Welcome to our conversion of:
   Linux Ethernet-Howto
   by Paul Gortmaker
   v2.8, Oct 29, 2000
  
Contents
   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. 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 like ifconfig and route. See the Network Howto
   for that stuff.
   ______________________________________________________________________
  
   Table of Contents
  
  
  
   1. Introduction
  
   1.1 New Versions of this Document
   1.2 Using the Ethernet-Howto
   1.3 HELP - It doesn't work!
   1.4 Type of cable that your card should support
  
   2. Frequently Asked Questions
  
   2.1 What card should I buy for Linux?
   2.2 Alpha Drivers -- Getting and Using them
   2.3 Using More than one Ethernet Card per Machine
   2.4 The
   2.5 Problems with NE1000 / NE2000 cards (and clones)
   2.6 Problems with SMC Ultra/EtherEZ and WD80*3 cards
   2.7 Problems with 3Com cards
   2.8 FAQs Not Specific to Any Card.
   2.8.1 Linux and ISA Plug and Play Ethernet Cards
   2.8.2 Ethercard is Not Detected at Boot.
   2.8.3 (TT
   2.8.4 PCI machine detects card but driver fails probe.
   2.8.5 Shared Memory ISA cards in PCI Machine do not work (
   2.8.6 Card seems to send data but never receives anything.
   2.8.7 Asynchronous Transfer Mode (ATM) Support
   2.8.8 Gigabyte Ethernet Support
   2.8.9 FDDI Support
   2.8.10 Full Duplex Support
   2.8.11 Ethernet Cards for Linux on SMP Machines
   2.8.12 Ethernet Cards for Linux on Alpha/AXP PCI Boards
   2.8.13 Ethernet for Linux on SUN/Sparc Hardware.
   2.8.14 Ethernet for Linux on Other Hardware.
   2.8.15 Linking 10 or 100 BaseT without a Hub
   2.8.16 SIOCSIFxxx: No such device
   2.8.17 SIOCSFFLAGS: Try again
   2.8.18 Using `ifconfig' and Link UNSPEC with HW-addr of 00:00:00:00:00:00
   2.8.19 Huge Number of RX and TX Errors
   2.8.20 Entries in
   2.8.21 Linux and ``trailers''
   2.8.22 Access to the raw Ethernet Device
  
   3. Performance Tips
  
   3.1 General Concepts
   3.2 ISA Cards and ISA Bus Speed
   3.3 Setting the TCP Rx Window
   3.4 Increasing NFS performance
  
   4. Vendor/Manufacturer/Model Specific Information
  
   4.1 3Com
   4.1.1 3c501
   4.1.2 EtherLink II, 3c503, 3c503/16
   4.1.3 Etherlink Plus 3c505
   4.1.4 Etherlink-16 3c507
   4.1.5 Etherlink III, 3c509 / 3c509B
   4.1.6 3c515
   4.1.7 3c523
   4.1.8 3c527
   4.1.9 3c529
   4.1.10 3c562
   4.1.11 3c575
   4.1.12 3c579
   4.1.13 3c589 / 3c589B
   4.1.14 3c590 / 3c595
   4.1.15 3c592 / 3c597
   4.1.16 3c900 / 3c905 / 3c905B / 3c905C
   4.1.17 3c985
   4.2 Accton
   4.2.1 Accton MPX
   4.2.2 Accton EN1203, EN1207, EtherDuo-PCI
   4.2.3 Accton EN2209 Parallel Port Adaptor (EtherPocket)
   4.2.4 Accton EN2212 PCMCIA Card
   4.3 Allied Telesyn/Telesis
   4.3.1 AT1500
   4.3.2 AT1700
   4.3.3 AT2400
   4.3.4 AT2450
   4.3.5 AT2500
   4.3.6 AT2540FX
   4.4 AMD / Advanced Micro Devices
   4.4.1 AMD LANCE (7990, 79C960/961/961A, PCnet-ISA)
   4.4.2 AMD 79C965 (PCnet-32)
   4.4.3 AMD 79C970/970A (PCnet-PCI)
   4.4.4 AMD 79C971 (PCnet-FAST)
   4.4.5 AMD 79C972 (PCnet-FAST+)
   4.4.6 AMD 79C974 (PCnet-SCSI)
   4.5 Ansel Communications
   4.5.1 AC3200 EISA
   4.6 Apricot
   4.6.1 Apricot Xen-II On Board Ethernet
   4.7 Arcnet
   4.8 AT&T
   4.8.1 AT&T T7231 (LanPACER+)
   4.9 Boca Research
   4.9.1 Boca BEN400
   4.9.2 Boca BEN (ISA, VLB, PCI)
   4.10 Cabletron
   4.10.1 E10**, E10**-x, E20**, E20**-x
   4.10.2 E2100
   4.10.3 E22**
   4.11 Cogent
   4.11.1 EM100-ISA/EISA
   4.11.2 Cogent eMASTER+, EM100-PCI, EM400, EM960, EM964
   4.12 Compaq
   4.12.1 Compaq Deskpro / Compaq XL (Embedded AMD Chip)
   4.12.2 Compaq Nettelligent/NetFlex (Embedded ThunderLAN Chip)
   4.12.3 Compaq PCI card
   4.13 Danpex
   4.13.1 Danpex EN9400
   4.14 D-Link
   4.14.1 DE-100, DE-200, DE-220-T, DE-250
   4.14.2 DE-520
   4.14.3 DE-528
   4.14.4 DE-530
   4.14.5 DE-600
   4.14.6 DE-620
   4.14.7 DE-650
   4.14.8 DFE-530TX
   4.14.9 DFE-538TX
   4.15 DFI
   4.15.1 DFINET-300 and DFINET-400
   4.16 Digital / DEC
   4.16.1 DEPCA, DE100/1, DE200/1/2, DE210, DE422
   4.16.2 Digital EtherWorks 3 (DE203, DE204, DE205)
   4.16.3 DE425 EISA, DE434, DE435, DE500
   4.16.4 DEC 21040, 21041, 2114x, Tulip
   4.17 Farallon
   4.17.1 Farallon Etherwave
   4.17.2 Farallon PCI 593
   4.18 Fujitsu
   4.18.1 Fujitsu FMV-181/182/183/184
   4.19 Hewlett Packard
   4.19.1 HP Night Director+ 10/100
   4.19.2 27245A
   4.19.3 HP EtherTwist, PC Lan+ (27247, 27252A)
   4.19.4 HP-J2405A
   4.19.5 HP-Vectra On Board Ethernet
   4.19.6 HP 10/100 VG Any Lan Cards (27248B, J2573, J2577, J2585, J970, J973)
   4.19.7 HP NetServer 10/100TX PCI (D5013A)
   4.20 IBM / International Business Machines
   4.20.1 IBM Thinkpad 300
   4.20.2 IBM Credit Card Adaptor for Ethernet
   4.20.3 IBM 10/100 EtherJet PCI
   4.20.4 IBM Token Ring
   4.21 ICL Ethernet Cards
   4.21.1 ICL EtherTeam 16i/32
   4.22 Intel Ethernet Cards
   4.22.1 Ether Express
   4.22.2 Ether Express PRO/10 (PRO/10+)
   4.22.3 Ether Express PRO/10 PCI (EISA)
   4.22.4 Ether Express PRO 10/100B
   4.23 Kingston
   4.24 LinkSys
   4.24.1 LinkSys Etherfast 10/100 Cards.
   4.24.2 LinkSys Pocket Ethernet Adapter Plus (PEAEPP)
   4.24.3 LinkSys PCMCIA Adaptor
   4.25 Microdyne (Eagle)
   4.25.1 Microdyne Exos 205T
   4.26 Mylex
   4.26.1 Mylex LNE390A, LNE390B
   4.26.2 Mylex LNP101
   4.26.3 Mylex LNP104
   4.27 Novell Ethernet, NExxxx and associated clones.
   4.27.1 NE1000, NE2000
   4.27.2 NE2000-PCI (RealTek/Winbond/Compex)
   4.27.3 NE-10/100
   4.27.4 NE1500, NE2100
   4.27.5 NE/2 MCA
   4.27.6 NE3200
   4.27.7 NE3210
   4.27.8 NE5500
   4.28 Proteon
   4.28.1 Proteon P1370-EA
   4.28.2 Proteon P1670-EA
   4.29 Pure Data
   4.29.1 PDUC8028, PDI8023
   4.30 Racal-Interlan
   4.30.1 ES3210
   4.30.2 NI5010
   4.30.3 NI5210
   4.30.4 NI6510 (not EB)
   4.30.5 EtherBlaster (aka NI6510EB)
   4.31 RealTek
   4.31.1 RealTek RTL8002/8012 (AT-Lan-Tec) Pocket adaptor
   4.31.2 RealTek 8009
   4.31.3 RealTek 8019
   4.31.4 RealTek 8029
   4.31.5 RealTek 8129/8139
   4.32 Sager
   4.32.1 Sager NP943
   4.33 Schneider & Koch
   4.33.1 SK G16
   4.34 SEEQ
   4.34.1 SEEQ 8005
   4.35 SMC (Standard Microsystems Corp.)
   4.35.1 WD8003, SMC Elite
   4.35.2 WD8013, SMC Elite16
   4.35.3 SMC Elite Ultra
   4.35.4 SMC Elite Ultra32 EISA
   4.35.5 SMC EtherEZ (8416)
   4.35.6 SMC EtherPower PCI (8432)
   4.35.7 SMC EtherPower II PCI (9432)
   4.35.8 SMC 1211TX 10/100
   4.35.9 SMC 3008
   4.35.10 SMC 3016
   4.35.11 SMC-9000 / SMC 91c92/4
   4.35.12 SMC 91c100
   4.36 Texas Instruments
   4.36.1 ThunderLAN
   4.37 Thomas Conrad
   4.37.1 Thomas Conrad TC-5048
   4.38 VIA
   4.38.1 VIA 86C926 Amazon
   4.38.2 VIA 86C100A Rhine II (and 3043 Rhine I)
   4.39 Western Digital
   4.40 Winbond
   4.40.1 Winbond 89c840
   4.40.2 Winbond 89c904, 89c905, 89c906
   4.40.3 Winbond 89c940
   4.41 Xircom
   4.41.1 Xircom PE1, PE2, PE3-10B*
   4.41.2 Xircom PCMCIA Cards
   4.42 Zenith
   4.42.1 Z-Note
   4.43 Znyx
   4.43.1 Znyx ZX342 (DEC 21040 based)
   4.44 Identifying an Unknown Card
   4.44.1 Identifying the Network Interface Controller
   4.44.2 Identifying the Ethernet Address
   4.44.3 Identifying the Card by the FCC ID Number
   4.44.4 Tips on Trying to Use an Unknown Card
   4.45 Drivers for Non-Ethernet Devices
  
