MIDICraft's MIDINET CD-ROM

home *** CD-ROM | disk | FTP | other *** search

/ MIDICraft's MIDINET CD-ROM / MIDICraft's MIDINET CD-ROM.iso / DOCS / FUNET.ZIP / FUNET.TXT

Wrap

Text File | 1996-10-03 | 27.5 KB | 694 lines

# # doc/README.FTP -- Introduction to nic.funet.fi archive # # Status: Draft # Author: staff@ftp.funet.fi (comments on this doc only) # Created: Sat Aug 22 20:31:58 1992 # Last modified: Thu Apr 11 17:13:42 EET DST 1996 # Welcome to FTP.FUNET.FI aka FINFILES.BITNET For management also: NIC.FUNET.FI This is a DEC-Alpha(AXP) 3000/900 with (22-Apr-95) 70 GB archive disk space (60 GB used). This system is owned by the Finnish Academic and Research Network FUNET, and is located at the Finnish State Computing Centre, near Helsinki, Finland. Paper mail address: FUNET, Archive server managers Tietotie 6, POBOX 405, FIN-02101 Espoo FINLAND This server group has many names. Its "staff" will always be at `nic.funet.fi', but othervice consider using philosophy: `name by function', thus FTP from ftp.funet.fi. NOTE: If you have troubles with multiple intermediate reply lines from FTP server, try prefixing your entry for `Password:' prompt with `-'. If your REAL password in THIS system starts with `-', enter TWO `-' characters. If that does not help, try to use non-standard port this server in an already quieted operation mode: $ ftp ftp> open ftp.funet.fi 621 ... (depending HOW your ftp-client accepts the port definition..) CONTENTS: - Intro - What is considered proper conduct of anonymous FTP usage - Privacy issues - Contacts about material in here ( GIFs and others ) - Uploading - CD-ROMs - FTPD sources - Reporting a bug/problems - Non-standard FTP features ( Dumping subdirectories, compressing files, uncompressing files.. when transfer in action! ) - Physical disk structure is hidden behind logical one - Restrictions - Minimum of maximum retrieval rate - IP-reversal and valid "passwd" requirements - What is `Freely distributable' ? - Other services available from here - Many names of the server INTRO: This system has plenty of freely distributable material on its FTPable areas. We have also other services, see at the end of this document for pointers. If you have any questions regarding MATERIALS in this archive, read first `Contacts about material in here' below. If you can't locate correct person/mail alias with it, try `problems@nic.funet.fi', but do not do that as your only attempt! WHAT IS CONSIDERED A PROPER CONDUCT OF ANONYMOUS FTP USAGE: Like many systems world wide, ours offers anonymous logins for FTP users. Such a service means: - You do not need to apply an account at this server, just use well known userid: anonymous and for a password do enter your email address (in format: your_userid@your_site) - While this service is called "anonymous" due to that well-known userid, it is considered good manners to identify yourself properly. (No, this is not truly anonymous.) (See PRIVACY ISSUES) For those who have this privilege of using ftp, here are some do's and don'ts: - When you are working over long distance links, do limit yourself to off hours. When working between the USA and Finland, try it after 4 PM OUR time ( 10 AM Eastern USA time.) And remember that we wake up 10 hours before California. We are at time zone `GMT +2h'. - 90+% of material in this archive are originated from various locations all over USA. Sometimes those locations are well known. Often not. We try to indicate origins if we know them. DO try to use server nearest (network wise) to yourself, USA folks: please restrain yourself to USA. - When you log in anonymous, system immediately classifies you, and if you are not limited by number of users on your class, you are prompted with: 331 Guest login ok, send ident (your email address) as password. It really means what is says: Give your email address as password. We might spot problems on files and send warnings to those who have requested that(/those) file(s) (see PRIVACY ISSUES). If your FTP program uses getpass(3) routine blindly (most BSD networking source derived FTP programs), you can't enter more than 8 characters for password from the keyboard. Ever. Try to install FTP program from /pub/local/src/net2+mea-ftp.tar.Z. You can then feed in a lot longer `passwords'. (It has replacement for getpass() which inputs 130 chars.) Alternatively, read the man-page of ftp-program (assuming you are using UNIX ftp client), and see what is said about ".netrc". Some machines have