diff --git a/FAQ/hackers.sgml b/FAQ/hackers.sgml index 7099239ffb..cbe0a17623 100644 --- a/FAQ/hackers.sgml +++ b/FAQ/hackers.sgml @@ -1,581 +1,581 @@ - + For serious FreeBSD hackers only What are SNAPs and RELEASEs?

There are currently three active/semi-active branches in the FreeBSD :

Right now, The The How do I make my own custom release?

To make a release you need to do three things: First, you need to be running a kernel with the driver configured in. Add this to your kernel config file and build a new kernel: pseudo-device vn #Vnode driver (turns a file into a device)

Second, you have to have the whole CVS repository at hand. - To get this you can use + To get this you can use but in your supfile set the release name to cvs and remove any tag or date fields: *default prefix=/home/ncvs *default base=/a *default host=cvsup.FreeBSD.org *default release=cvs *default delete compress use-rel-suffix ## Main Source Tree src-all src-eBones src-secure # Other stuff ports-all www doc-all

Then run Finally, you need a chunk of empty space to build into. Let's say it's in /some/big/filesystem, and from the example above you've got the CVS repository in /home/ncvs: setenv CVSROOT /home/ncvs # or export CVSROOT=/home/ncvs cd /usr/src/release make release BUILDNAME=3.0-MY-SNAP CHROOTDIR=/some/big/filesystem/release

An entire release will be built in /some/big/filesystem/release and you will have a full FTP-type installation in /some/big/filesystem/release/R/ftp when you're done. If you want to build your SNAP along some other branch than -current, you can also add How do I create customized installation disks?

The entire process of creating installation disks and source and binary archives is automated by various targets in /usr/src/release/Makefile. The information there should be enough to get you started. However, it should be said that this involves doing a ``make world'' and will therefore take up a lot of time and disk space. ``make world'' clobbers my existing installed binaries.

Yes, this is the general idea; as its name might suggest, ``make world'' rebuilds every system binary from scratch, so you can be certain of having a clean and consistent environment at the end (which is why it takes so long).

If the environment variable ${DESTDIR}. Some random combination of shared libraries modifications and program rebuilds can cause this to fail in `` When my system boots, it says ``(bus speed defaulted)''.

The Adaptec 1542 SCSI host adapters allow the user to configure their bus access speed in software. Previous versions of the 1542 driver tried to determine the fastest usable speed and set the adapter to that. We found that this breaks some users' systems, so you now have to define the `` Can I follow current with limited Internet access?

Yes, you can do this + by using the How did you split the distribution into 240k files?

Newer BSD based systems have a ``Here is an example from /usr/src/Makefile. bin-tarball: (cd ${DISTDIR}; \ tar cf - . \ gzip --no-name -9 -c | \ split -b 240640 - \ ${RELEASEDIR}/tarballs/bindist/bin_tgz.) I've written a kernel extension, who do I send it to?

Please take a look at

And thanks for the thought! How are Plug N Play ISA cards detected and initialized?

By:

In a nutshell, there a few I/O ports that all of the PnP boards respond to when the host asks if anyone is out there. So when the PnP probe routine starts, he asks if there are any PnP boards present, and all the PnP boards respond with their model # to a I/O read of the same port, so the probe routine gets a wired-OR ``yes'' to that question. At least one bit will be on in that reply. Then the probe code is able to cause boards with board model IDs (assigned by Microsoft/Intel) lower than X to go ``off-line''. It then looks to see if any boards are still responding to the query. If the answer was ``The IDs are two 32-bit fields (hence 2ˆ64) + 8 bit checksum. The first 32 bits are a vendor identifier. They never come out and say it, but it appears to be assumed that different types of boards from the same vendor could have different 32-bit vendor ids. The idea of needing 32 bits just for unique manufacturers is a bit excessive.

The lower 32 bits are a serial #, ethernet address, something that makes this one board unique. The vendor must never produce a second board that has the same lower 32 bits unless the upper 32 bits are also different. So you can have multiple boards of the same type in the machine and the full 64 bits will still be unique.

The 32 bit groups can never be all zero. This allows the wired-OR to show non-zero bits during the initial binary search.

Once the system has identified all the board IDs present, it will reactivate each board, one at a time (via the same I/O ports), and find out what resources the given board needs, what interrupt choices are available, etc. A scan is made over all the boards to collect this information.

This info is then combined with info from any ECU files on the hard disk or wired into the MLB BIOS. The ECU and BIOS PnP support for hardware on the MLB is usually synthetic, and the peripherals don't really do genuine PnP. However by examining the BIOS info plus the ECU info, the probe routines can cause the devices that are PnP to avoid those devices the probe code cannot relocate.

Then the PnP devices are visited once more and given their I/O, DMA, IRQ and Memory-map address assignments. The devices will then appear at those locations and remain there until the next reboot, although there is nothing that says you can't move them around whenever you want.

There is a lot of oversimplification above, but you should get the general idea.

Microsoft took over some of the primary printer status ports to do PnP, on the logic that no boards decoded those addresses for the opposing I/O cycles. I found a genuine IBM printer board that did decode writes of the status port during the early PnP proposal review period, but MS said ``tough''. So they do a write to the printer status port for setting addresses, plus that use that address + Does FreeBSD support architectures other than the x86?

Several groups of people have expressed interest in working on multi-architecture ports for FreeBSD and the FreeBSD/AXP (ALPHA) port is one such effort which has been quite successful, now available in 3.0 SNAPshot release form at . The ALPHA port currently runs on a growing number of ALPHA machine types, among them the AlphaStation, AXPpci, PC164, Miata and Multia models. This port is not yet considered a full release and won't be until a full compliment of system installation tools and a distribution on CDROM installation media is available, including a reasonable number of working ports and packages. FreeBSD/AXP should be considered BETA quality software at this time. For status information, please join the <freebsd-alpha@FreeBSD.ORG>. Interest has also been expressed in a port of FreeBSD to the SPARC architecture, join the <freebsd-sparc@FreeBSD.ORG> if you are interested in joining that project. For general discussion on new architectures, join the <freebsd-platforms@FreeBSD.ORG> . I need a major number for a device driver I've written.

This depends on whether or not you plan on making the driver publicly available. If you do, then please send us a copy of the driver source code, plus the appropriate modifications to files.i386, a sample configuration file entry, and the appropriate code to create any special files your device uses. If you do not, or are unable to because of licensing restrictions, then character major number 32 and block major number 8 have been reserved specifically for this purpose; please use them. In any case, we'd appreciate hearing about your driver on <freebsd-hackers@FreeBSD.ORG>. Alternative layout policies for directories

In answer to the question of alternative layout policies for directories, the scheme that is currently in use is unchanged from what I wrote in 1983. I wrote that policy for the original fast filesystem, and never revisited it. It works well at keeping cylinder groups from filling up. As several of you have noted, it works poorly for find. Most filesystems are created from archives that were created by a depth first search (aka ftw). These directories end up being striped across the cylinder groups thus creating a worst possible senario for future depth first searches. If one knew the total number of directories to be created, the solution would be to create (total / fs_ncg) per cylinder group before moving on. Obviously, one would have to create some heuristic to guess at this number. Even using a small fixed number like say 10 would make an order of magnitude improvement. To differentiate restores from normal operation (when the current algorithm is probably more sensible), you could use the clustering of up to 10 if they were all done within a ten second window. Anyway, my conclusion is that this is an area ripe for experimentation.