   5. Cables, Coax, Twisted Pair
  
   5.1 Thin Ethernet (thinnet)
   5.2 Twisted Pair
   5.3 Thick Ethernet
  
   6. Software Configuration and Card Diagnostics
  
   6.1 Configuration Programs for Ethernet Cards
   6.1.1 WD80x3 Cards
   6.1.2 Digital / DEC Cards
   6.1.3 NE2000+ or AT/LANTIC Cards
   6.1.4 3Com Cards
   6.2 Diagnostic Programs for Ethernet Cards
  
   7. Technical Information
  
   7.1 Programmed I/O vs. Shared Memory vs. DMA
   7.1.1 Programmed I/O (e.g. NE2000, 3c509)
   7.1.2 Shared memory (e.g. WD80x3, SMC-Ultra, 3c503)
   7.1.3 Slave (normal) Direct Memory Access (e.g. none for Linux!)
   7.1.4 Bus Master Direct Memory Access (e.g. LANCE, DEC 21040)
   7.2 Performance Implications of Bus Width
   7.2.1 ISA Eight bit vs ISA 16 bit Cards
   7.3 32 Bit (VLB/EISA/PCI) Ethernet Cards
   7.4 Writing a Driver
   7.5 Driver interface to the kernel
   7.5.1 Probe
   7.5.2 Interrupt handler
   7.5.3 Transmit function
   7.5.4 Receive function
   7.5.5 Open function
   7.5.6 Close function (optional)
   7.5.7 Miscellaneous functions
   7.6 Technical information from 3Com
   7.7 Notes on AMD PCnet / LANCE Based cards
   7.8 Multicast and Promiscuous Mode
   7.9 The Berkeley Packet Filter (BPF)
  
   8. Networking with a Laptop/Notebook Computer
  
   8.1 Using SLIP
   8.2 PCMCIA Support
   8.3 ISA Ethercard in the Docking Station.
   8.4 Pocket / parallel port adaptors.
  
   9. Miscellaneous.
  
   9.1 Passing Ethernet Arguments to the Kernel
   9.1.1 The
   9.1.2 The
   9.2 Using the Ethernet Drivers as Modules
   9.3 Related Documentation
   9.4 Disclaimer and Copyright
   9.5 Closing
  
  
   ______________________________________________________________________
  
   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-3 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 rtfm.mit.edu
   just like all the other newsgroup FAQs.
  
   This present revision covers distribution kernels up to and including
   2.2.17.
  
   The Ethernet-Howto is by:
  
   Paul Gortmaker, p_gortmaker@yahoo.com
  
  
   The primary source of information for the initial ASCII-only version
   of the Ethernet-Howto was:
  
   Donald J. Becker, becker@scyld.com
  
  
   who we should thank for writing a lot of the ethernet card drivers
   that are presently available for Linux. He also is the author of the
   original NFS server too. Thanks Donald!
  
   This document is Copyright (c) 1993-2000 by Paul Gortmaker. Please
   see the Disclaimer and Copying information at the end of this document
   (``copyright'') for information about redistribution of this document
   and the usual `we are not responsible for what you manage to break...'
   type legal stuff.
   1.1. New Versions of this Document
  
  
   New versions of this document can be retrieved from:
  
   Ethernet-HOWTO <http://metalab.unc.edu/mdw/HOWTO/Ethernet-HOWTO.html>
  
   or for those wishing to use FTP and/or get non-HTML formats:
  
   Sunsite HOWTO Archive <ftp://metalab.unc.edu/pub/Linux/docs/HOWTO/>
  
   This is the `official' location - it can also be found on various
   Linux WWW/ftp mirror sites. Updates will be made as new information
   and/or drivers becomes available. If this copy that you are reading is
   more than 6 months old, then you should check to see if an updated
   copy is available.
  
   This document is available in various formats (postscript, dvi, ASCII,
   HTML, etc.). I would recommend viewing it in HTML (via a WWW browser)
   or the Postscript/dvi format. Both of these contain cross-references
   that are not included in the plain text ASCII format.
  
  
  
   1.2. 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 the good
   news is that you don't have to read it all. The HTML and
   Postscript/dvi versions have a table of contents which will really
   help you find what you need a lot faster.
  
   Chances are you are reading this document beacuse you can't get things
   to work and you don't know what to do or check. The next section
   (``HELP - It doesn't work!'') is aimed at newcomers to linux and will
   point you in the right direction.
  
   Typically the same problems and questions are asked over and over
   again by different people. Chances are your specific problem or
   question is one of these Frequently Asked Questions, and is answered
   in the FAQ portion of this document . (``The FAQ section'').
   Everybody should have a look through this section before posting for
   help.
  
   If you haven't got an ethernet card, then you will want to start with
   deciding on a card. (``What card should I buy...'')
  
   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 the section which
   contains specific information on each manufacturer, and their cards.
   (``Vendor Specific...'')
  
   If you are interested in some of the technical aspects of the Linux
   device drivers, then you can have a browse of the section with this
   type of information. (``Technical Information'')
  
  
   1.3. HELP - It doesn't work!
  
  
   Okay, don't panic. This will lead you through the process of getting
   things working, even if you have no prior background in linux or
   ethernet hardware.
  
  
   First thing you need to do is figure out what model your card is so
   you can determine if Linux has a driver for that particular card.
   Different cards typically have different ways of being controlled by
   the host computer, and the linux driver (if there is one) contains
   this control information in a format that allows linux to use the
   card. If you don't have any manuals or anything of the sort that tell
   you anything about the card model, then you can try the section on
   helping with mystery cards (reference section: ``Identifying an
   Unknown Card'').
  
   Now that you know what type of card you have, read through the details
   of your particular card in the card specific section (reference
   section: ``Vendor Specific...'') which lists in alphabetical order,
   card manufacturers, individual model numbers and whether it has a
   linux driver or not. If it lists it as `Not Supported' you can pretty
   much give up here. If you can't find your card in that list, then
   check to see if your card manual lists it as being `compatible' with
   another known card type. For example there are hundreds, if not
   thousands of different cards made to be compatible with the original
   Novell NE2000 design.
  
   Assuming you have found out that a linux driver exists for your card,
   you now have to find it and make use of it. Just because linux has a
   driver for your card does not mean that it is built into every kernel.
   (The kernel is the core operating system that is first loaded at boot,
   and contains drivers for various pieces of hardware, among other
   things.) Depending on who made the particular linux distribution you
   are using, there may be only a few pre-built kernels, and a whole
   bunch of drivers as smaller separate modules, or there may be a whole
   lot of kernels, covering a vast combination of built-in driver
   combinations.
  
   Most linux distributions now ship with a bunch of small modules that
   are the various drivers. The required modules are typically loaded
   late in the boot process, or on-demand as a driver is needed to access
   a particualr device. You will need to attach this module to the
   kernel after it has booted up. See the information that came with your
   distribution on installing and using modules, along with the module
   section in this document. (``Using the Ethernet Drivers as Modules'')
  
   If you didn't find either a pre-built kernel with your driver, or a
   module form of the driver, chances are you have a typically uncommon
   card, and you will have to build your own kernel with that driver
   included. Once you have linux installed, building a custom kernel is
   not difficult at all. You essentially answer yes or no to what you
   want the kernel to contain, and then tell it to build it. There is a
   Kernel-HowTo that will help you along.
  
   At this point you should have somehow managed to be booting a kernel
   with your driver built in, or be loading it as a module. About half
   of the problems people have are related to not having driver loaded
   one way or another, so you may find things work now.
  
   If it still doesn't work, then you need to verify that the kernel is
   indeed detecting the card. To do this, you need to type dmesg | more
   when logged in after the system has booted and all modules have been
   loaded. This will allow you to review the boot messages that the
   kernel scrolled up the screen during the boot process. If the card
   has been detected, you should see somewhere in that list a message
   from your card's driver that starts with eth0, mentions the driver
   name and the hardware parameters (interrupt setting, input/output port
   address, etc) that the card is set for. (Note: At boot, linux lists
   all the PCI cards installed in the system, regardless of what drivers
   are available - do not mistake this for the driver detection which
   comes later!)
  