problems with @-characters at such addresses, UNIX: stty erase ^? kill ^u IBM VM/SP CMS: CP TERM CHARDEL OFF, CP TERM LINEND OFF - When you upload something, make sure it is freely distributable. For example some GIF images we have gotten are very obviously scanned from magazines, which have publication copyrights on them. This makes it illegal to copy those pictures `without the prior written consent of the publisher.' (And yes, WE WANT TO SEE THAT WRITTEN CONSENT FOR UPLOADING SUCH!) - See below more about what is `Freely Distributable'. After all, it is not always the same as Public Domain! - REMEMBER: USING ANONYMOUS FTP IS A PRIVILEGE. DON'T ABUSE IT! PRIVACY ISSUES All file accesses, logins etc. are logged, and the logs are kept for indefinite period of time pending disk space availability (3-5 months online, years offline.) If you want to be unidentifiable, that is entirely up to you, and possible within rules of our server by using password of type: inconnu@<your host identity> If you want to be totally unknown, you must not use FTP, as it can never be used without revealing your own host ( = machine ) identity. There do exist ftp-by-mail servers, and proxy-ftp-servers, which occasionally do reveal their user identity -- send requesting user's address as password. Some gopher and WWW -gateways are able to reveal only users host identity, which in case of a PC or equivalent can be deduced to one particular user. CONTACTS ABOUT MATERIAL IN HERE: Example: An alias "amiga-adm" is to be addressed as "amiga-adm@ftp.funet.fi" Alias Area Description ============================================================================= 386ix-adm pub/unix/386ix/ 386 UNIX software amiga-adm pub/amiga/ CBM Amiga programs astro-adm pub/astro/ (amateur) Astronomy related material atari-adm pub/atari/ Atari archive cae-sw-adm pub/cae/ Computer Aided Engineering calculators-adm pub/misc/hp* HP etc. programmable calculators cbm-adm pub/cbm/ Commodore micros C-64, VIC-20, ... csc-adm pub/csc/ Centre for Scientific Computing, FI culture-adm pub/culture/ Cultural information doc-adm pub/doc/ Documents dx-adm pub/dx/ DX-listeners etext-adm pub/doc/literary/etext/ Electronic Texts pics-adm pub/pics/ GIF pictures gnu-adm pub/gnu/ GNU material graphics-adm pub/graphics/ Graphics software ham-adm pub/ham/ Radio-Amateur related information icadm pub/ic/ ISODE-consortium OSI distribution pics-adm pub/pics/ JPEG encoded images kermit-adm pub/kermit/ KERMIT languages-adm pub/languages/ Programming languages linux-adm pub/OS/Linux/ Linux mac-adm pub/mac/ Macintosh software mach-adm pub/mach/ Mach microkernel microprocs-adm pub/microprocs/ Microprocessors minix-adm pub/minix/ comp.os.minix archives et.al. misc-adm pub/misc/ Miscellaneous stuff molbio-adm pub/sci/molbio/ Molecular Biology archive msdos-adm pub/msdos MS-DOS and Windows music-adm pub/culture/music/ Music netinfo-adm pub/netinfo/ Networking (old) netinfo-adm pub/networking/ Networking (new) neural-adm pub/sci/neural/ Neural Networks next-adm pub/NeXT/ NeXT Step specific software os2-adm pub/os2/ OS/2 interests papers-adm pub/sci/papers/ Scientific papers sci-adm pub/sci/ Scientific information in general sound-adm pub/sounds/ Audio or sound files tex-adm pub/TeX/ TeX unix-adm pub/unix/ UN*X software etc. vms-adm pub/vms/ VMS software win-nt-adm pub/win-nt/ MS-Windows NT xwindow-adm pub/X11/ X-Window System Specials ======== ftp-bugs FTP server software bug reporting address managers Everything archive related, which isn't proper for all the 100+ area maintainers but just for the system managers (hks and mea). maints All archive maintainers (ONLY AS THE LAST RESORT!) If you can logon (anonymously) and read this file, you probably do not have problems with your/our ftp software, therefore you should contact above mentioned area administrators. If you don't find suitable alias to approach, try: managers@ftp.funet.fi We also have a mail server for - among other things - to manipulate internal mailing lists. You may wish to join to NEWMSDOS list for example: Mail mailserver@ftp.funet.fi Subject: Requesting lists and help help ; Stop here for the first time around, your system MAY have ; problems in its mailer, check that you get any response ; from ftp.funet.fi mailer. Then proceed: list subscribe newmsdos Joe User These will 1) print basic help with pointers for more, 2) give you a list of locally known mailing lists, 3) add you to list NEWMSDOS with real name `Joe User' (use