Kirk McKusick, September 1998

Making the most of a kernel panic

[This section was extracted from a mail written by on the freebsd-current by , who fixed a few typos and added the bracketed comments]

From: Bill Paul Subject: Re: the fs fun never stops To: ben@rosengart.com Date: Sun, 20 Sep 1998 15:22:50 -0400 (EDT) Cc: current@FreeBSD.ORG

[<ben@rosengart.com> posted the following panic message] > Fatal trap 12: page fault while in kernel mode > fault virtual address = 0x40 > fault code = supervisor read, page not present > instruction pointer = 0x8:0xf014a7e5 ^^^^^^^^^^ > stack pointer = 0x10:0xf4ed6f24 > frame pointer = 0x10:0xf4ed6f28 > code segment = base 0x0, limit 0xfffff, type 0x1b > = DPL 0, pres 1, def32 1, gran 1 > processor eflags = interrupt enabled, resume, IOPL = 0 > current process = 80 (mount) > interrupt mask = > trap number = 12 > panic: page fault

[When] you see a message like this, it's not enough to just reproduce it and send it in. The instruction pointer value that I highlighted up there is important; unfortunately, it's also configuration dependent. In other words, the value varies depending on the exact kernel image that you're using. If you're using a GENERIC kernel image from one of the snapshots, then it's possible for somebody else to track down the offending function, but if you're running a custom kernel then only What you should do is this: Write down the instruction pointer value. Note that the When the system reboots, do the following: % nm /kernel.that.caused.the.panic | grep f0xxxxxx where % nm /kernel.that.caused.the.panic | grep f0xxxxx If that doesn't yield any results, chop off another digit. Repeat until you get some sort of output. The result will be a possible list of functions which caused the panic. This is a less than exact mechanism for tracking down the point of failure, but it's better than nothing.

I see people constantly show panic messages like this but rarely do I see someone take the time to match up the instruction pointer with a function in the kernel symbol table.

The best way to track down the cause of a panic is by capturing a crash dump, then using In any case, the method I normally use is this: Set up a kernel config file, optionally adding 'options DDB' if you think you need the kernel debugger for something. (I use this mainly for setting beakpoints if I suspect an infinite loop condition of some kind.) Use cd /sys/compile/KERNELCONFIG; make Wait for kernel to finish compiling. cp kernel / reboot

[Note: Now that FreeBSD 3.x kernels are Elf by default, you should use

Note that YOU DO To make sure you capture a crash dump, you need edit /etc/rc.conf and set /etc/rc.conf, the /var/crash.

NOTE: FreeBSD crash dumps are usually the same size as the physical RAM size of your machine. That is, if you have 64MB of RAM, you will get a 64MB crash dump. Therefore you must make sure there's enough space in /var/crash to hold the dump. Alternatively, you run Once you have recovered the crash dump, you can get a stack trace with % gdb -k /sys/compile/KERNELCONFIG/kernel.debug /var/crash/vmcore.0 (gdb) where

Note that there may be several screens worth of information; ideally you should use Now, if you're really insane and have a second computer, you can also configure [Bill adds: "I forgot to mention one thing: if you have DDB enabled and the kernel drops into the debugger, you can force a panic (and a crash dump) just by typing 'panic' at the ddb prompt. It may stop in the debugger again during the panic phase. If it does, type 'continue' and it will finish the crash dump." -ed] dlsym() stopped working for ELF executables!

The ELF toolchain does not, by default, make the symbols defined in an executable visible to the dynamic linker. Consequently dlsym() searches on handles obtained from calls to dlopen(NULL, flags) will fail to find such symbols.

If you want to search, using dlsym(), for symbols present in the main executable of a process, you need to link the executable using the -export-dynamic option to the . Increasing or reducing the kernel address space

By default, the kernel address space is 256 MB on FreeBSD 3.x and 1 GB on FreeBSD 4.x. If you run a network-intensive server (e.g. a large FTP or HTTP server), you might find that 256 MB is not enough.

So how do you increase the address space? There are two aspects to this. First, you need to tell the kernel to reserve a larger portion of the address space for itself. Second, since the kernel is loaded at the top of the address space, you need to lower the load address so it doesn't bump its head against the ceiling.

The first goal is achieved by increasing the value of src/sys/i386/include/pmap.h. Here's what it looks like for a 1 GB address space: #ifndef NKPDE #ifdef SMP #define NKPDE 254 /* addressable number of page tables/pde's */ #else #define NKPDE 255 /* addressable number of page tables/pde's */ #endif /* SMP */ #endif

To find the correct value of To achieve the second goal, you need to compute the correct load address: simply subtract the address space size (in bytes) from 0x100100000; the result is 0xc0100000 for a 1 GB address space. Set src/sys/i386/conf/Makefile.i386 to that value; then set the location counter in the beginning of the section listing to the same value, as follows: OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386") OUTPUT_ARCH(i386) ENTRY(btext) SEARCH_DIR(/usr/lib); SEARCH_DIR(/usr/obj/elf/home/src/tmp/usr/i386-unknown-freebsdelf/lib); SECTIONS { /* Read-only sections, merged into text segment: */ . = 0xc0100000 + SIZEOF_HEADERS; .interp : { *(.interp) }

Then reconfig and rebuild your kernel. You will probably have problems with /usr/include/vm/.

NOTE: the size of the kernel address space must be a multiple of four megabytes.

[ adds: I think the kernel address space needs to be a power of two, but I'm not certain about that. The old(er) boot code used to monkey with the high order address bits and I think expected at least 256MB granularity.] diff --git a/FAQ/hardware.sgml b/FAQ/hardware.sgml index 851457b77a..79ed262b04 100644 --- a/FAQ/hardware.sgml +++ b/FAQ/hardware.sgml @@ -1,408 +1,408 @@ - + Hardware compatibility What kind of hard drives does FreeBSD support?

FreeBSD supports EIDE and SCSI drives (with a compatible controller; see the next section), and all drives using the original "Western Digital" interface (MFM, RLL, ESDI, and of course IDE). A few ESDI controllers that use proprietary interfaces may not work: stick to WD1002/3/6/7 interfaces and clones. Which SCSI controllers are supported?

See the complete list in the - . Which CD-ROM drives are supported by FreeBSD?

Any SCSI drive connected to a supported controller is supported.

The following proprietary CD-ROM interfaces are also supported: Mitsumi LU002 (8bit), LU005 (16bit) and FX001D (16bit 2x Speed). Sony CDU 31/33A Sound Blaster Non-SCSI CD-ROM Matsushita/Panasonic CD-ROM ATAPI compatible IDE CD-ROMs

All non-SCSI cards are known to be extremely slow compared to SCSI drives, and some ATAPI CDROMs may not work.

As of 2.2 the FreeBSD CDROM from Walnut Creek supports booting directly from the CD. Does FreeBSD support ZIP drives?

FreeBSD supports the SCSI ZIP drive out of the box, of course. The ZIP drive can only be set to run at SCSI target IDs 5 or 6, but if your SCSI host adapter's BIOS supports it you can even boot from it. I don't know which host adapters let you boot from targets other than 0 or 1... look at your docs (and let me know if it works out for you).