   If you don't see a driver indentification message like this, then the
   driver didn't detect your card, and that is why things aren't working.
   See the FAQ (``The FAQ Section'') for what to do if your card is not
   detected. If you have a NE2000 compatible, there is also some NE2000
   specific tips on getting a card detected in the FAQ section as well.
  
   If the card is detected, but the detection message reports some sort
   of error, like a resource conflict, then the driver probably won't
   have initialized properly and the card still wont be useable. Most
   common error messages of this sort are also listed in the FAQ section,
   along with a solution.
  
   If the detection message seems okay, then double check the card
   resources reported by the driver against those that the card is
   physically set for (either by little black jumpers on the card, or by
   a software utility supplied by the card manufacturer.) These must
   match exactly. For example, if you have the card jumpered or
   configured to IRQ 15 and the driver reports IRQ 10 in the boot
   messages, things will not work. The FAQ section discusses the most
   common cases of drivers incorrectly detecting the configuration
   information of various cards.
  
   At this point, you have managed to get you card detected with all the
   correct parameters, and hopefully everything is working. If not, then
   you either have a software configuration error, or a hardware
   configuration error. A software configuration error is not setting up
   the right network addresses for the ifconfig and route commands, and
   details of how to do that are fully described in the Network HowTo and
   the `Network Administrator's Guide' which both probably came on the
   CD-ROM you installed from.
  
   A hardware configuration error is when some sort of resource conflict
   or mis-configuration (that the driver didn't detect at boot) stops the
   card from working properly. This typically can be observed in several
   different ways. (1) You get an error message when ifconfig tries to
   open the device for use, such as ``SIOCSFFLAGS: Try again''. (2) The
   driver reports eth0 error messages (viewed by dmesg | more) or strange
   inconsistencies for each time it tries to send or receive data. (3)
   Typing cat /proc/net/dev shows non-zero numbers in one of the errs,
   drop, fifo, frame or carrier columns for eth0. (4) Typing cat
   /proc/interrupts shows a zero interrupt count for the card. Most of
   the typical hardware configuration errors are also discussed in the
   FAQ section.
  
   Well, if you have got to this point and things still aren't working,
   read the FAQ section of this document, read the vendor specific
   section detailing your particular card, and if it still doesn't work
   then you may have to resort to posting to an appropriate newsgroup for
   help. If you do post, please detail all relevant information in that
   post, such as the card brand, the kernel version, the driver boot
   messages, the output from cat /proc/net/dev, a clear description of
   the problem, and of course what you have already tried to do in an
   effort to get things to work.
  
   You would be surprised at how many people post useless things like
   ``Can someone help me? My ethernet doesn't work.'' and nothing else.
   Readers of the newsgroups tend to ignore such silly posts, whereas a
   detailed and informational problem description may allow a `linux-
   guru' to spot your problem right away. Of course the same holds true
   when e-mailing a problem report - always provide as much information
   as possible.
  
  
  
   1.4. Type of cable that your card should support
  
  
   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. The 15 pin D-shaped plug found
   on some ethernet cards (the AUI connector) is used to connect to thick
   ethernet and external transcievers.
  
   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.
  
   Most installations will use 10BaseT/100BaseT 10Base2 does not offer
   any upgrade path to 100Base-whatever. 10Base2 is fine for hobbyists
   setting up a home network when purchasing a hub is not desireable for
   some reason or another.
  
   See ``Cables, Coax...'' for other concerns with different types of
   ethernet cable.
  
  
   2. 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'. Chances are the question you
   want an answer for has already been asked (and answered!) by someone
   else, so even if you don't find your answer here, you probably can
   find what you want from a news archive such as Dejanews
   <http://www.dejanews.com>.
  
  
  
   2.1. What card should I buy for Linux?
  
  
   The answer to this question depends heavily on exactly what you intend
   on doing with your net connection, and how much traffic it will see.
  
   If you only expect a single user to be doing the occasional ftp
   session or WWW connection, then even an old 8 bit ISA card will
   probably keep you happy.
  
   If you intend to set up a server, and you require the CPU overhead of
   moving data over the network to be kept to a minimum, you probably
   want to look at one of the PCI cards that uses a chip with bus-
   mastering capapbility, such as the DEC tulip (21xxx) chip, or the AMD
   PCnet-PCI chip.
  
   If you fall somewhere in the middle of the above, then any one of the
   low cost PCI or 16 bit ISA cards with stable drivers will do the job
   for you.
  
  
  
   2.2. Alpha Drivers -- Getting and Using them
  
  
   I heard that there is an updated or preliminary/alpha driver available
   for my card. Where can I get it?
  
   The newest of the `new' drivers can be found on Donald's ftp site:
   www.scyld.com in the /pub/linux/ area. Things change here quite
   frequently, so just look around for it. Alternatively, it may be
   easier to use a WWW browser on:
  
   Don's Linux Home Page <http://www.scyld.com/linux/>
  
   to locate the driver that you are looking for. (Watch out for WWW
   browsers that silently munge the source by replacing TABs with spaces
   and so on - use ftp, or at least an FTP URL for downloading if
   unsure.)
  
   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!
  
   Note that some of the `useable' experimental/alpha drivers have been
   included in the standard kernel source tree. When running make config
   one of the first things you will be asked is whether to ``Prompt for
   development and/or incomplete code/drivers''. You will have to answer
   `Y' here to get asked about including any alpha/experiemntal drivers.
  
  
   2.3. Using More than one Ethernet Card per Machine
  
  
   What needs to be done so that Linux can run two ethernet cards?
  
   The answer to this question depends on whether the driver(s) is/are
   being used as a loadable module or are compiled directly into the
   kernel. Most linux distributions use modular drivers now. This saves
   distributing lots of kernels, each with a different driver set built
   in. Instead a single basic kernel is used and the individual drivers
   that are need for a particular user's system are loaded once the
   system has booted far enough to access the driver module files
   (usually stored in /lib/modules/).
  
   With the Driver as a Module: In the case of PCI drivers, the module
   will typically detect all of the installed cards of that brand model
   automatically. However, for ISA cards, probing for a card is not a
   safe operation, and hence you typically need to supply the I/O base
   address of the card so the module knows where to look. This
   information is stored in the file /etc/conf.modules.
  
   As an example, consider a user that has two ISA NE2000 cards, one at
   0x300 and one at 0x240 and what lines they would have in their
   /etc/conf.modules file:
  
  
   alias eth0 ne
   alias eth1 ne
   options ne io=0x240,0x300
  
  
  
   What this does: This says that if the administrator (or the kernel)
   does a modprobe eth0 or a modprobe eth1 then the ne.o driver should be
   loaded for either eth0 or eth1. Furthermore, when the ne.o module is
   loaded, it should be loaded with the options io=0x240,0x300 so that
   the driver knows where to look for the cards. Note that the 0x is
   important - things like 300h as commonly used in the DOS world won't
   work. Switching the order of the 0x240 and the 0x300 will switch
   which physical card ends up as eth0 and eth1.
  
   Most of the ISA module drivers can take multiple comma separated I/O
   values like this example to handle multiple cards. However, some
   (older?) drivers, such as the 3c501.o module are currently only able
   to handle one card per module load. In this case you can load the
   module twice to get both cards detected. The /etc/conf.modules file in
   this case would look like:
  
  
   alias eth0 3c501
   alias eth1 3c501
   options eth0 -o 3c501-0 io=0x280 irq=5
   options eth1 -o 3c501-1 io=0x300 irq=7
  
  
  
   In this example the -o option has been used to give each instance of
   the module a unique name, since you can't have two modules loaded with
   the same name. The irq= option has also been used to to specify the
   hardware IRQ setting of the card. (This method can also be used with
   modules that accept comma separated I/O values, but it is less
   efficient since the module ends up being loaded twice when it doesn't
   really need to be.)
  
   As a final example, consider a user with one 3c503 card at 0x350 and
   one SMC Elite16 (wd8013) card at 0x280. They would have:
  
  
   alias eth0 wd
   alias eth1 3c503
   options wd io=0x280
   options 3c503 io=0x350
  
  
  
   For PCI cards, you typically only need the alias lines to correlate
   the ethN interfaces with the appropriate driver name, since the I/O
   base of a PCI card can be safely detected.
  
   The available modules are typically stored in /lib/modules/`uname
   -r`/net where the uname -r command gives the kernel version (e.g.
   2.0.34). You can look in there to see which one matches your card.
   Once you have the correct settings in your conf.modules file, you can
   test things out with:
  
  
   modprobe ethN
   dmesg | tail
  
  
  
   where `N' is the number of the ethernet interface you are testing.
  
  
   With the Driver Compiled into the Kernel: If you have the driver
   compiled into the kernel, then the hooks for multiple ethercards are
   all there. However, note that at the moment only one ethercard is
   auto-probed for by default. This helps to avoid possible boot time
   hangs caused by probing sensitive cards.
  
   (Note: As of late 2.1.x kernels, the boot probes have been sorted into
   safe and unsafe, so that all safe (e.g. PCI and EISA) probes will find
   all related cards automatically. Systems with more than one ethernet
   card with at least one of them being an ISA card will still need to do
   one of the following.)
  
   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.
  