your own name). On overall, this behaves much in style of BITNET LISTSERVs, but as it isn't LISTSERV, it isn't called one either. A WORD OF WARNING: TEST YOUR EMAIL SYSTEM AT FIRST BY SENDING ONLY "help" REQUEST (no "list", nor "subscribe"). This to avoid our postmaster getting bounces because your address didn't work... There are at least following "NEW"-lists: NEWMSDOS, NEWMAC, NEWAMIGA, NEWAMINET UPLOADING: See file /README.UPLOADER for detailed procedure and explanations. For short: there are directories that are world writable, BUT THIS SYSTEM DOES NOT LET UPLOADED FILES TO BE VISIBLE/RETRIEVABLE BEFORE AREA-MAINTAINERS CHECK AND APPROVE THEM. What we expect uploader to do when uploading anything is stated in /README.UPLOADER. Read it! You may log into the system without being limited by the foreign user count, if you use account "uploader" instead of "anonymous". Rules are still the same regarding the password. CD-ROMs [ this chapter bases on old data -- of Aug-93.. we have grown since then.. ] Every now and then we are asked for a CD-ROM of this archive; so far there are none available with the exception of the Euroscene 1 collection based on part of the Amiga area. We don't expect many exceptions... Reasons for this are multiple, not the least of them being our unwillingess to do the effort of publishing such a set. Arranging the publishing on this kind of directly government funded system is not so easy in legal wise when it comes to direct money making as of selling those CD-ROMs... Also it doesn't too well fit to our main business idea of providing all the WAN network services the Academic and Research community needs. Anyway, we are thinking about it, sometimes. On technical side: We have now circa 16 GB of material in the archive. With 600MB per CD-ROM that would do roughly 30 CD-ROMs. We doubt there would be people willing to buy such a huge set of CD-ROMS of which they most propably will want under 10% in any case. Some questimates: Note disk count actual usage /pub/amiga (1) 3 disks 2.3 /pub/archive (newsgroup(s)) (2) 1 disk 0.95 /pub/crypt (3) 1 disk 0.05 /pub/gnu (4) 1 disk 0.9 /pub/mac (5) 1 disk 0.85 /pub/msdos (and os2+win-nt) (6) 4 disks 3.9 /pub/OS/Linux (7) 2 disks 1.2 /pub/pics (8) 2 disks 1.8 /pub/unix (8) 3 disks 2.6 /pub/X11 (8) 2 disks 1.5 Sums: 8.9 GB 18 disks 14.9 ca. 7 GB not covered here Notes: 1) There are multiple CD-ROMS of Amiga. We have same files online, that most of those contain. 2) There are several sources of usenet newsgroups archived on CD-ROMs. Ask UUNET Technologies, and/or EurOpen/EUnet. 3) /pub/crypt/* et.al. are material that are under US munitions control laws (yes, MILITARY SECRETS!), and thus once sent to US, they must not be sent out without horrendous hazzle of paperwork. That kind of disk must primarily be available from the outside of the US... 4) Free Software Foundation sells also a CD-ROM, buy that, and support the developement of free software! More info: gnu@prep.ai.mit.edu ( See /pub/gnu/GNUinfo/ORDERS* ) 7) There are several more or less commercial Linux CD-ROMs. 8) Of these categories there undoubtly are CD-ROMs available, but sources are unknown. Ask your local shops... 9) The number of files increases continuously, we are going to go well beyond 30GB at least FTPD SOURCES: If you want the sources for this FTP server (derived from the Berkeley freely distributable sources) look into /pub/local/src for "ftpd", "ls", and "tar" programs (BSD-compress, and GNU-Zip are unmodified). REPORTING A BUG: If you observe odd behaviour of this server, which is not of what you believe to be correct, please contact problems@ftp.funet.fi and in the report have attached a session log which shows the wrong functionality. However, check at first what we state about "Restrictions" below! Such log should start from your FTP session startup, and it should contain: - Descriptions about your (computing-) environment relevant with attempted FTP access; - Maker and model of the computer where you ran your FTP session, - TCP/IP software model and maker (quite many system do not come with builtin TCP/IP -- VMS-machines are one such example.) - UNEDITED (verbose, unabridged) session transcript showing EVERYTHING you sent to this system, and what were the responses. Note: Reports about corrupted files belong to archive area keepers; they handle those files; "problems" handles the server subsystem. Note to VMS users with UCX earlier than V2.0: YOUR SYSTEM IS FAULTY From