ATAPI (IDE) Zip drives are supported in FreeBSD 2.2.6 and later releases.

FreeBSD 3.0-STABLE contains support for the parallel Zip However, you will need to build a new kernel with support for ppbus (Parallel Port Bus) in order to use the Zip. See the LINT configuration file for examples.

Also check out , and . Does FreeBSD support JAZ, EZ and other removable drives?

Apart from the IDE version of the EZ drive, these are all SCSI devices, so the should all look like SCSI disks to FreeBSD, and the IDE EZ should look like an IDE drive.

See . Which multi-port serial cards are supported by FreeBSD?

There is a list of these in the + url="../handbook/install.html#INSTALL-MISC" name="Miscellaneous devices"> section of the handbook.

Some unnamed clone cards have also been known to work, especially those that claim to be AST compatible.

Check the man page to get more information on configuring such cards. I have an unusual bus mouse. How do I set it up?

FreeBSD supports the bus mouse and the InPort bus mouse from such manufactures as Microsoft, Logitech and ATI. The bus device driver is compiled in the GENERIC kernel by default. If you are building a custom kernel with the bus mouse driver, make sure to add the following line to the kernel config file: device mse0 at isa? port 0x23c tty irq5 vector mseintr

The bus mouse usually comes with an dedicatd interface card. It may allow you to set the port address and the IRQ number other than shown above. Refer to the manual of your mouse and the man page for more information. How do I use my PS/2 (``mouse port'' or ``keyboard'') mouse?

If you're running a post-2.2.5 version of FreeBSD, the necessary driver, psm, is included and enabled in the kernel. The kernel should detect your PS/2 mouse at boot time.

If you're running a previous but relatively recent version of FreeBSD (2.1.x or better) then you can simply enable it in the kernel configuration menu at installation time, otherwise later with -c at the boot: prompt. It is disabled by default, so you will need to enable it explicitly.

If you're running an older version of FreeBSD then you'll have to add the following lines to your kernel configuration file and compile a new kernel: device psm0 at isa? port "IO_KBD" conflicts tty irq 12 vector psmintr

See the if you've no experience with building kernels.

Once you have a kernel detecting psm0 correctly at boot time, make sure that an entry for psm0 exists in /dev. You can do this by typing: cd /dev; sh MAKEDEV psm0

when logged in as root. Is it possible to make use of a mouse in any way outside the X Window?

If you are using the default console driver, syscons, you can use a mouse pointer in text consoles to cut & paste text. Run the mouse daemon, moused, and turn on the mouse pointer in the virtual console: moused -p /dev/xxxx -t yyyy vidcontrol -m on

Where xxxx is the mouse device name and yyyy is a protocol type for the mouse. See the man page for supported protocol types.

You may wish to run the mouse daemon automatically when the system starts. In version 2.2.1, set the following variables in /etc/sysconfig. mousedtype="yyyy" mousedport="xxxx" mousedflags="" In versions 2.2.2 or later, set the following variables in /etc/rc.conf. moused_type="yyyy" moused_port="xxxx" moused_flags=""

Staring from FreeBSD 2.2.6, the mouse daemon is capable of determining the correct protocol type automatically unless the mouse is a relatively old serial mouse model. Specify ``auto'' as the protocol to invoke automatic detection.

When the mouse daemon is running, access to the mouse needs to be coordinated between the mouse daemon and other programs such as the X Window. Refer to on this issue". How do I cut and paste text with mouse in the text console?

Once you get the mouse daemon running (see ), hold down the button 1 (left button) and move the mouse to select a region of text. Then, press the button 2 (middle button) or the button 3 (right button) to paste it at the text cursor.

In versions 2.2.6 and later, pressing the button 2 will paste the text. Pressing the button 3 will ``extend'' the selected region of text. If your mouse does not have the middle button, you may wish to emulate it or remap buttons using moused options. See the man page for details. My mouse has a fancy wheel and buttons. Can I use them in FreeBSD?

The answer is, unfortunately, ``It depends.'' These mice with additional features require specialized driver in most cases. Unless the mouse device driver or the user program has specific support for the mouse, it will act just like a standard two, or three button mouse. How do I use the mouse/trackball/touchpad on my laptop?

Please refer to . And check out on the Mobile Computing page. What types of tape drives are supported?

FreeBSD supports SCSI, QIC-36 (with a QIC-02 interface) and QIC-40/80 (Floppy based) tape drives. This includes 8-mm (aka Exabyte) and DAT drives. The QIC-40/80 drives are known to be slow.

Some of the early 8-mm drives are not quite compatible with SCSI-2, and may not work well with FreeBSD. Does FreeBSD support tape changers?

FreeBSD 2.2 supports SCSI changers using the device and the command. The details of how you actually control the changer can be found in the man page.

If you're not using or some other product that already understands changers, remember that they're only know how to move a tape from one point to another, so you need to keep track of which slot a tape is in, and which slot the tape currently in the drive needs to go back to. Which sound cards are supported by FreeBSD?

FreeBSD supports the SoundBlaster, SoundBlaster Pro, SoundBlaster 16, Pro Audio Spectrum 16, AdLib and Gravis UltraSound sound cards. There is also limited support for MPU-401 and compatible MIDI cards. Cards conforming to the Microsoft Sound System specification are also supported through the pcm driver.

Which network cards does FreeBSD support? -

See the See the section of the handbook for a more complete list. I don't have a math co-processor - is that bad?

In general this will not cause any problems, but there are circumstances where you will take a hit, either in performance or accuracy of the math emulation code (see the section ). In particular, drawing arcs in X will be VERY slow. It is highly recommended that you buy a math co-processor; it's well worth it.

What other devices does 2.X support? -

See the +

See the for the list of other devices supported. Does FreeBSD support power management on my laptop?

FreeBSD supports APM on certain machines. Please look in the keyword. Workarounds for specific hardware problems

This section contains workarounds for specific hardware problems encountered by our users. Micron systems hang at boot time

Certain Micron motherboards have a non-conforming PCI BIOS implementation that causes grief when FreeBSD boots because PCI devices don't get configured at their reported addresses.

Disable the "Plug and Play Operating System" flag in the BIOS to work around this problem. More information can be found at I have a newer Adaptec controller and FreeBSD can't find it.

The newer AIC789x series Adaptec chips are supported under the CAM SCSI framework which made it's debut in 3.0. Patches against 2.2-STABLE are in . A CAM-enhanced boot floppy is available at . In both cases read the README before beginning.

I have an internal Plug & Play modem and FreeBSD can't find it.

You will need to add the modem's PnP ID to the PnP ID list in the serial driver. To enable Plug & Play support, compile a new kernel with /sys/i386/isa/sio.c, at about line 1200. Look for the string "SUP1310" in the structure "siopnp_ids[]" to find the table. Build the kernel again, install, reboot, and your modem should be found.

You may have to manually configure the PnP devices using the `pnp' command in the boot-time configuration with a command like pnp 1 0 enable os irq0 3 drq0 0 port0 0x2f8 to make the modem show.

 How do I get the boot: prompt to show on the serial console?

Build a kernel with Create /boot.config and place Unplug the keyboard from the system.

See /usr/src/sys/i386/boot/biosboot/README.serial for information.

