``Boca
  PCI/VLB'' for    info on    these cards.

  See ``AMD PCnet-32'' for info    on the 32 bit versions of the LANCE /
  PCnet-ISA chip.

  The DEC 21040    PCI chip is another option (see    ``DEC 21040'') for
  power-users.    The 21140 100Base-? chip could prove interesting as
  well,    as it is supposedly driver compatible with the 21040. Should be
  good for uncovering any race-conditions, if nothing else...


  9.7.4.  FDDI

  Is there FDDI    support    for Linux?

  Donald writes: `No, there is no Linux    driver for any FDDI boards.  I
  come from a place with supercomputers, so an external    observer might
  think    FDDI would be high on my list. But FDDI    never delivered    end-to-
  end throughput that would justify its    cost, and it seems to be a
  nearly abandoned technology now that 100base{X,Anynet} seems imminent.
  (And yes, I know you can now get FDDI    boards for <$1K. That seems to
  be a last-ditch effort to get    some return on the development
  investment. Where is the next    generation of FDDI going to come from?)'


  9.7.5.  Linking 10BaseT without a Hub


  Can I    link 10BaseT (RJ45) based systems together without a hub?

  You can link 2 machines easily, but no more than that, without extra
  devices/gizmos. See ``Twisted    Pair'' -- it explains how to do    it. And
  no, you can't    hack together a    hub just by crossing a few wires and
  stuff. It's pretty much impossible to    do the collision signal    right
  without duplicating a    hub.


  9.7.6.  SIOCSFFLAGS: Try again


  I get    `SIOCSFFLAGS: Try again' when I    run `ifconfig' -- Huh?

  Some other device has    taken the IRQ that your    ethercard is trying to
  use, and so the ethercard can't use the IRQ.    You don't necessairly
  need to reboot to resolve this, as some devices only grab the    IRQs
  when they need them and then release them when they are done.    Examples
  are some sound cards,    serial ports, floppy disk driver, etc. You can
  type cat /proc/interrupts to see which interrupts are    presently in
  use. Most of the Linux ethercard drivers only    grab the IRQ when they
  are opened for use via `ifconfig'. If    you can    get the    other device to
  `let go' of the required IRQ line, then you should be    able to    `Try
  again' with ifconfig.


  9.7.7.  Link UNSPEC and HW-addr of 00:00:00:00:00:00


  When I run ifconfig with no arguments, it reports that LINK is UNSPEC
  (instead of 10Mbs Ethernet) and it also says that my hardware    address
  is all zeros.
  This is because people are running a newer version of    the `ifconfig'
  program than their kernel version. This new version of ifconfig is not
  able to report these properties when used in conjunction with    an older
  kernel. You can either upgrade your kernel, `downgrade' ifconfig, or
  simply ignore    it. The    kernel knows your hardware address, so it really
  doesn't matter if ifconfig can't read    it.


  9.7.8.  Huge Number of RX and    TX Errors


  When I run ifconfig with no arguments, it reports that I have    a huge
  error    count in both rec'd and    transmitted packets. It    all seems to
  work ok -- What is wrong?

  Look again. It says RX packets big number PAUSE errors 0 PAUSE dropped
  0 PAUSE overrun 0.  And the same for the TX column.  Hence the big
  numbers you are seeing are the total number of packets that your
  machine has rec'd and    transmitted.  If you still find    it confusing,
  try typing cat /proc/net/dev instead.


  9.7.9.  Entries in /dev/ for Ethercards


  I have /dev/eth0 as a    link to    /dev/xxx. Is this right?

  Contrary to what you have heard, the files in    /dev/* are not used.
  You can delete any /dev/wd0, /dev/ne0    and similar entries.


  9.7.10.  Linux and ``trailers''


  Should I disable trailers when I `ifconfig' my ethercard?

  You can't disable trailers, and you shouldn't    want to. `Trailers' are
  a hack to avoid data copying in the networking layers. The idea was to
  use a    trivial    fixed-size header of size `H', put the variable-size
  header info at the end of the    packet,    and allocate all packets `H'
  bytes    before the start of a page. While it was a good    idea, it turned
  out to not work well in practice.  If    someone    suggests the use of
  `-trailers', note that it is the equivalent of sacrificial goats
  blood. It won't do anything to solve the problem, but    if problem fixes
  itself then someone can claim    deep magical knowledge.