gatekeeper.dec.com -ftp login banner: If you are connecting to gatekeeper from a VMS system running a version of UCX earlier than V2.0, a bug in UCX will prevent the automatic login from working. To get around this, wait for the message that says: %UCX-E-FTP_LOGREJ, Login request rejected and then log in by hand with the "login" command at the "FTP>" prompt. You should also consider upgrading to the latest version of UCX. Bugs/problems relating to ARCHIVED MATERIAL: Select by list under: `Contacts about material in here' Uploads: Select by list under: `Contacts about material in here'. If no suitable one can be found, check also /README.UPLOADER. In outmost despair (ONLY then! postmaster@ftp.funet.fi) Bugs/problems relating to archie: Archie-admin: <archie-admin@archie.funet.fi> Bugs/problems relating to other parts of system software: Problems group: <problems@ftp.funet.fi> ("system software" does not mean anything under /pub/") If you can get /README without trouble, don't contact <problems>, but one of earlier mentioned area administration aliases. WHAT IS `FREELY DISTRIBUTABLE' ? Freely distributable does not mean the same thing as PD (public domain). A big portion of the software available here is not in the public domain, although it is freely distributable. Many are copyrighted by some person or organization, but can be distributed freely; there may be limitations on the manner of distribution and/or the usage of the programs. There may also be certain rules concerning the distribution of modified versions (derivate work) of the programs, like saying that if you redistribute a modified version you must include in the distribution the date and author of the modification. Also on many programs you must include a note crediting the original author of the program if you use his code in your own programs. An example of this is the Free Software Foundation's GNU software. GNU software may be distributed freely, provided that the sources are included, an offer to distribute the sources is included or that a pointer to where the sources can be gotten from is included. On FTP.FUNET.FI, all the GNU source code published is available from the directory pub/gnu. Some GNU binaries are available from other directories as well; although we have tried to include a pointer to the sources and the copyright information in these other directories, too, it might be that we have neglected some. This note is here to point you to the sources in pub/gnu. For further information, the GNU copyright is in the file pub/gnu/COPYING. NON-STANDARD FTP FEATURES: This FTPSERVER has some special features which may help on grabbing files from here: <filename>.<NN> See about file-splitting below <filename>.Z Compress designated file while fetching from this system. (Using BSD compress) <filename>.gz Compress designated file while fetching from this system. (Using GNU-Zip) <dirname>.tar Make a TAR (using GNU tar-1.11.2) of dir. <filename>.tar Make a TAR (- " -) of file. <dirname>.tar.Z Make a compressed tar of dir. <dirname>.tar.gz GNU-Ziped variant of above <filename>.tar.Z Make a compressed tar of file. (Why to tar a single file? To get its date & time information too...) <filename>.tar.gz GNU-Ziped variant of above <filename>+".Z" How to say... There exists file: <filename>.Z, you ask it to be UNCOMPRESSED for FTP transfer... (For all of you who can't uncompress a'la BSD UNIX.) <filename>+".gz" Same as above, but with GNU-UnZip. Note: It isn't very useful to compress .arc, .zoo, .gif, .Z or .gz files. Usually they just expand when compressed :-( (Why? They all use similar compression schemes.) Note2: This ftp server won't perform .tar or .tar.Z transfer (mentioned above) for top level directories. This is to avoid accidental loading of whole archives over the network to your disk. Several gigabytes of .tar isn't very easy to handle. So .tar and/or .tar.Z will only work in some subdirectories. Of course, this restriction doesn't apply on regular files. Note3: Unless you REALLY can't uncompress files, please only then do retrieve files in their uncompressed form! (Leaving out the ".Z"/".z"/".gz" from true file path.) There are workable 16-bit UNcompress programs available for all machines which have at least 640k memory! Consider using GNU-Zip, which can decompress BSD compress (.Z), SysV pack (.z), and gzip (.gz) files. Versions for multiple platforms are available, including UNIX, MSDOS, VMS, ... Files can be split while retrieving them