 Why doesn't my 3Com PCI network card work with my Micron computer?

Certain Micron motherboards have a non-conforming PCI BIOS implementation that does not configure PCI devices at the addresses reported. This causes grief when FreeBSD boots.

To work around this problem, disable the "Plug and Play Operating System" flag in the BIOS.

More information on this problem is available at URL: Does FreeBSD support Symmetric Multiproccessing (SMP)?

SMP is supported in 3.0-STABLE and later releases only. diff --git a/FAQ/misc.sgml b/FAQ/misc.sgml index 3b76b499c2..abe980b962 100644 --- a/FAQ/misc.sgml +++ b/FAQ/misc.sgml @@ -1,332 +1,332 @@ - + Miscellaneous Questions FreeBSD uses far more swap space than Linux. Why?

FreeBSD only appears to use more swap than Linux. In actual fact, it does not. The main difference between FreeBSD and Linux in this regard is that FreeBSD will proactively move entirely idle, unused pages of main memory into swap in order to make more main memory available for active use. Linux tends to only move pages to swap as a last resort. The perceived heavier use of swap is balanced by the more efficient use of main memory.

Note that while FreeBSD is proactive in this regard, it does not arbitrarily decide to swap pages when the system is truely idle. Thus you will not find your system all paged out when you get up in the morning after leaving it idle overnight. Why use (what are) a.out and ELF executable formats?

To understand why FreeBSD uses the a.out format, you must first know a little about the 3 currently "dominant" executable formats for UNIX:

The oldest and `classic' unix object format. It uses a short and compact header with a magic number at the beginning that's often used to characterize the format (see for more details). It contains three loaded segments: .text, .data, and .bss plus a symbol table and a string table. COFF

The SVR3 object format. The header now comprises a section table, so you can have more than just .text, .data, and .bss sections. ELF

The successor to FreeBSD tries to work around this problem somewhat by providing a utility for branding a known for more information.

FreeBSD comes from the "classic" camp and has traditionally used the format, a technology tried and proven through many generations of BSD releases. Though it has also been possible for some time to build and run native In FreeBSD's case, our shared library mechanism is based more closely on Sun's SunOS-style shared library mechanism and, as such, is very easy to use. However, starting with 3.0, FreeBSD officially supports Yes, but why are there so many different formats?

Back in the dim, dark past, there was simple hardware. This simple hardware supported a simple, small system. a.out was completely adequate for the job of representing binaries on this simple system (a PDP-11). As people ported unix from this simple system, they retained the a.out format because it was sufficient for the early ports of unix to architectures like the Motorola 68k, VAXen, etc.

Then some bright hardware engineer decided that if he could force software to do some sleazy tricks, then he'd be able to shave a few gates off the design and allow his CPU core to run faster. While it was made to work with this new kind of hardware (known these days as RISC), In addition, program sizes were getting huge and disks (and physical memory) were still relatively small so the concept of a shared library was born. The VM system also became more sophisticated. While each one of these advancements was done using the However, as time passed, the build tools that FreeBSD derived their build tools from (the assembler and loader especially) evolved in two parallel trees. The FreeBSD tree added shared libraries and fixed some bugs. The GNU folks that originally write these programs rewrote them and added simpler support for building cross compilers, plugging in different formats at will, etc. Since many people wanted to build cross compilers targeting FreeBSD, they were out of luck since the older sources that FreeBSD had for as and ld weren't up to the task. The new gnu tools chain (binutils) does support cross compiling, Why won't chmod change the permissions on symlinks?

You have to use either `` and man pages for more info.

without any options and follow the symlink with a trailing slash (``/''). For example, if `` chmod 555 foo/

With the trailing slash, will follow the symlink, `` Why are login names

You'd think it'd be easy enough to change In FreeBSD 3.0 and later, the maximum name length has been increased to 16 characters and those various utilities with hard-coded name sizes have been found and fixed. The fact that this touched so many areas of the system is why, in fact, the change was not made until 3.0.

If you're absolutely confident in your ability to find and fix these sorts of problems for yourself when and if they pop up, you can increase the login name length in earlier releases by editing /usr/include/utmp.h and changing UT_NAMESIZE accordingly. You must also update MAXLOGNAME in /usr/include/sys/param.h to match the UT_NAMESIZE change. Finally, if you build from sources, don't forget that /usr/include is updated each time! Change the appropriate files in /usr/src/.. instead.

Can I run DOS binaries under FreeBSD?

Yes, starting with version 3.0 you can using BSDI's if you're interested in joining this ongoing effort!

For pre-3.0 systems, there is a neat utility called in the ports collection which emulates an 8088 and enough BIOS services to run DOS text mode applications. It requires the X Window System (provided as XFree86). What is ``

stands for Software Update Protocol, and was developed by CMU for keeping their development trees in sync. We used it to keep remote sites in sync with our central development sources.

SUP is not bandwidth friendly, and has been retired. The current recommended method to keep your sources up to date is - + How cool is FreeBSD?

Q. Has anyone done any temperature testing while running FreeBSD? I know Linux runs cooler than dos, but have never seen a mention of FreeBSD. It seems to run really hot.

A. No, but we have done numerous taste tests on blindfolded volunteers who have also had 250 micrograms of LSD-25 administered beforehand. 35% of the volunteers said that FreeBSD tasted sort of orange, whereas Linux tasted like purple haze. Neither group mentioned any particular variances in temperature that I can remember. We eventually had to throw the results of this survey out entirely anyway when we found that too many volunteers were wandering out of the room during the tests, thus skewing the results. I think most of the volunteers are at Apple now, working on their new ``scratch and sniff'' GUI. It's a funny old business we're in!

Seriously, both FreeBSD and Linux use the `` Who's scratching in my memory banks??

Q. Is there anything "odd" that FreeBSD does when compiling the kernel which would cause the memory to make a scratchy sound? When compiling (and for a brief moment after recognizing the floppy drive upon startup, as well), a strange scratchy sound emanates from what appears to be the memory banks.

A. Yes! You'll see frequent references to ``daemons'' in the BSD documentation, and what most people don't know is that this refers to genuine, non-corporeal entities that now possess your computer. The scratchy sound coming from your memory is actually high-pitched whispering exchanged among the daemons as they best decide how to deal with various system administration tasks.

If the noise gets to you, a good ``fdisk /mbr'' from DOS will get rid of them, but don't be surprised if they react adversely and try to stop you. In fact, if at any point during the exercise you hear the satanic voice of Bill Gates coming from the built-in speaker, take off running and don't ever look back! Freed from the counterbalancing influence of the BSD daemons, the twin demons of DOS and Windows are often able to re-assert total control over your machine to the eternal damnation of your soul. Given a choice, I think I'd prefer to get used to the scratchy noises, myself! What does 'MFC' mean?

MFC is an acronym for 'Merged From -CURRENT.' It's used in the CVS logs to denote when a change was migrated from the CURRENT to the STABLE branches. What does 'BSD' mean?