  
   2.4. The ether= thing didn't do anything for me. Why?
  
  
   As described above, the ether= command only works for drivers that are
   compiled into the kernel. Now most distributions use the drivers in a
   modular form, and so the ether= command is rarely used anymore. (Some
   older documentation has yet to be updated to reflect this change.) If
   you want to apply options for a modular ethernet driver you must make
   changes to the /etc/conf.modules file.
  
   If you are using a compiled in driver, and have added an ether= to
   your LILO configuration file, note that it won't take effect until you
   re-run lilo to process the updated configuration file.
  
  
  
   2.5. Problems with NE1000 / NE2000 cards (and clones)
  
  
   Problem: PCI NE2000 clone card is not detected at boot with v2.0.x.
  
   Reason: The ne.c driver up to v2.0.30 only knows about the PCI ID
   number of RealTek 8029 based clone cards. Since then, several others
   have also released PCI NE2000 clone cards, with different PCI ID
   numbers, and hence the driver doesn't detect them.
  
   Solution: The easiest solution is to upgrade to a v2.0.31 (or newer)
   version of the linux kernel. It knows the ID numbers of about five
   different NE2000-PCI chips, and will detect them automatically at boot
   or at module loading time. If you upgrade to 2.0.34 (or newer) there
   is a PCI-only specific NE2000 driver that is slightly smaller and more
   efficient than the original ISA/PCI driver.
  
   Problem: PCI NE2000 clone card is reported as an ne1000 (8 bit card!)
   at boot or when I load the ne.o module for v2.0.x, and hence doesn't
   work.
  
   Reason: Some PCI clones don't implement byte wide access (and hence
   are not truly 100% NE2000 compatible). This causes the probe to think
   they are NE1000 cards.
  
   Solution: You need to upgrade to v2.0.31 (or newer) as described
   above. The driver(s) now check for this hardware bug.
  
   Problem: PCI NE2000 card gets terrible performance, even when reducing
   the window size as described in the Performance Tips section.
  
   Reason: The spec sheets for the original 8390 chip, desgined and sold
   over ten years ago, noted that a dummy read from the chip was required
   before each write operation for maximum reliablity. The driver has
   the facility to do this but it has been disabled by default since the
   v1.2 kernel days. One user has reported that re-enabling this `mis-
   feature' helped their performance with a cheap PCI NE2000 clone card.
  
   Solution: Since it has only been reported as a solution by one person,
   don't get your hopes up. Re-enabling the read before write fix is done
   by simply editing the driver file in linux/drivers/net/, uncommenting
   the line containing NE_RW_BUGFIX and then rebuilding the kernel or
   module as appropriate. Please send an e-mail describing the
   performance difference and type of card/chip you have if this helps
   you. (The same can be done for the ne2k-pci.c driver as well).
  
   Problem: The ne2k-pci.c driver reports error messages like timeout
   waiting for Tx RDC with a PCI NE2000 card and doesn't work right.
  
   Reason: Your card and/or the card to PCI bus link can't handle the
   long word I/O optimization used in this driver.
  
   Solution: Firstly, check the settings available in the BIOS/CMOS setup
   to see if any related to PCI bus timing are too aggressive for
   reliable operation. Otherwise using the ISA/PCI ne.c driver (or
   removing the #define USE_LONGIO from ne2k-pci.c) should let you use
   the card.
  
   Probem: ISA Plug and Play NE2000 (such as RealTek 8019) is not
   detected.
  
   Reason: The original NE2000 specification (and hence the linux NE2000
   driver) does not have support for Plug and Play.
  
   Solution: Use the DOS configuration disk that came with the card to
   disable PnP, and to set the card to a specified I/O address and IRQ.
   Add a line to /etc/conf.modules like options ne io=0xNNN where 0xNNN
   is the hex I/O address you set the card to. (This assumes you are
   using a modular driver; if not then use an ether=0,0xNNN,eth0 argument
   at boot). You may also have to enter the BIOS/CMOS setup and mark the
   IRQ as Legacy-ISA instead of PnP. Alternatively, if you need to leave
   PnP enabled for compatibility with some other operating system, then
   look into the isapnptools package. Try man isapnp to see if it is
   already installed on your system. If not, then have a look at the
   following URL:
  
   ISA PNP Tools <http://www.roestock.demon.co.uk/isapnptools/>
  
  
   Problem: NE*000 driver reports `not found (no reset ack)' during boot
   probe.
  
  
   Reason: This is related to the above change. After the initial
   verification that an 8390 is at the probed I/O address, the reset is
   performed. When the card has completed the reset, it is supposed to
   acknowedge that the reset has completed. Your card doesn't, and so
   the driver assumes that no NE card is present.
  
   Solution: You can tell the driver that you have a bad card by using an
   otherwise unused mem_end hexidecimal value of 0xbad at boot time. You
   have to also supply a non-zero I/O base for the card when using the
   0xbad override. For example, a card that is at 0x340 that doesn't ack
   the reset would use something like:
  
  
   LILO: linux ether=0,0x340,0,0xbad,eth0
  
  
  
   This will allow the card detection to continue, even if your card
   doesn't ACK the reset. If you are using the driver as a module, then
   you can supply the option bad=0xbad just like you supply the I/O
   address.
  
   Problem: NE*000 card hangs machine at first network access.
  
   Reason: This problem has been reported for kernels as old as 1.1.57 to
   the present. It appears confined to a few software configurable clone
   cards. It appears that they expect to be initialized in some special
   way.
  
   Solution: Several people have reported that running the supplied DOS
   software config program and/or the supplied DOS driver prior to warm
   booting (i.e. loadlin or the `three-finger-salute') into linux allowed
   the card to work. This would indicate that these cards need to be
   initialized in a particular fashion, slightly different than what the
   present Linux driver does.
  
   Problem: NE*000 ethercard at 0x360 doesn't get detected.
  
   Reason: 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: There are two ways to get around this. The easiest is to use
   an 0xbad mem_end value as described above for the `no reset ack'
   problem. This will bypass the signature check, as long as a non-zero
   I/O base is also given. This way no recompilation of the kernel is
   required.
  
   The second method (for hackers) involves changing the driver itself,
   and then recompiling your kernel (or module). 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.
  
   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 something like 0x340.
   Alternatively, you can use the ``reserve='' boot argument in
   conjunction with the ``ether='' argument to protect the card from
   other device driver probes.
  
   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. 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 reserve/ether boot arguments.
  
   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: NE2000 not detected at boot - no boot messages at all
  
   Solution: There is no `magic solution' as there can be a number of
   reasons why it wasn't detected. The following list should help you
   walk through the possible problems.
  
   1) Build a new kernel with only the device drivers that you need.
   Verify that you are indeed booting the fresh kernel. Forgetting to run
   lilo, etc. can result in booting the old one. (Look closely at the
   build time/date reported at boot.) Sounds obvious, but we have all
   done it before. Make sure the driver is in fact included in the new
   kernel, by checking the System.map file for names like ne_probe.
  
   2) Look at the boot messages carefully. Does it ever even mention
   doing a ne2k probe such as `NE*000 probe at 0xNNN: not found (blah
   blah)' or does it just fail silently. There is a big difference. Use
   dmesg|more to review the boot messages after logging in, or hit Shift-
   PgUp to scroll the screen up after the boot has completed and the
   login prompt appears.
  
   3) After booting, do a cat /proc/ioports and verify that the full
   iospace that the card will require is vacant. If you are at 0x300 then
   the ne2k driver will ask for 0x300-0x31f. If any other device driver
   has registered even one port anywhere in that range, the probe will
   not take place at that address and will silently continue to the next
   of the probed addresses. A common case is having the lp driver reserve
   0x378 or the second IDE channel reserve 0x376 which stops the ne
   driver from probing 0x360-0x380.
  
   4) Same as above for cat /proc/interrupts. Make sure no other device
   has registered the interrupt that you set the ethercard for. In this
   case, the probe will happen, and the ether driver will complain loudly
   at boot about not being able to get the desired IRQ line.
   5) If you are still stumped by the silent failure of the driver, then
   edit it and add some printk() to the probe. For example, with the ne2k
   you could add/remove lines (marked with a `+' or `-') in
   linux/drivers/net/ne.c like:
  
  
   ______________________________________________________________________
   int reg0 = inb_p(ioaddr);
  
   + printk("NE2k probe - now checking %x\n",ioaddr);
   - if (reg0 == 0xFF)
   + if (reg0 == 0xFF) {
   + printk("NE2k probe - got 0xFF (vacant I/O port)\n");
   return ENODEV;
   + }
   ______________________________________________________________________
  
  
  
   Then it will output messages for each port address that it checks, and
   you will see if your card's address is being probed or not.
  
   6) You can also get the ne2k diagnostic from Don's ftp site (mentioned
   in the howto as well) and see if it is able to detect your card after
   you have booted into linux. Use the `-p 0xNNN' option to tell it where
   to look for the card. (The default is 0x300 and it doesn't go looking
   elsewhere, unlike the boot-time probe.) The output from when it finds
   a card will look something like:
  
  
   ______________________________________________________________________
   Checking the ethercard at 0x300.
   Register 0x0d (0x30d) is 00
   Passed initial NE2000 probe, value 00.
   8390 registers: 0a 00 00 00 63 00 00 00 01 00 30 01 00 00 00 00
   SA PROM 0: 00 00 00 00 c0 c0 b0 b0 05 05 65 65 05 05 20 20
   SA PROM 0x10: 00 00 07 07 0d 0d 01 01 14 14 02 02 57 57 57 57
  
   NE2000 found at 0x300, using start page 0x40 and end page 0x80.
   ______________________________________________________________________
  
  
  
   Your register values and PROM values will probably be different. Note
   that all the PROM values are doubled for a 16 bit card, and that the
   ethernet address (00:00:c0:b0:05:65) appears in the first row, and the
   double 0x57 signature appears at the end of the PROM.
  