  9.7.11.  Non-existent    Apricot    NIC is detected


  I get    eth0: Apricot 82596 at 0x300, 00 00 00 00 00 00    IRQ 10 and
  apricot.c:v.0.02 19/05/94 when I boot, but I don't have an
  ``Apricot''. And then    the card I do have isn't detected.

  A few    kernel releases    had a version of the Apricot driver which only
  used a simple    checksum to detect if an Apricot is present. This would
  mistakenly think that    almost everything was an Apricot NIC. It really
  should look at the vendor prefix instead. However there is now a check
  to see if the    hardware address is all    zeros, so this shouldn't happen.
  Your choices are to move your    card off of 0x300 (the only place the
  Apricot driver probes), or better yet, get a new kernel.





  10.  Miscellaneous.


  Any other associated stuff that didn't fit in    anywhere else gets
  dumped here. It may not be relevant, and it may not be of general
  interest but it is here anyway.


  10.1.     Passing Ethernet Arguments to the Kernel


  Here are two generic kernel commands    that can be passed to the kernel
  at boot time.    This can be done with LILO, loadlin, or    any other
  booting utility that accepts optional    arguments.

  For exmaple, if the command was `blah' and it    expected 3 arguments
  (say 123, 456, and 789) then,    with LILO, you would use:

  LILO:    linux blah=123,456,789

  Note:    PCI cards have their i/o and IRQ assigned by the BIOS at boot.
  This means that any boot time    arguments for a    PCI card's IRQ or i/o
  ports    are ignored.


  10.1.1.  The ether command


  In its most generic form, it looks something like this:


       ether=IRQ,BASE_ADDR,PARAM_1,PARAM_2,NAME


  All arguments    are optional.  The first non-numeric argument is taken
  as the NAME.

  IRQ: Obvious.     An IRQ    value of `0' (usually the default) means to
  autoIRQ.  It's a historical accident that the    IRQ setting is first
  rather than the base_addr -- this will be fixed whenever something
  else changes.

  BASE_ADDR: Also obvious.  A value of `0' (usually the    default) means
  to probe a card-type-specific    address    list for an ethercard.

  PARAM_1: It was orginally used as an override    value for the memory
  start    for a shared-memory ethercard, like the    WD80*3.     Some drivers
  use the low four bits    of this    value to set the debug message level.  0
  -- default, 1-7 -- level 1..7, (7 is maximum verbosity)  8 --    level 0
  (no messages). Also, the LANCE driver    uses the low four bits of this
  value    to select the DMA channel.  Otherwise it uses auto-DMA.

  PARAM_2: The 3c503 driver uses this to select    between    the internal and
  external transceivers.  0 -- default/internal, 1 -- AUI external.  The
  Cabletron E21XX card also uses the low 4 bits    of PARAM_2 to select the
  output media.    Otherwise it detects automatically.

  NAME:    Selects    the network device the values refer to.     The standard
  kernel uses the names    `eth0',    `eth1',    `eth2' and `eth3' for bus-
  attached ethercards, and `atp0' for the parallel port    `pocket'
  ethernet adaptor. The    arcnet driver uses `arc0' as its name.    The
  default setting is for a single ethercard to be probed for as    `eth0'.
  Multiple cards can only be enabled by    explicitly setting up their base
  address using    these LILO parameters.    The 1.0    kernel has LANCE-based
  ethercards as    a special case.     LILO arguments    are ignored, and LANCE
  cards    are always assigned `eth<n>' names starting at `eth0'.
  Additional non-LANCE ethercards must be explicitly assigned to
  `eth<n+1>', and the usual `eth0' probe disabled with something like
  `ether=0,-1,eth0'.  (    Yes, this is bug. )


  10.1.2.  The reserve command


  This next lilo command is used just like `ether=' above, ie. it is
  appended to the name of the boot select specified in lilo.conf


       reserve=IO-base,extent{,IO-base,extent...}


  In some machines it may be necessary to prevent device drivers from
  checking for devices (auto-probing) in a specific region. This may be
  because of poorly designed hardware that causes the boot to freeze
  (such    as some    ethercards), hardware that is mistakenly identified,
  hardware whose state is changed by an    earlier    probe, or merely
  hardware you don't want the kernel to    initialize.