It stands for something in a secret language that only members can know. It doesn't translate literally but its ok to tell you that BSD's translation is something between, 'Formula-1 Racing Team', 'Penguins are tasty snacks', and 'We have a better sense of humor than Linux.' :-)

Seriously, BSD is an acronym for 'Berkeley Software Distribution', which is the name the Berkeley CSRG (Computer Systems Research Group) chose for their Unix distribution way back when. diff --git a/FAQ/network.sgml b/FAQ/network.sgml index 329fb68188..870d714524 100644 --- a/FAQ/network.sgml +++ b/FAQ/network.sgml @@ -1,1258 +1,1258 @@ - + Networking Where can I get information on ``diskless booting''?

``Diskless booting'' means that the FreeBSD box is booted over a network, and reads the necessary files from a server instead of its hard disk. For full details, please read Can a FreeBSD box be used as a dedicated network router?

Internet standards and good engineering practice prohibit us from providing packet forwarding by default in FreeBSD. You can however enable this feature by changing the following variable to : gateway_enable=YES # Set to YES if this host will be a gateway

This option will put the variable In most cases, you will also need to run a routing process to tell other systems on your network about your router; FreeBSD comes with the standard BSD routing daemon , or for more complex situations you may want to try It is our duty to warn you that, even when FreeBSD is configured in this way, it does not completely comply with the Internet standard requirements for routers; however, it comes close enough for ordinary usage. Can I connect my Win95 box to the Internet via FreeBSD?

Typically, people who ask this question have two PC's at home, one with FreeBSD and one with Win95; the idea is to use the FreeBSD box to connect to the Internet and then be able to access the Internet from the Windows95 box through the FreeBSD box. This is really just a special case of the previous question.

There's a useful document available which explains how to set FreeBSD up as a

and on your FreeBSD box.

See also the section on . Why does recompiling the latest BIND from ISC fail?

There is a conflict between the ``compat/include/sys/cdefs.h. Does FreeBSD support SLIP and PPP?

Yes. See the man pages for , , and . deals exclusively with incoming connections and deals exclusively with outgoing connections.

These programs are described in the following sections of the : -

If you only have access to the Internet through a "shell account", you may want to have a look at the package. It can provide you with (limited) access to services such as ftp and http direct from your local machine. Does FreeBSD support NAT or Masquerading

If you have a local subnet (one or more local machines), but have been allocated only a single IP number from your Internet provider (or even if you receive a dynamic IP number), you may want to look at the program. The program has similar functionality built in via the is used in both cases. I can't make ppp work. What am I doing wrong ?

You should first read the and - the . Enable logging with the command set log Phase Chat Connect Carrier lcp ipcp ccp command

This command may be typed at the /etc/ppp/ppp.conf configuration file (the start of the default section is the best place to put it). Make sure that contains the lines !ppp *.* /var/log/ppp.log

and that the file /var/log/ppp.log exists. You can now find out a lot about what's going on from the log file. Don't worry if it doesn't all make sense. If you need to get help from someone, it may make sense to them.

If your version of ppp doesn't understand the "set log" command, you should download the . It will build on FreeBSD version 2.1.5 and higher. Ppp just hangs when I run it

This is usually because your hostname won't resolve. The best way to fix this is to make sure that /etc/hosts is consoluted by your resolver first by editing /etc/host.conf and putting the hosts line first. Then, simply put an entry in /etc/hosts for your local machine. If you have no local network, change your localhost line: 127.0.0.1 foo.bar.com foo localhost Otherwise, simply add another entry for your host. Consult the relevant man pages for more details.

You should be able to successfully ping -c1 `hostname` when you're done. Ppp won't dial in -auto mode

First, check that you've got a default route. By running name="netstat -rn">, you should see two entries like this: Destination Gateway Flags Refs Use Netif Expire default 10.0.0.2 UGSc 0 0 tun0 10.0.0.2 10.0.0.1 UH 0 0 tun0

This is assuming that you've used the addresses from the handbook, the man page or from the ppp.conf.sample file. If you haven't got a default route, it may be because you're running an old version of that doesn't understand the word add 0 0 HISADDR

line to one saying add 0 0 10.0.0.2

Another reason for the default route line being missing is that you have mistakenly set up a default router in your file (this file was called /etc/sysconfig prior to release 2.2.2), and you have omitted the line saying delete ALL

from ppp.conf. If this is the case, go back to the - section of the handbook. What does "No route to host" mean

This error is usually due to a missing MYADDR: delete ALL add 0 0 HISADDR

section in your /etc/ppp/ppp.linkup file. This is only necessary if you have a dynamic IP address or don't know the address of your gateway. If you're using interactive mode, you can type the following after entering delete ALL add 0 0 HISADDR -

Refer to the Refer to the section of the handbook for further details. My connection drops after about 3 minutes

The default ppp timeout is 3 minutes. This can be adjusted with the line set timeout NNN

where ppp.conf file, or to type it at the prompt in interactive mode. It is also possible to adjust it on the fly while the line is active by connecting to or . Refer to the man page for further details. My connection drops under heavy load

If you have Link Quality Reporting (LQR) configured, it is possible that too many LQR packets are lost between your machine and the peer. Ppp deduces that the line must therefore be bad, and disconnects. Prior to FreeBSD version 2.2.5, LQR was enabled by default. It is now disabled by default. LQR can be disabled with the line disable lqr My connection drops after a random amount of time

Sometimes, on a noisy phone line or even on a line with call waiting enabled, your modem may hang up because it thinks (incorrectly) that it lost carrier.

There's a setting on most modems for determining how tolerant it should be to temporary losses of carrier. On a USR Sportster for example, this is measured by the S10 register in tenths of a second. To make your modem more forgiving, you could add the following send-expect sequence to your dial string: set dial "...... ATS10=10 OK ......"

Refer to your modem manual for details. My connection hangs after a random amount of time

Many people experience hung connections with no apparent explaination. The first thing to establish is which side of the link is hung.

If you are using an external modem, you can simply try using Having established whether the problem is local or remote, you now have to possibilities: The remote end isn't responding

There's very little you can do about this. Most ISPs will refuse to help if you're not running a Microsoft OS. You can First, try disabling all local compression by adding the following to your configuration: disable pred1 deflate deflate24 protocomp acfcomp shortseq vj deny pred1 deflate deflate24 protocomp acfcomp shortseq vj

Then reconnect to ensure that this makes no difference. If things improve or if the problem is solved completely, determine which setting makes the difference through trial and error. This will provide good amunition when you contact your ISP (although it may make it apparent that you're not running a Microsoft product).

Before contacting your ISP, enable async logging locally and wait until the connection hangs again. This may use up quite a bit of disk space. The last data read from the port may be of interest. It is usually ascii data, and may even describe the problem (``Memory fault, core dumped'' ?).

If your ISP is helpful, they should be able to enable logging on their end, then when the next link drop occurs, they may be able to tell you why their side is having a problem. Feel free to send the details to , or even to ask your ISP to contact me directly. Ppp is hung

Your best bet here is to rebuild ppp by adding Send the results to . Nothing happens after the Login OK! message

Prior to FreeBSD version 2.2.5, once the link was established, would wait for the peer to initiate the Line Control Protocol (LCP). Many ISPs will not initiate negotiations and expect the client to do so. To force set openmode active

I keep seeing errors about magic being the same

Occasionally, just after connecting, you may see messages in the log that say "magic is the same". Sometimes, these messages are harmless, and sometimes one side or the other exits. Most ppp implementations cannot survive this problem, and even if the link seems to come up, you'll see repeated configure requests and configure acknowledgements in the log file until ppp eventually gives up and closes the connection.