   The output from when there is no card installed at 0x300 will look
   something like this:
  
  
   ______________________________________________________________________
   Checking the ethercard at 0x300.
   Register 0x0d (0x30d) is ff
   Failed initial NE2000 probe, value ff.
   8390 registers: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
   SA PROM 0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
   SA PROM 0x10: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
  
   Invalid signature found, wordlength 2.
   ______________________________________________________________________
  
  
  
   The 0xff values arise because that is the value that is returned when
   one reads a vacant I/O port. If you happen to have some other hardware
   in the region that is probed, you may see some non 0xff values as
   well.
  
   7) Try warm booting into linux from a DOS boot floppy (via loadlin)
   after running the supplied DOS driver or config program. It may be
   doing some extra (i.e. non-standard) "magic" to initialize the card.
  
   8) Try Russ Nelson's ne2000.com packet driver to see if even it can
   see your card -- if not, then things do not look good. Example:
  
  
   A:> ne2000 0x60 10 0x300
  
  
   The arguments are software interrupt vector, hardware IRQ, and I/O
   base. You can get it from any msdos archive in pktdrv11.zip -- The
   current version may be newer than 11.
  
  
  
   2.6. Problems with SMC Ultra/EtherEZ and WD80*3 cards
  
  
   Problem: You get messages such as the following:
  
  
   eth0: bogus packet size: 65531, status=0xff, nxpg=0xff
  
  
  
   Reason: There is a shared memory problem.
  
   Solution: The most common reason for this is PCI machines that are not
   configured to map in ISA memory devices. Hence you end up reading the
   PC's RAM (all 0xff values) instead of the RAM on the card that
   contains the data from the received packet.
  
   Other typical problems that are easy to fix are board conflicts,
   having cache or `shadow ROM' enabled for that region, or running your
   ISA 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.
  
   Problem: SMC EtherEZ doesn't work in non-shared memory (PIO) mode.
  
   Reason: Older versions of the Ultra driver only supported the card in
   the shared memory mode of operation.
  
   Solution: The driver in kernel version 2.0 and above also supports the
   programmed I/O mode of operation. Upgrade to v2.0 or newer.
  
   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 in your module configuration file
   (or via a boot time argument for in-kernel drivers).
   Problem: SMC Ultra card is detected as wd8013, but the IRQ and shared
   memory base is wrong.
  
   Reason: The Ultra card looks a lot like a wd8013, and if the Ultra
   driver is not present in the kernel, the wd driver may mistake the
   ultra as a wd8013. The ultra probe comes before the wd probe, so this
   usually shouldn't happen. The ultra stores the IRQ and mem base in the
   EEPROM differently than a wd8013, hence the bogus values reported.
  
   Solution: Recompile with only the drivers you need in the kernel. If
   you have a mix of wd and ultra cards in one machine, and are using
   modules, then load the ultra module first.
  
  
   2.7. 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. The
   driver chooses when the card is ifconfig'ed into operation.
  
   If you are using a modular driver, you can use module parameters to
   set various things, including the IRQ value.
  
   The following selects IRQ9, base location 0x300, <ignored value>, and
   if_port #1 (the external transceiver).
  
  
  
   io=0x300 irq=9 xcvr=1
  
  
   Alternately, if the driver is compiled into the kernel, you can set
   the same values at boot by passing parameters via LILO.
  
  
   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 X invalid, will use autoIRQ.
  
   Reason: The 3c503 card can only use one of IRQ{5, 2/9, 3, 4} (These
   are the only lines that are connected to the card.) If you pass in an
   IRQ value that is not in the above set, you will get the above
   message. Usually, specifying an interrupt value for the 3c503 is not
   necessary. The 3c503 will autoIRQ when it gets ifconfig'ed, and pick
   one of IRQ{5, 2/9, 3, 4}.
  
   Solution: Use one of the valid IRQs listed above, or enable autoIRQ by
   not specifying the IRQ line at all.
  
   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 for in-
   kernel drivers, and at module insertion for modular drivers. 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 for in-kernel drivers.
  
   To specify the AUI port when loading as a module, just append xcvr=1
   to the module options line along with your I/O and IRQ values.
  
  
  
   2.8. FAQs Not Specific to Any Card.
  
  
  
   2.8.1. Linux and ISA Plug and Play Ethernet Cards
  
  
   For best results (and minimum aggravation) it is recommended that you
   use the (usually DOS) program that came with your card to disable the
   PnP mechanism and set it to a fixed I/O address and IRQ. Make sure
   the I/O address you use is probed by the driver at boot, or if using
   modules then supply the address as an io= option in /etc/conf.modules.
   You may also have to enter the BIOS/CMOS setup and mark the IRQ as
   Legacy-ISA instead of PnP (if your computer has this option).
  
   Note that you typically don't need DOS installed to run a DOS based
   configuration program. You can usually just boot a DOS floppy disk and
   run them from the supplied floppy disk. You can also download OpenDOS
   and FreeDOS for free.
  
   If you require PnP enabled for compatibility with some other operating
   system then you will have to use the isapnptools package with linux to
   configure the card(s) each time at boot. You will still have to make
   sure the I/O address chosen for the card is probed by the driver or
   supplied as an io= option.
  
   Some systems have an `enable PnP OS' (or similar named) option in the
   BIOS/CMOS setup menu which will need to be disabled in nearly all
   cases or the cards won't work properly, or even be detected . Best
   described by one user who said `I don't know what it does behind the
   scenes, but it seems to be evil.'
  
  
   2.8.2. Ethercard is Not Detected at Boot.
  
  
   The usual reason for this is that people are using a kernel that does
   not have support for their particular card built in. For a modular
   kernel, it usually means that the required module has not been
   requested for loading, or that an I/O address needs to be specified as
   a module option.
  
   If you are using a modular based kernel, such as those installed by
   most of the linux distributions, then try and use the configuration
   utility for the distribution to select the module for your card. For
   ISA cards, it is a good idea to determine the I/O address of the card
   and add it as an option (e.g. io=0x340) if the configuration utility
   asks for any options. If there is no configuration utility, then you
   will have to add the correct module name (and options) to
   /etc/conf.modules -- see man modprobe for more details.
  
  
   If you are using a pre-compiled kernel that is part of a distribution
   set, then check the documentation to see which kernel you installed,
   and if it was built with support for your particular card. If it
   wasn't, then your options are to try and get one that has support for
   your card, or build your own.
  
   It is usually wise to build your own kernel with only the drivers you
   need, as this cuts down on the kernel size (saving your precious RAM
   for applications!) and reduces the number of device probes that can
   upset sensitive hardware. Building a kernel is not as complicated as
   it sounds. You just have to answer yes or no to a bunch of questions
   about what drivers you want, and it does the rest.
  
   The next main cause is having another device using part of the I/O
   space that your card needs. Most cards are 16 or 32 bytes wide in I/O
   space. If your card is set at 0x300 and 32 bytes wide, then the driver
   will ask for 0x300-0x31f. If any other device driver has registered
   even one port anywhere in that range, the probe will not take place at
   that address and the driver will silently continue to the next of the
   probed addresses. So, after booting, do a cat /proc/ioports and verify
   that the full I/O space that the card will require is vacant.
  
   Another problem is having your card jumpered to an I/O address that
   isn't probed by default. The list of probed addresses for each driver
   is easily found just after the text comments in the driver source.
   Even if the I/O setting of your card is not in the list of probed
   addresses, you can supply it at boot (for in-kernel drivers) with the
   ether= command as described in ``Passing Ethernet Arguments...''
   Modular drivers can make use of the io= option in /etc/conf.modules to
   specify an address that isn't probed by default.
  
  
  
   2.8.3. 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. 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.
  
  
   2.8.4. PCI machine detects card but driver fails probe.
  
  
   Some PCI BIOSes may not enable all PCI cards at power-up, especially
   if the BIOS option `PNP OS' is enabled. This mis-feature is to support
   the current release of Windows which still uses some real-mode
   drivers. Either disable this option, or try and upgrade to a newer
   driver which has the code to enable a disabled card.
  
  
   2.8.5. Shared Memory ISA cards in PCI Machine do not work ( 0xffff )
  
  
   This will usually show up as reads of lots of 0xffff values. No
   shared memory cards of any type will work in a PCI machine unless you
   have the PCI ROM BIOS/CMOS SETUP configuration set properly. You have
   to set it to allow shared memory access from the ISA bus for the
   memory region that your card is trying to use. If you can't figure out
   which settings are applicable then ask your supplier or local computer
   guru. For AMI BIOS, there is usually a "Plug and Play" section where
   there will be an ``ISA Shared Memory Size'' and ``ISA Shared Memory
   Base'' settings. For cards like the wd8013 and SMC Ultra, change the
   size from the default of `Disabled' to 16kB, and change the base to
   the shared memory address of your card.
  