by defining the desired part size: ftp> site partsize 720000 and then GETing a file on which name a decimal order number suffix is added: ftp> get BIGFILE.01 ftp> get BIGFILE.02 ftp> get BIGFILE.03 which for a file of 2000 000 bytes would produce parts: BIGFILE.01 720 000 bytes BIGFILE.02 720 000 bytes BIGFILE.03 560 000 bytes An attempt to get BIGFILE.04 would result an error message about retrieve beyond the end of the file... Special command `SITE FIND globexpr' (your average UNIX ftp client accepts it like this: `quote site find gcc960') to run SH-GLOB- expression matching against the filenames in archive. It scans special file with ordinary" GNU-fastfind -program. Alternate usage method is to GET a pseudo-file with prefix: /search: Those exact 8 chars, not "/SEARCH:" or something else.. This returns the query report in the data-stream, and usually the user must do explicite result renameing; UNIX-style: ftp> get "/search:gcc960" gcc960.search.log If you have a special FTP client, which sends PORT command before sending SITE FIND command, you can get search result into a file. (ftp.funet.fi:/pub/local/src/net2+mea-ftp.tar.gz) PHYSICAL DISK STRUCTURE IS HIDDEN BEHIND LOGICAL ONE: This server tries to hide physical disks and symlinks used to point to them from the anonymous user, but occasionally you can trick it to behave oddly. For example under some conditions some multi-argument ls command (NLST primitive) can create odd listings which are not of what you might have expected. We don't see any REAL need to hide physical structure completely, nor to make even `ls' programs view of it bullet proof, but tell us your opinion. ( -> problems@ftp.funet.fi ) Most of the time "cd .." will move you one step up in your current directory -- even when a component in it a symlink. The way this is implemented is described in /staff-docs/ftpd-ls.README. RESTRICTIONS: This FTPSERVER counts the number of anonymous customers on several classes defined by IP-connection origin. Finns, and NORDUnet-users are not limited (in practice limits are very high and usually don't limit anything.), FOREIGN (from outside Finland/NORDUnet) anonymous users are limited on max 100 users. Each user class is also limited on how much bandwidth they are given, Finland and NORDUnet are infinite (well, no limit, just real-time logging), FOREIGN get some lower values (1280 B/s). (Note: These "current" values are subject to day-to-day management actions, and can be changed without advance notice. These were current values when this part of the document was written.) Note that we are located far away from the USA. Our connection to the USA is a 1024 kbits/sec terrestrial link (which is used by all the scandinavian countries). Our main purpose is to be central repository for finnish users. Lately traffic on that link has been TWICE as great TO the USA as it has been to Finland, think about that... (Our funders ask tough questions about that..) MINIMUM OF MAXIMUM RETRIEVAL RATE: Due to above mentioned resource limits, this server implements a throttle to limit individual users usage of scarce resource: line capacity. Algorithm goes like follows: max_rate = Max_anonymous_logins * minimum_maximum_rate / present_count_of_data_transfers Where: max_rate is in (k)bytes/sec Max_anonymous_logins is count shown at anonymous FTP login (32) (Current value listed to you when you login.) minimum_maximum_rate is rate shown at anonymous FTP login (1kB/s) present_count_of_data_transfers is a figure derived from ftp-server internal mechanism -- It tells (at sample time) how many are really transferring out of those who have logged in under your limited class. If user can't use the share s/he has been allocated, nobody else will get the leftovers (well, that line will be saturated anyway...) This yields a rate which can be anything in between 1kB/s and 32kB/s. (32kB/s is when you are only one transferring at the moment.) IP-REVERSAL AND VALID "PASSWD" REQUIREMENTS: Any system without a valid IP reversal mapping will get a view of directories which is even more restricted than the usual anonymous user. The same is true when the email address you have entered as password does not conform with RFC822 rules. If your IP address does not have IN-ADDR.ARPA. -reverse mapping defined, this is a task for your network administrator. Your NetAdmin must register reversing database into IN-ADDR.ARPA. -domain, and make sure all of your local hosts have IP reversals defined! (This