This normally happens on server machines with slow disks that are spawning a getty on the port, and executing ppp from a login script or program after login. I've also heard reports of it happening consistently when using slirp. The reason is that in the time taken between getty exiting and ppp starting, the client-side ppp starts sending Line Control Protocol (LCP) packets. Because ECHO is still switched on for the port on the server, the client ppp sees these packets "reflect" back.

One part of the LCP negotiation is to establish a magic number for each side of the link so that "reflections" can be detected. The protocol says that when the peer tries to negotiate the same magic number, a NAK should be sent and a new magic number should be chosen. During the period that the server port has ECHO turned on, the client ppp sends LCP packets, sees the same magic in the reflected packet and NAKs it. It also sees the NAK reflect (which also means ppp must change its magic). This produces a potentially enormous number of magic number changes, all of which are happily piling into the server's tty buffer. As soon as ppp starts on the server, it's flooded with magic number changes and almost immediately decides it's tried enough to negotiate LCP and gives up. Meanwhile, the client, who no longer sees the reflections, becomes happy just in time to see a hangup from the server.

This can be avoided by allowing the peer to start negotiating with the following line in your ppp.conf file: set openmode passive

This tells ppp to wait for the server to initiate LCP negotiations. Some servers however may never initiate negotiations. If this is the case, you can do something like: set openmode active 3

This tells ppp to be passive for 3 seconds, and then to start sending LCP requests. If the peer starts sending requests during this period, ppp will immediately respond rather than waiting for the full 3 second period. LCP negotiations continue 'till the connection is closed

There is currently an implementation mis-feature in This goes on 'till one side figures out that they're getting nowhere and gives up.

The best way to avoid this is to configure one side to be set openmode passive command. Care should be taken with this option. You should also use the set stopped N command to limit the amount of time that set openmode active N command (where Ppp locks up shortly after connecting

Prior to version 2.2.5 of FreeBSD, it was possible that your link was disabled shortly after connection due to disable pred1 Ppp locks up when I shell out to test it

When you execute the If you wish to execute commands like this, use the Ppp over a null-modem cable never exits

There is no way for enable lqr

LQR is accepted by default if negotiated by the peer. Why does ppp dial for no reason in -auto mode

If To determine the cause, use the following line: set log +tcp/ip

This will log all traffic through the connection. The next time the line comes up unexpectedly, you will see the reason logged with a convenient timestamp next to it.

You can now disable dialing under these circumstances. Usually, this sort of problem arises due to DNS lookups. To prevent DNS lookups from establishing a connection (this will set dfilter 1 deny udp src eq 53 set dfilter 2 deny udp dst eq 53 set dfilter 3 permit 0/0 0/0

This is not always suitable, as it will effectively break your demand-dial capabilities - most programs will need a DNS lookup before doing any other network related things.

In the DNS case, you should try to determine what is actually trying to resolve a host name. A lot of the time, is the culprit. You should make sure that you tell sendmail not to do any DNS lookups in its configuration file. See the section on for details on how to create your own configuration file and what should go into it. You may also want to add the following line to your define(`confDELIVERY_MODE', `d')dnl

This will make sendmail queue everything until the queue is run (usually, sendmail is invoked with ``-bd -q30m'', telling it to run the queue every 30 minutes) or until a ``sendmail -q'' is done (perhaps from your ppp.linkup file). What do these CCP errors mean

I keep seeing the following errors in my log file: CCP: CcpSendConfigReq CCP: Received Terminate Ack (1) state = Req-Sent (6)

This is because ppp is trying to negotiate Predictor1 compression, and the peer does not want to negotiate any compression at all. The messages are harmless, but if you wish to remove them, you can disable Predictor1 compression locally too: disable pred1 Ppp locks up during file transfers with IO errors

Under FreeBSD 2.2.2 and before, there was a bug in the tun driver that prevents incoming packets of a size larger than the tun interface's MTU size. Receipt of a packet greater than the MTU size results in an IO error being logged via syslogd.

The ppp specification says that an MRU of 1500 should always be accepted as a minimum, despite any LCP negotiations, therefore it is possible that should you decrease the MTU to less than 1500, your ISP will transmit packets of 1500 regardless, and you will tickle this non-feature - locking up your link.

The problem can be circumvented by never setting an MTU of less than 1500 under FreeBSD 2.2.2 or before. Why doesn't ppp log my connection speed?

In order to log all lines of your modem ``conversation'', you must enable the following: set log +connect

This will make log everything up until the last requested "expect" string.

If you wish to see your connect speed and are using PAP or CHAP (and therefore don't have anything to "chat" after the CONNECT in the dial script - no "set login" script), you must make sure that you instruct ppp to "expect" the whole CONNECT line, something like this: set dial "ABORT BUSY ABORT NO\\sCARRIER TIMEOUT 4 \"\" ATZ OK-ATZ-OK ATDT\\T TIMEOUT 60 CONNECT \\c \\n"

Here, we get our CONNECT, send nothing, then expect a line-feed, forcing Ppp ignores the `\' character in my chat script

Ppp parses each line in your config files so that it can interpret strings such as When the chat interpreter parses each argument, it re-interprets the argument in order to find any special escape sequences such as ``\P'' or ``\T'' (see the man page). As a result of this double-parsing, you must remember to use the correct number of escapes.

If you wish to actually send a ``\'' character to (say) your modem, you'd need something like: set dial "\"\" ATZ OK-ATZ-OK AT\\\\X OK"

resulting in the following sequence: ATZ OK AT\X OK

or set phone 1234567 set dial "\"\" ATZ OK ATDT\\T"

resulting in the following sequence: ATZ OK ATDT1234567 Ppp gets a seg-fault, but I see no

Ppp (or any other program for that matter) should never dump core. Because ppp runs with an effective user id of 0, the operating system will not write ppps core image to disk before terminating it. If, however ppp $ tar xfz ppp-*.src.tar.gz $ cd ppp*/ppp $ echo STRIP= >>Makefile $ echo CFLAGS+=-g >>Makefile $ make clean all $ su # make install # chmod 555 /usr/sbin/ppp

You will now have a debuggable version of ppp installed. You will have to be root to run ppp as all of its privileges have been revoked. When you start ppp, take a careful note of what your current directory was at the time.

Now, if and when ppp receives the segmentation violation, it will dump a core file called ppp.core. You should then do the following: $ su # gdb /usr/sbin/ppp ppp.core (gdb) bt ..... (gdb) f 0 ..... (gdb) i args ..... (gdb) l .....

All of this information should be given alongside your question, making it possible to diagnose the problem.

If you're familiar with gdb, you may wish to find out some other bits and pieces such as what actually caused the dump and the addresses & values of the relevant variables. The process that forces a dial in auto mode never connects

This was a known problem with The problem was that when that initial program calls , the IP number of the tun interface is assigned to the socket endpoint. The kernel creates the first outgoing packet and writes it to the tun device. There are several theoretical ways to approach this problem. It would be nicest if the peer would re-assign the same IP number if possible The easiest method from our side would be to never change the tun interface IP number, but instead to change all outgoing packets so that the source IP number is changed from the interface IP to the negotiated IP on the fly. This is essentially what the and ppp's Another alternative (and probably the most reliable) would be to implement a system call that changes all bound sockets from one IP to another. Yet another possibility is to allow an interface to be brought up without an IP number. Outgoing packets would be given an IP number of 255.255.255.255 up until the first SIOCAIFADDR ioctl is done. This would result in fully binding the socket. It would be up to Why don't most games work with the -alias switch

The reason games and the like don't work when libalias is in use is that the machine on the outside will try to open a connection or send (unsolicited) UDP packets to the machine on the inside. The packet alias software doesn't know that it should send these packets to the interior machine.