  
  
   2.8.6. Card seems to send data but never receives anything.
  
  
   Do a cat /proc/interrupts. A running total of the number of interrupt
   events your card generates will be in the list given from the above.
   If it is zero and/or doesn't increase when you try to use the card
   then there is probably a physical interrupt conflict with another
   device installed in the computer (regardless of whether or not the
   other device has a driver installed/available). Change the IRQ of one
   of the two devices to a free IRQ.
  
  
  
   2.8.7. Asynchronous Transfer Mode (ATM) Support
  
  
   Werner Almesberger has been working on ATM support for linux. He has
   been working with the Efficient Networks ENI155p board (Efficient
   Networks <http://www.efficient.com/>) and the Zeitnet ZN1221 board
   (Zeitnet <http://www.zeitnet.com/>).
  
   Werner says that the driver for the ENI155p is rather stable, while
   the driver for the ZN1221 is presently unfinished.
  
   Check the latest/updated status at the following URL:
  
   Linux ATM Support <http://lrcwww.epfl.ch/linux-atm/>
  
  
   2.8.8. Gigabyte Ethernet Support
  
  
   Is there any gigabyte ethernet support for Linux?
  
   Yes, there are currently at least two. A driver for the Packet
   Engines G-NIC PCI Gigabit Ethernet adapter is available in the v2.0
   and v2.2 kernels For more details, support, and driver updates, see:
  
   http://www.scyld.com/linux/drivers/yellowfin.html
  
   The acenic.c driver available in the v2.2 kernels can be used for the
   Alteon AceNIC Gigabit Ethernet card and other Tigon based cards such
   as the 3Com 3c985. The driver should also work on the NetGear GA620,
   however this has yet to be verified.
  
  
   2.8.9. FDDI Support
  
   Is there FDDI support for Linux?
  
   Yes. Larry Stefani has written a driver for v2.0 with Digital's DEFEA
   (FDDI EISA) and DEFPA (FDDI PCI) cards. This was included into the
   v2.0.24 kernel. Currently no other cards are supported though.
  
  
   2.8.10. Full Duplex Support
  
  
   Will Full Duplex give me 20MBps? Does Linux support it?
  
   Cameron Spitzer writes the following about full duplex 10Base-T cards:
   ``If you connect it to a full duplex switched hub, and your system is
   fast enough and not doing much else, it can keep the link busy in both
   directions. There is no such thing as full duplex 10BASE-2 or
   10BASE-5 (thin and thick coax). Full Duplex works by disabling
   collision detection in the adapter. That's why you can't do it with
   coax; the LAN won't run that way. 10BASE-T (RJ45 interface) uses
   separate wires for send and receive, so it's possible to run both ways
   at the same time. The switching hub takes care of the collision
   problem. The signalling rate is 10 Mbps.''
  
   So as you can see, you still will only be able to receive or transmit
   at 10Mbps, and hence don't expect a 2x performance increase. As to
   whether it is supported or not, that depends on the card and possibly
   the driver. Some cards may do auto-negotiation, some may need driver
   support, and some may need the user to select an option in a card's
   EEPROM configuration. Only the serious/heavy user would notice the
   difference between the two modes anyway.
  
  
   2.8.11. Ethernet Cards for Linux on SMP Machines
  
  
   If you spent the extra money on a multi processor (MP) computer then
   buy a good ethernet card as well. For v2.0 kernels it wasn't really an
   issue, but it definitely is for v2.2. Most of the older non-
   intelligent (e.g. ISA bus PIO and shared memory design) cards were
   never designed with any consideration for use on a MP machine. The
   executive summary is to buy an intelligent modern design card and make
   sure the driver has been written (or updated) to handle MP operation.
   (The key words here are `modern design' - the PCI-NE2000's are just a
   10+ year old design on a modern bus.) Looking for the text spin_lock
   in the driver source is a good indication that the driver has been
   written to deal with MP operation. The full details of why you should
   buy a good card for MP use (and what happens if you dont) follow.
  
   In v2.0 kernels, only one processor was allowed `in kernel' (i.e.
   changing kernel data and/or running device drivers) at any given time.
   So from the point of view of the card (and the associated driver)
   nothing was different from uni processor (UP) operation and things
   just continued to work. (This was the easiest way to get a working MP
   version of Linux - one big lock around the whole kernel only allows
   one processor in at a time. This way you know that you won't have two
   processors trying to change the same thing at the same time!)
  
   The downside to only allowing one processor in the kernel at a time
   was that you only got MP performance if the running programs were self
   contained and calculation intensive. If the programs did a lot of
   input/output (I/O) such as reading or writing data to disk or over a
   network, then all but one of the processors would be stalled waiting
   on their I/O requests to be completed while the one processor running
   in kernel frantically tries to run all the device drivers to fill the
   I/O requests. The kernel becomes the bottleneck and since there is
   only one processor running in the kernel, the performance of a MP
   machine in the heavy I/O, single-lock case quickly degrades close to
   that of a single processor machine.
  
   Since this is clearly less than ideal (esp. for file/WWW servers,
   routers, etc.) the v2.2 kernels have finer grained locking - meaning
   that more than one processor can be in the kernel at a time. Instead
   of one big lock around the whole kernel, there are a lot of smaller
   locks protecting critical data from being manipulated by more than one
   processor at a time - e.g. one processor can be running the driver for
   the network card, while another processor is running the driver for
   the disk drive at the same time.
  
   Okay, with that all in mind here are the snags: The finer locking
   means that you can have one processor trying to send data out through
   an ethernet driver while another processor tries to access the same
   driver/card to do something else (such as get the card statistics for
   cat /proc/net/dev). Oops - your card stats just got sent out over the
   wire, while you got data for your stats instead. Yes, the card got
   confused by being asked to do two (or more!) things at once, and
   chances are it crashed your machine in the process.
  
   So, the driver that worked for UP is no longer good enough - it needs
   to be updated with locks that control access to the underlying card
   so that the three tasks of receive, transmit and manipulation of
   configuration data are serialized to the degree required by the card
   for stable operation. The scary part here is that a driver not yet
   updated with locks for stable MP operation will probably appear to be
   working in a MP machine under light network load, but will crash the
   machine or at least exhibit strange behaviour when two (or more!)
   processors try to do more than one of these three tasks at the same
   time.
  
   The updated MP aware ethernet driver will (at a minimum) require a
   lock around the driver that limits access at the entry points from the
   kernel into the driver to `one at a time please'. With this in place,
   things will be serialized so that the underlying hardware should be
   treated just as if it was being used in a UP machine, and so it should
   be stable. The downside is that the one lock around the whole ethernet
   driver has the same negative performance implications that having one
   big lock around the whole kernel had (but on a smaller scale) - i.e.
   you can only have one processor dealing with the card at a time.
   [Technical Note: The performance impact may also include increased
   interrupt latencies if the locks that need to be added are of the
   irqsave type and they are held for a long time.]
  
   Possible improvements on this situation can be made in two ways. You
   can try to minimize the time between when the lock is taken and when
   it is released, and/or you can implement finer grained locking within
   the driver (e.g. a lock around the whole driver would be overkill if a
   lock or two protecting against simultaneous access to a couple of
   sensitive registers/settings on the card would suffice).
  
   However, for older non-intelligent cards that were never designed with
   MP use in mind, neither of these improvements may be feasible. Worse
   yet is that the non-intelligent cards typically require the processor
   to move the data between the card and the computer memory, so in a
   worst case scenario the lock will be held the whole time that it takes
   to move each 1.5kB data packet over an ISA bus.
  
   The more modern intelligent cards typically move network data directly
   to and from the computer memory without any help from a processor.
   This is a big win, since the lock is then only held for the short time
   it takes the processor to tell the card where in memory to get/store
   the next network data packet. More modern card designs are less apt to
   require a single big lock around the whole driver as well.
  
  
  
   2.8.12. Ethernet Cards for Linux on Alpha/AXP PCI Boards
  
  
   As of v2.0, only the 3c509, depca, de4x5, pcnet32, and all the 8390
   drivers (wd, smc-ultra, ne, 3c503, etc.) have been made `architecture
   independent' so as to work on the DEC Alpha CPU based systems. Other
   updated PCI drivers from Donald's WWW page may also work as these have
   been written with architecture independence in mind.
  
   Note that the changes that are required to make a driver architecture
   independent aren't that complicated. You only need to do the
   following:
  
   -multiply all jiffies related values by HZ/100 to account for the
   different HZ value that the Alpha uses. (i.e timeout=2; becomes
   timeout=2*HZ/100;)
  
   -replace any I/O memory (640k to 1MB) pointer dereferences with the
   appropriate readb() writeb() readl() writel() calls, as shown in this
   example.
  
  
   ______________________________________________________________________
   - int *mem_base = (int *)dev->mem_start;
   - mem_base[0] = 0xba5eba5e;
   + unsigned long mem_base = dev->mem_start;
   + writel(0xba5eba5e, mem_base);
   ______________________________________________________________________
  
  
  
   -replace all memcpy() calls that have I/O memory as source or target
   destinations with the appropriate one of memcpy_fromio() or
   memcpy_toio().
  
   Details on handling memory accesses in an architecture independent
   fashion are documented in the file linux/Documentation/IO-mapping.txt
   that comes with recent kernels.
  