registration is done with HOSTMASTER@Internic.NET, once your local DNS service provides the data.) What we expect of IP reversals is valid top 2 domains: 130.232.7.250 --> non-registered-pc.utu.fi We are NOT interested in truly valid reversals, unless you want to upload something! This reversal is achieved with IP reversal entry in named.reverse: --------- $ ORIGIN 232.130.in-addr.arpa. ; all KNOWN 130.232.7.XX hosts here before "fallback" *.7 IN PTR non-registered-pc.utu.fi. --------- Simple and effective! Talk with your network management, they should know what this is all about. (If they don't, they can ask us.) Passwords for anonymous FTP are expected to be email addresses. They are expected to contain `@'-character in them, and be according to RFC822: Luser.Name@Host.Domain Luser%OtherHost@RelayHost.Domain This address need NOT be on host you are using for FTP, but it must be valid address to you in your preferred system. Valid email addresses are especially important if you want to upload something. On uploads email address validity is enforced by area moderators, who may not want to make uploaded material public, if it isn't traceable. NOTE: If your IP-reversal fails, but you do have a host with globally accessible name->IP-address entry, and that host is in the same network as is the host you are using, then you can get past the restriction by using username@host-in-the-same.net as your password. Special case: Use the name of your host itself, if it has a valid address entry. OTHER AVAILABLE SERVICES (Here or near by) You can make interactive login to archie.funet.fi with userid `archie'. List of current Archies sites: (23 Aug 93): (In a sort of nearness order from our point of view) archie.funet.fi 128.214.6.102 (European server in Finland) archie.luth.se 130.240.18.4 (Sweden) archie.doc.ic.ac.uk 146.169.11.3 (UK/Europe server) archie.th-darmstadt.de 130.83.128.111 (Germany) archie.huji.ac.il 132.65.20.254 (Israel server) archie.rutgers.edu 128.6.18.15 (Rutgers University) archie.unl.edu 129.93.1.14 (University of Nebraska in Lincoln) archie.ans.net 147.225.1.10 (ANS archie server) archie.wide.ad.jp 133.4.3.6 (Japanese server) archie.kuis.kyoto-u.ac.jp 130.54.20.1 (Japan) archie.ncu.edu.tw 140.115.19.24 (Taiwanese server) archie.kr 163.239.1.11 (Korean server) archie.au 139.130.4.6 (Australian server) archie.nz 130.195.9.4 (New Zealand server) Up to date listing is viewed when you login to the archie. There exists a mail-based archie-service, which is actually the preferred form of querying if you (for some odd reason) can't have prospero-based archie-client in our own system: (Or don't have full Internet connectivity.) To: mailserver@ftp.funet.fi Subject: learning about archie utility help archie This system has also another mail responding server: mailserver@ftp.funet.fi (And also mailserver@lists.funet.fi, if you access mailinglists.) In mail body have line: `help'. (Subject line is not used as a command, but is used to build reply message.) To: mailserver@ftp.funet.fi Subject: Charley Curious probing mailserver help help help MANY NAMES OF THE SERVER This server group has many names. Its "staff" will always be at `nic.funet.fi', but otherwise consider using philosophy: `name by function', thus FTP from ftp.funet.fi. We have systems by their services: ARCHIE.FUNET.FI telnet, and login: archie, or use archie-clients. FTP.FUNET.FI Via Anonymous FTP GOPHER.FUNET.FI Via Gopher-clients INFO.FUNET.FI telnet, and login: info Select what service you want to use (www, wais, gopher, ..) IRC.FUNET.FI IRC network server, no direct client access -- use your local server, or ask irc@irc.funet.fi about connecting your local server (Finland only!) LISTSERV.FUNET.FI Mailinglists via LISTSERV@LISTSERV.FUNET.FI LISTS.FUNET.FI Mailinglists via mailserver@lists.funet.fi (Most of LISTS -lists will move to LISTSERV..) NIC.FUNET.FI Original machine, management staff, main mailer, file-delivering mailserver, and X.500 interface logins: dua, fred WAIS.FUNET.FI Several WAIS databases. Use WAIS clients WWW.FUNET.FI World Wide Web-hypermedia server. Use WWW clients Not all of them are on separate machines, but what physical machine runs what service is subject to more or less sudden change if we see it necessary. (And get more hardware..) Therefore always try to use names of services instead of machines... All will be well when you use `name by function' assumption, and have a workable network address lookup mechanism.