To make things work, make sure that the only thing running is the software that you're having problems with, then either run tcpdump on the tun interface of the gateway or enable ppp tcp/ip logging (``set log +tcp/ip'') on the gateway.

When you start the offending software, you should see packets passing through the gateway machine. When something comes back from the outside, it'll be dropped (that's the problem). Note the port number of these packets then shut down the offending software. Do this a few times to see if the port numbers are consistent. If they are, then the following line in the relevant section of /etc/ppp/ppp.conf will make the software functional: alias port proto internalmachine:port port

where ``proto'' is either ``tcp'' or ``udp'', ``internalmachine'' is the machine that you want the packets to be sent to and ``port'' is the destination port number of the packets.

You won't be able to use the software on other machines without changing the above command, and running the software on two internal machines at the same time is out of the question - after all, the outside world is seeing your entire internal network as being just a single machine.

If the port numbers aren't consistent, there are three more options:

1) Submit support in libalias. Examples of ``special cases'' can be found in /usr/src/lib/libalias/alias_*.c (alias_ftp.c is a good prototype). This usually involves reading certain recognised outgoing packets, identifying the instruction that tells the outside machine to initiate a connection back to the internal machine on a specific (random) port and setting up a ``route'' in the alias table so that the subsequent packets know where to go.

This is the most difficult solution, but it is the best and will make the software work with multiple machines.

2) Use a proxy. The application may support socks5 for example, or (as in the ``cvsup'' case) may have a ``passive'' option that avoids ever requesting that the peer open connections back to the local machine.

3) Redirect everything to the internal machine using ``alias addr''. This is the sledge-hammer approach. What are FCS errors ?

FCS stands for show hdlc command.

If your link is bad (or if your serial driver is dropping packets), you will see the occasional FCS error. This is not usually worth worrying about although it does slow down the compression protocols substantially. If you have an external modem, make sure your cable is properly shielded from interference - this may eradicate the problem.

If your link freezes as soon as you've connected and you see a large number of FCS errors, this may be because your link is not 8 bit clean. Make sure your modem is not using software flow control (XON/XOFF). If your datalink must use software flow control, use the command set accmap 0x000a0000 to tell ppp to escape the ^Q and ^S characters.

Another reason for seeing too many FCS errors may be that the remote end has stopped talking close lcp command (a following term command will reconnect you to the shell on the remote machine.

If nothing in your log file indicates why the link might have been terminated, you should ask the remote administrator (your ISP?) why the session was terminated. None of this helps - I'm desperate !

If all else fails, send as much information as you can, including your config files, how you're starting command (before and after connecting) to the mailing list or the news group, and someone should point you in the right direction. I can't create a /dev/ed0 device!

In the Berkeley networking framework, network interfaces are only directly accessible by kernel code. Please see the /etc/rc.network file and the manual pages for the various network programs mentioned there for more information. If this leaves you totally confused, then you should pick up a book describing network administration on another BSD-related operating system; with few significant exceptions, administering networking on FreeBSD is basically the same as on SunOS 4.0 or Ultrix. How can I setup Ethernet aliases?

Add `` command-line like the following: ifconfig ed0 alias 204.141.95.2 netmask 0xffffffff How do I get my 3C503 to use the other network port?

If you want to use the other ports, you'll have to specify an additional parameter on the command line. The default port is ``. I'm having problems with NFS to/from FreeBSD.

Certain PC network cards are better than others (to put it mildly) and can sometimes cause problems with network intensive applications like NFS.

See for more information on this topic. Why can't I NFS-mount from a Linux box?

Some versions of the Linux NFS code only accept mount requests from a privileged port; try mount -o -P linuxbox:/blah /mnt Why can't I NFS-mount from a Sun box?

Sun workstations running SunOS 4.X only accept mount requests from a privileged port; try mount -o -P sunbox:/blah /mnt I'm having problems talking PPP to NeXTStep machines.

Try disabling the TCP extensions in by changing the following variable to NO: tcp_extensions=NO

Xylogic's Annex boxes are also broken in this regard and you must use the above change to connect thru them. How do I enable IP multicast support?

Multicast host operations are fully supported in FreeBSD 2.0 and later by default. If you want your box to run as a multicast router, you will need to recompile your kernel with the MROUTING option and run /etc/rc.conf.

MBONE tools are available in their own ports category, mbone. If you are looking for the conference tools For more information, see the . Which network cards are based on the DEC PCI chipset?

Here is a list compiled by , with some more modern additions: Vendor Model ---------------------------------------------- ASUS PCI-L101-TB Accton ENI1203 Cogent EM960PCI Compex ENET32-PCI D-Link DE-530 Dayna DP1203, DP2100 DEC DE435 Danpex EN-9400P3 JCIS Condor JC1260 Linksys EtherPCI Mylex LNP101 SMC EtherPower 10/100 (Model 9332) SMC EtherPower (Model 8432) TopWare TE-3500P Zynx ZX342 Why do I have to use the FQDN for hosts on my site?

You will probably find that the host is actually in a different domain; for example, if you are in foo.bar.edu and you wish to reach a host called ``mumble'' in the bar.edu domain, you will have to refer to it by the fully-qualified domain name, ``mumble.bar.edu'', instead of just ``mumble''.

Traditionally, this was allowed by BSD BIND resolvers. However the current version of that ships with FreeBSD no longer provides default abbreviations for non-fully qualified domain names other than the domain you are in. So an unqualified host mumble must either be found as mumble.foo.bar.edu, or it will be searched for in the root domain.

This is different from the previous behavior, where the search continued across mumble.bar.edu, and mumble.edu. Have a look at RFC 1535 for why this was considered bad practice, or even a security hole.

As a good workaround, you can place the line search foo.bar.edu bar.edu

instead of the previous domain foo.bar.edu

into your file. However, make sure that the search order does not go beyond the ``boundary between local and public administration'', as RFC 1535 calls it. ``Permission denied'' for all networking operations.

If you have compiled your kernel with the If you had unintentionally misconfigured your system for firewalling, you can restore network operability by typing the following while logged in as root: ipfw add 65534 allow all from any to any

You can also set "firewall_type='open'" in /etc/rc.conf.

For further information on configuring a FreeBSD firewall, see the . How much overhead does IPFW incur?

The answer to this depends mostly on your rule set and processor speed. For most applications dealing with ethernet and small rule sets, the answer is, negligible. For those of you that need actual measurements to satisfy your curiosity, read on.

The following measurements were made using 2.2.5-STABLE on a 486-66. IPFW was modified to measure the time spent within the Two rule sets, each with 1000 rules were tested. The first set was designed to demonstrate a worst case scenario by repeating the rule: ipfw add deny tcp from any to any 55555

This demonstrates worst case by causing most of IPFW's packet check routine to be executed before finally deciding that the packet does not match the rule (by virtue of the port number). Following the 999th iteration of this rule was an allow ip from any to any.