  
   2.8.13. Ethernet for Linux on SUN/Sparc Hardware.
  
   For the most up to date information on Sparc stuff, try the following
   URL:
  
   Linux Sparc <http://www.geog.ubc.ca/sparc>
  
   Note that some Sparc ethernet hardware gets its MAC address from the
   host computer, and hence you can end up with multiple interfaces all
   with the same MAC address. If you need to put more than one interface
   on the same net then use the hw option to ifconfig to assign unique
   MAC address.
  
   Issues regarding porting PCI drivers to the Sparc platform are similar
   to those mentioned above for the AXP platform. In addition there may
   be some endian issues, as the Sparc is big endian, and the AXP and
   ix86 are little endian.
  
  
   2.8.14. Ethernet for Linux on Other Hardware.
  
   There are several other hardware platforms that Linux can run on, such
   as Atari/Amiga (m68k). As in the Sparc case it is best to check with
   the home site of each Linux port to that platform to see what is
   currently supported. (Links to such sites are welcome here - send
   them in!)
  
  
   2.8.15. Linking 10 or 100 BaseT without a Hub
  
   Can I link 10/100BaseT (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.
  
  
   2.8.16. SIOCSIFxxx: No such device
  
   I get a bunch of `SIOCSIFxxx: No such device' messages at boot,
   followed by a `SIOCADDRT: Network is unreachable' What is wrong?
  
   Your ethernet device was not detected at boot/module insertion time,
   and when ifconfig and route are run, they have no device to work with.
   Use dmesg | more to review the boot messages and see if there are any
   messages about detecting an ethernet card.
  
  
   2.8.17. 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.
  
  
   2.8.18. Using `ifconfig' and Link UNSPEC with 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.
  
   You may also get strange information if the ifconfig program you are
   using is a lot older than the kernel you are using.
  
  
   2.8.19. 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.
  
  
   2.8.20. 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.
  
  
   2.8.21. 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.
  
  
  
   2.8.22. Access to the raw Ethernet Device
  
   How do I get access to the raw ethernet device in linux, without going
   through TCP/IP and friends?
  
  
   ______________________________________________________________________
   int s=socket(AF_INET,SOCK_PACKET,htons(ETH_P_ALL));
   ______________________________________________________________________
  
  
  
   This gives you a socket receiving 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 via sendto()
   calls. You have to have root access to do either of course.
  
  
   3. Performance Tips
  
   Here are some tips that you can use if you are suffering from low
   ethernet throughput, or to gain a bit more speed on those ftp
   transfers.
  
   The ttcp.c program is a good test for measuring raw throughput speed.
   Another common trick is to do a ftp> get large_file /dev/null where
   large_file is > 1MB and residing in the buffer cache on the Tx'ing
   machine. (Do the `get' at least twice, as the first time will be
   priming the buffer cache on the Tx'ing machine.) You want the file in
   the buffer cache because you are not interested in combining the file
   access speed from the disk into your measurement. Which is also why
   you send the incoming data to /dev/null instead of onto the disk.
  
  
   3.1. General Concepts
  
   Even an 8 bit card is able to receive back-to-back packets without any
   problems. The difficulty arises when the computer doesn't get the Rx'd
   packets off the card quick enough to make room for more incoming
   packets. If the computer does not quickly clear the card's memory of
   the packets already received, the card will have no place to put the
   new packet.
  
  
   In this case the card either drops the new packet, or writes over top
   of a previously received packet. Either one seriously interrupts the
   smooth flow of traffic by causing/requesting re-transmissions and can
   seriously degrade performance by up to a factor of 5!
  
   Cards with more onboard memory are able to ``buffer'' more packets,
   and thus can handle larger bursts of back-to-back packets without
   dropping packets. This in turn means that the card does not require
   as low a latency from the the host computer with respect to pulling
   the packets out of the buffer to avoid dropping packets.
  
   Most 8 bit cards have an 8kB buffer, and most 16 bit cards have a 16kB
   buffer. Most Linux drivers will reserve 3kB of that buffer (for two Tx
   buffers), leaving only 5kB of receive space for an 8 bit card. This is
   room enough for only three full sized (1500 bytes) ethernet packets.
  
  
   3.2. ISA Cards and ISA Bus Speed
  
   As mentioned above, if the packets are removed from the card fast
   enough, then a drop/overrun condition won't occur even when the amount
   of Rx packet buffer memory is small. The factor that sets the rate at
   which packets are removed from the card to the computer's memory is
   the speed of the data path that joins the two -- that being the ISA
   bus speed. (If the CPU is a dog-slow 386sx-16, then this will also
   play a role.)
  
   The recommended ISA bus clock is about 8MHz, but many motherboards and
   peripheral devices can be run at higher frequencies. The clock
   frequency for the ISA bus can usually be set in the CMOS setup, by
   selecting a divisor of the mainboard/CPU clock frequency. Some ISA and
   PCI/ISA mainboards may not have this option, and so you are stuck with
   the factory default.
  
   For example, here are some receive speeds as measured by the TTCP
   program on a 40MHz 486, with an 8 bit WD8003EP card, for different
   ISA bus speeds.
  
  
   ______________________________________________________________________
   ISA Bus Speed (MHz) Rx TTCP (kB/s)
   ------------------- --------------
   6.7 740
   13.4 970
   20.0 1030
   26.7 1075
   ______________________________________________________________________
  
  
  
   You would be hard pressed to do better than 1075kB/s with any 10Mb/s
   ethernet card, using TCP/IP. However, don't expect every system to
   work at fast ISA bus speeds. Most systems will not function properly
   at speeds above 13MHz. (Also, some PCI systems have the ISA bus speed
   fixed at 8MHz, so that the end user does not have the option of
   increasing it.)
  
   In addition to faster transfer speeds, one will usually also benefit
   from a reduction in CPU usage due to the shorter duration memory and
   I/O cycles. (Note that hard disks and video cards located on the ISA
   bus will also usually experience a performance increase from an
   increased ISA bus speed.)
  
   Be sure to back up your data prior to experimenting with ISA bus
   speeds in excess of 8MHz, and thouroughly test that all ISA
   peripherals are operating properly after making any speed increases.
   3.3. Setting the TCP Rx Window
  
  
   Once again, cards with small amounts of onboard RAM and relatively
   slow data paths between the card and the computer's memory run into
   trouble. The default TCP Rx window setting is 32kB, which means that a
   fast computer on the same subnet as you can dump 32k of data on you
   without stopping to see if you received any of it okay.
  
   Recent versions of the route command have the ability to set the size
   of this window on the fly. Usually it is only for the local net that
   this window must be reduced, as computers that are behind a couple of
   routers or gateways are `buffered' enough to not pose a problem. An
   example usage would be:
  
  
   ______________________________________________________________________
   route add <whatever> ... window <win_size>
   ______________________________________________________________________
  
  
  
   where win_size is the size of the window you wish to use (in bytes).
   An 8 bit 3c503 card on an ISA bus operating at a speed of 8MHz or less
   would work well with a window size of about 4kB. Too large a window
   will cause overruns and dropped packets, and a drastic reduction in
   ethernet throughput. You can check the operating status by doing a cat
   /proc/net/dev which will display any dropped or overrun conditions
   that occurred.
  
  
   3.4. Increasing NFS performance
  
   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 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 2kB (or even 1kB), or try increasing the ISA bus
   speed in order to get the card's buffer cleared out faster. I have
   found that an old WD8003E card at 8MHz (with no other system load) can
   keep up with a large receive at 2kB NFS size, but not at 4kB, where
   performance was degraded by a factor of three.
  
   On the other hand, if the default mount option is to use 1kB size and
   you have at least a 16 bit ISA card, you may find a significant
   increase in going to 4kB (or even 8kB).
  
  
   4. Vendor/Manufacturer/Model Specific Information
  
  
   The following lists many cards in alphabetical order by vendor name
   and then product identifier. Beside each product ID, you will see
   either `Supported', `Semi-Supported' or `Not Supported'.
  
   Supported means that a driver for that card exists, and many people
   are happily using it and it seems quite reliable.
   Semi-Supported means that a driver exists, but at least one of the
   following descriptions is true: (1) The driver and/or hardware are
   buggy, which may cause poor performance, failing connections or even
   crashes. (2) The driver is new or the card is fairly uncommon, and
   hence the driver has seen very little use/testing and the driver
   author has had very little feedback. Obviously (2) is preferable to
   (1), and the individual description of the card/driver should make it
   clear which one holds true. In either case, you will probably have to
   answer `Y' when asked ``Prompt for development and/or incomplete
   code/drivers?'' when running make config.
  
   Not Supported means there is not a driver currently available for that
   card. This could be due to a lack of interest in hardware that is
   rare/uncommon, or because the vendors won't release the hardware
   documentation required to write a driver.
  
   Note that the difference between `Supported' and `Semi-Supported' is
   rather subjective, and is based on user feedback observed in newsgroup
   postings and mailing list messages. (After all, it is impossible for
   one person to test all drivers with all cards for each kernel
   version!!!) So be warned that you may find a card listed as semi-
   supported works perfectly for you (which is great), or that a card
   listed as supported gives you no end of troubles and problems (which
   is not so great).
  
   After the status, the name of the driver given in the linux kernel is
   listed. This will also be the name of the driver module that would be
   used in the alias eth0 driver_name line that is found in the
   /etc/conf.modules module configuration file.
  
  
  
   4.1. 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 WWW/FTP site with various goodies:
   www.3Com.com that you may want to check out. They even have linux
   drivers for some of their cards there you may wish to test out. It
   has been reported that their drivers are not stable and/or unuseable
   on SMP and non ix86 based machines, so you may want to keep that in
   mind.
  