  The reserve boot-time    argument addresses this    problem    by specifying an
  I/O port region that shouldn't be probed. That region    is reserved in
  the kernel's port registration table as if a device has already been
  found    in that    region.    Note that this mechanism shouldn't be necessary
  on most machines. Only when there is a problem or special case would
  it be    necessary to use this.

  The I/O ports    in the specified region    are protected against device
  probes. This was put in to be    used when some driver was hanging on a
  NE2000, or misidentifying some other device as its own.  A correct
  device driver    shouldn't probe    a reserved region, unless another boot
  argument explicitly specifies    that it    do so.    This implies that
  reserve will most often be used with some other boot argument. Hence
  if you specify a reserve region to protect a specific    device,    you must
  generally specify an explicit    probe for that device. Most drivers
  ignore the port registration table if    they are given an explicit
  address.

  For example, the boot    line


       LILO: linux  reserve=0x300,32  ether=0,0x300,eth0


  keeps    all device drivers except the ethercard    drivers    from probing
  0x300-0x31f.

  As usual with    boot-time specifiers there is an 11 parameter limit,
  thus you can only specify 5 reserved regions per reserve keyword.
  Multiple reserve specifiers will work    if you have an usually
  complicated request.


  10.2.     Using the Ethernet Drivers as Modules


  At present, all the modules are put in the subdirectory modules in
  your Linux kernel source tree    (usually in the    form of    symbolic links).
  To actually generate the modules, you    have to    type make modules after
  you have finished building the kernel    proper.    Earlier    kernels    built
  them automatically, which wasn't fair    to those compiling on 4MB
  386sx-16 machines.


  If you have an 8390 based card, you will have    to insert two modules,
  8390.o and then the module for your card.  You can find out if your
  card uses an 8390 chip by reading the    above documentation for    your
  card,    or by just typing something like grep 8390 my_card_name.c in the
  drivers/net/ directory. If grep finds    anything, then your card has an
  8390 (or compatible) chip.

  Once you have    figured    this out, you can insert the module(s) by typing
  insmod mod_name.o as root. The command lsmod will show you what
  modules are loaded, and rmmod    will remove them.

  Once a module    is inserted, then you can use it just like normal, and
  give ifconfig    commands. If you set up    your networking    at boot, then
  make sure your /etc/rc* files    run the    insmod command(s) before getting
  to the ifconfig command.

  Also note that a busy    module can't be    removed. That means that you
  will have to ifconfig    eth0 down  (shut down the ethernet card) before
  you can remove the modules. Also, if you use an 8390 based card, you
  will have to remove the card module before removing the 8390 module,
  as the 8390 module is    used by    the card module.


  10.3.     Contributors


  Other    people who have    contributed (directly or indirectly) to    the
  Ethernet-Howto are, in alphabetical order:


      Ross Biro          <[e-mail]>
      Alan Cox          <[e-mail]>
      David    C. Davies      <[e-mail]>
      Bjorn    Ekwall          <[e-mail]>
      David    Hinds          <[e-mail]>
      Michael Hipp          <[e-mail]>
      Mike Jagdis          <[e-mail]>
      Duke Kamstra          <[e-mail]>
      Russell Nelson      <[e-mail]>
      Cameron Spitzer      <[e-mail]>
      Dave Roberts          <[e-mail]>
      Glenn    Talbott          <[e-mail]>




  Many thanks to the above people, and all the other unmentioned testers
  out there.


  10.4.     Closing


  If you have found any    glaring    typos, or outdated info    in this
  document, please let one of us know. It's getting big, and it    is easy
  to overlook stuff.

  Thanks,

  Paul Gortmaker, [e-mail]

  Donald J. Becker, [e-mail]