  
  
   4.1.1. 3c501
  
   Status: Semi-Supported, Driver Name: 3c501
  
   This obsolete stone-age 8 bit card is really too brain-damaged to use.
   Avoid it like the plague. Do not purchase this card, even as a joke.
   It's performance is horrible, and it breaks in many ways.
  
   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.
  
   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.
  
  
   4.1.2. EtherLink II, 3c503, 3c503/16
  
   Status: Supported, Driver Name: 3c503 (+8390)
  
   The 3c503 does not have ``EEPROM setup'', so a 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.
  
   These cards should be about the same speed as the same bus width
   WD80x3, but turn out to be actually a bit slower. These shared-memory
   ethercards also have a programmed I/O mode that doesn't use the 8390
   facilities (their engineers found too many bugs!) The Linux 3c503
   driver can also work with the 3c503 in programmed-I/O mode, but this
   is slower and less reliable than shared memory mode. Also, programmed-
   I/O mode is not as well tested when updating the drivers. You
   shouldn't use the programmed-I/O mode 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...''.
  
   If you intend on using this driver as a loadable module you should
   probably see ``Using the Ethernet Drivers as Modules'' for module
   specific information.
  
   Note that some old diskless 386 workstations have an on board 3c503
   (made by 3Com and sold under different names, like `Bull') but the
   vendor ID is not a 3Com ID and so it won't be detected. More details
   can be found in the Etherboot package, which you will need anyways to
   boot these diskless boxes.
  
  
   4.1.3. Etherlink Plus 3c505
  
   Status: Semi-Supported, Driver Name: 3c505
  
   These cards use the i82586 chip but are not that many of them 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.
  
  
  
   4.1.4. Etherlink-16 3c507
  
   Status: Semi-Supported, Driver Name: 3c507
  
   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.
  
  
   4.1.5. Etherlink III, 3c509 / 3c509B
  
   Status: Supported, Driver Name: 3c509
  
   This card is fairly inexpensive and has good performance for an ISA
   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.) These
   cards use PIO transfers, similar to a ne2000 card, and so a shared
   memory card such as a wd8013 will be more efficient in comparison.
  
   The original 3c509 has a small packet buffer (4kB total, 2kB Rx, 2kB
   Tx), 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 man hdparm) and/or
   increasing your ISA bus speed so IDE transfers finish sooner.
  
   The newer model 3c509B has 8kB on board, and the buffer can be split
   4/4, 5/3 or 6/2 for Rx/Tx. This setting is changed with the DOS
   configuration utility, and is stored on the EEPROM. This should
   alleviate the above problem with the original 3c509.
  
   3c509B users should use either the supplied DOS utility to disable the
   plug and play support, and to set the output media to what they
   require. The linux driver currently does not support the Autodetect
   media setting, so you have to select 10Base-T or 10Base-2 or AUI.
   Note that to turn off PnP entirely, you should do a 3C5X9CFG
   /PNP:DISABLE and then follow that with a hard reset to ensure that it
   takes effect.
  
   Some people ask about the ``Server or Workstation'' and ``Highest
   Modem Speed'' settings presented in the DOS configuration utility.
   Donald writes ``These are only hints to the drivers, and the Linux
   driver does not use these parameters: it always optimizes for high
   throughput rather than low latency (`Server'). Low latency was
   critically important for old, non-windowed, IPX throughput. To reduce
   the latency the MS-DOS driver for the 3c509 disables interrupts for
   some operations, blocking serial port interrupts. Thus the need for
   the `modem speed' setting. The Linux driver avoids the need to
   disable interrupts for long periods by operating only on whole packets
   e.g. by not starting to transmit a packet until it is completely
   transferred to the card.''
  
   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 to 0x1ff on intervals of 0x10). This detection
   method means that a particular card will always get detected first in
   a multiple ISA 3c509 configuration. The card with the lowest hardware
   ethernet address will always 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. If you have multiple
   3c509 cards, it is best to append ether=0,0,ethN commands without the
   I/O port specified (i.e. use I/O=zero) and allow the probe to sort out
   which card is first. Using a non-zero I/O value will ensure that it
   does not detect all your cards, so don't do it.
   If this really bothers you, have a look at Donald's latest driver, as
   you may be able to use a 0x3c509 value in the unused mem address
   fields to order the detection to suit your needs.
  
  
   4.1.6. 3c515
  
   Status: Supported, Driver Name: 3c515
  
   This is 3Com's ISA 100Mbps offering, codenamed ``CorkScrew''. A
   relatively new driver from Donald for these cards is included in the
   v2.2 kernels. For the most up to date information, you should
   probably look on the Vortex page:
  
   Vortex <http://www.scyld.com/linux/drivers/vortex.html>
  
  
  
   4.1.7. 3c523
  
   Status: Semi-Supported, Driver Name: 3c523
  
   This MCA bus card uses the i82586, and Chris Beauregard has modified
   the ni52 driver to work with these cards. The driver for it can be
   found in the v2.2 kernel source tree.
  
   More details can be found on the MCA-Linux page at
   http://glycerine.cetmm.uni.edu/mca/
  
  
   4.1.8. 3c527
  
   Status: Not Supported.
  
   Yes, another MCA card. No, not too much interest in it. Better
   chances with the 3c529 if you are stuck with MCA.
  
  
   4.1.9. 3c529
  
   Status: Supported, Driver Name: 3c509
  
   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, long before
   MCA support was added to the kernel. The required MCA probe code is
   included in the driver shipped with v2.2 kernels. More details can be
   found on the MCA-Linux page at:
  
   http://glycerine.cetmm.uni.edu/mca/
  
  
   4.1.10. 3c562
  
   Status: Supported, Driver Name: 3c589 (distributed separately)
  
   This PCMCIA card is the combination of a 3c589B ethernet card with a
   modem. The modem appears as a standard modem to the end user. The only
   difficulty is getting the two separate linux drivers to share one
   interrupt. There are a couple of new registers and some hardware
   interrupt sharing support. You need to use a v2.0 or newer kernel
   that has the support for interrupt sharing.
  
  
   Thanks again to Cameron for getting a sample unit and documentation
   sent off to David Hinds. Look for support in David's PCMCIA package
   release.
  
   See ``PCMCIA Support'' for more info on PCMCIA chipsets, socket
   enablers, etc.
  
  
   4.1.11. 3c575
  
   Status: Unknown.
  
   A driver for this PCMCIA card is under development and hopefully will
   be included in David's PCMCIA package in the future. Best to check
   the PCMCIA package to get the current status.
  
  
  
   4.1.12. 3c579
  
   Status: Supported, Driver Name: 3c509
  
   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. Make sure the card is configured for EISA
   addressing mode. Read the above 3c509 section for info on the driver.
  
  
  
   4.1.13. 3c589 / 3c589B
  
   Status: Semi-Supported, Driver Name: 3c589
  
   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. The "B" in the name means the same here as it
   does for the 3c509 case.
  
   There are drivers available on Donald's ftp site and in David Hinds
   PCMCIA package. You will also need a supported PCMCIA controller
   chipset. See ``PCMCIA Support'' for more info on PCMCIA drivers,
   chipsets, socket enablers, etc.
  
  
   4.1.14. 3c590 / 3c595
  
   Status: Supported, Driver Name: 3c59x
  
   These ``Vortex'' cards are for PCI bus machines, with the '590 being
   10Mbps and the '595 being 3Com's 100Mbs offering. Also note that you
   can run the '595 as a '590 (i.e. in a 10Mbps mode). The driver is
   included in the v2.0 kernel source, but is also continually being
   updated. If you have problems with the driver in the v2.0 kernel, you
   can get an updated driver from the following URL:
  
   Vortex <http://www.scyld.com/linux/drivers/vortex.html>
  
   Note that there are two different 3c590 cards out there, early models
   that had 32kB of on-board memory, and later models that only have 8kB
   of memory. Chances are you won't be able to buy a new 3c59x for much
   longer, as it is being replaced with the 3c90x card. If you are buying
   a used one off somebody, try and get the 32kB version. The 3c595 cards
   have 64kB, as you can't get away with only 8kB RAM at 100Mbps!
  
   A thanks to Cameron Spitzer and Terry Murphy of 3Com for sending cards
   and documentation to Donald so he could write the driver.
  
  
   4.1.15. 3c592 / 3c597
  
   Status: Supported, Driver Name: 3c59x
  
   These are the EISA versions of the 3c59x series of cards. The
   3c592/3c597 (aka Demon) should work with the vortex driver discussed
   above.
  
  
   4.1.16. 3c900 / 3c905 / 3c905B / 3c905C
  
   Status: Supported, Driver Name: 3c59x
  
   These cards (aka `Boomerang', aka EtherLink III XL) have been released
   to take over the place of the 3c590/3c595 cards.
  
   The support for the Cyclone `B' revision was only recently added. To
   use this card with older v2.0 kernels, you must obtain the updated
   3c59x.c driver from Donald's site at:
  
   Vortex-Page <http://www.scyld.com/network>
  
  
  
   4.1.17. 3c985
  
   Status: Supported, Driver Name: acenic
  
   This driver, by Jes Sorensen, is available in v2.2 kernels It supports
   several other Gigabit cards in addition to the 3Com model.
  
  
   4.2. Accton