The second set of rules were designed to abort the rule check quickly: ipfw add deny ip from 1.2.3.4 to 1.2.3.4

The nonmatching source IP address for the above rule causes these rules to be skipped very quickly. As before, the 1000th rule was an allow ip from any to any.

The per-packet processing overhead in the former case was approximately 2.703ms/packet, or roughly 2.7 microseconds per rule. Thus the theoretical packet processing limit with these rules is around 370 packets per second. Assuming 10Mbps ethernet and a ~1500 byte packet size, we would only be able to achieve a 55.5% bandwidth utilization.

For the latter case each packet was processed in approximately 1.172ms, or roughly 1.2 microseconds per rule. The theoretical packet processing limit here would be about 853 packets per second, which could consume 10Mbps ethernet bandwidth.

The excessive number of rules tested and the nature of those rules do not provide a real-world scenario -- they were used only to generate the timing information presented here. Here are a few things to keep in mind when building an efficient rule set: Place an `established' rule early on to handle the majority of TCP traffic. Don't put any allow tcp statements before this rule. Place heavily triggered rules earlier in the rule set than those rarely used (without changing the permissiveness of the firewall, of course). You can see which rules are used most often by examining the packet counting statistics with ipfw -a l. How can I redirect service requests from one machine to another?

You can redirect FTP (and other service) request with the 'socket' package, available in the ports tree in category 'sysutils'. Simply replace the service's commandline to call socket instead, like so: ftp stream tcp nowait nobody /usr/local/bin/socket socket ftp.foo.com ftp

where 'ftp.foo.com' and 'ftp' are the host and port to redirect to, respectively. Where can I get a bandwidth management tool?

There are two bandwidth management tools available for FreeBSD. is available for free; Bandwidth Manager from is a commercial product. Why do I get ``/dev/bpf0: device not configured"?

The Berkeley Packet Filter driver needs to be enabled before running programs that utilize it. Add this to your kernel config file and build a new kernel: pseudo-device bpfilter # Berkeley Packet Filter

Secondly, after rebooting you will have to create the device node. This can be accomplished by a change to the /dev directory, followed by the execution of: # sh MAKEDEV bpf0 -

Please see the Please see the for more information on creating devices. diff --git a/FAQ/preface.sgml b/FAQ/preface.sgml index 65625cb288..f9a1b6d4fd 100644 --- a/FAQ/preface.sgml +++ b/FAQ/preface.sgml @@ -1,608 +1,608 @@ - + Preface

Welcome to the FreeBSD 2.X FAQ! What is the purpose of this FAQ?

As is usual with Usenet FAQs, this document aims to cover the most frequently asked questions concerning the FreeBSD operating system (and of course answer them!). Although originally intended to reduce bandwidth and avoid the same old questions being asked over and over again, FAQs have become recognized as valuable information resources.

Every effort has been made to make this FAQ as informative as possible; if you have any suggestions as to how it may be improved, please feel free to mail them to the . What is FreeBSD?

Briefly, FreeBSD 2.X is a UN*X-like operating system based on U.C. Berkeley's 4.4BSD-lite release for the i386 platform. It is also based indirectly on William Jolitz's port of U.C. Berkeley's Net/2 to the i386, known as 386BSD, though very little of the 386BSD code remains. A fuller description of what FreeBSD is and how it can work for you may be found on the .

FreeBSD is used by companies, Internet Service Providers, researchers, computer professionals, students and home users all over the world in their work, education and recreation. See some of them in the

For more detailed information on FreeBSD, please see the What are the goals of FreeBSD?

The goals of the FreeBSD Project are to provide software that may be used for any purpose and without strings attached. Many of us have a significant investment in the code (and project) and would certainly not mind a little financial compensation now and then, but we're definitely not prepared to insist on it. We believe that our first and foremost "mission" is to provide code to any and all comers, and for whatever purpose, so that the code gets the widest possible use and provides the widest possible benefit. This is, we believe, one of the most fundamental goals of Free Software and one that we enthusiastically support.

That code in our source tree which falls under the GNU Public License (GPL) or GNU Library Public License (GLPL) comes with slightly more strings attached, though at least on the side of enforced access rather than the usual opposite. Due to the additional complexities that can evolve in the commercial use of GPL software, we do, however, endeavor to replace such software with submissions under the more relaxed BSD copyright whenever possible. Why is it called FreeBSD?

It may be used free of charge, even by commercial users. Full source for the operating system is freely available, and the minimum possible restrictions have been placed upon its use, distribution and incorporation into other work (commercial or non-commercial). Anyone who has an improvement and/or bug fix is free to submit their code and have it added to the source tree (subject to one or two obvious provisos).

For those of our readers whose first language is not English, it may be worth pointing out that the word ``free'' is being used in two ways here, one meaning ``at no cost'', the other meaning ``you can do whatever you like''. Apart from one or two things you What is the latest version of FreeBSD?

Version is the latest Briefly explained, What is FreeBSD-current? -

is the +

is the development version of the operating system, which will in due course become 4.0-RELEASE. As such, it is really only of interest to developers working on the system and die-hard hobbyists. - See the + See the in the for details on running -current.

If you are not familiar with the operating system or are not capable of identifying the difference between a real problem and a temporary problem, you should not use FreeBSD-current. This branch sometimes evolves quite quickly and can be un-buildable for a number of days at a time. People that use FreeBSD-current are expected to be able to analyze any problems and only report them if they are deemed to be mistakes rather than ``glitches''. Questions such as ``make world produces some error about groups'' on the -current mailing list are sometimes treated with contempt.

Every now and again, a release is also made of this -current development code, CDROM distributions of the occasional snapshot even now being made available. The goals behind each snapshot release are: To test the latest version of the installation software. To give people who would like to run -current but who don't have the time and/or bandwidth to follow it on a day-to-day basis an easy way of bootstrapping it onto their systems. To preserve a fixed reference point for the code in question, just in case we break something really badly later. (Although CVS normally prevents anything horrible like this happening :) To ensure that any new features in need of testing have the greatest possible number of potential testers.

No claims are made that any snapshot can be considered ``production quality'' for any purpose. For stability and tested mettle, you will have to stick to full releases.

Snapshot releases are directly available from and are generated, on the average, once a day for both the 4.0-current and 3.0-stable branches. What is the FreeBSD-stable concept?

Back when FreeBSD 2.0.5 was released, we decided to branch FreeBSD development into two parts. One branch was named , with the intention that only well-tested bug fixes and small incremental enhancements would be made to it (for Internet Service Providers and other commercial enterprises for whom sudden shifts or experimental features are quite undesirable). The other branch was - , which + , which essentially has been one unbroken line leading towards 4.0-RELEASE (and beyond) since 2.0 was released. If a little ASCII art would help, this is how it looks: 2.0 | | | [2.1-stable] *BRANCH* 2.0.5 -> 2.1 -> 2.1.5 -> 2.1.6 -> 2.1.7.1 [2.1-stable ends] | (Mar 1997) | | | [2.2-stable] *BRANCH* 2.2.1 -> 2.2.2-RELEASE -> 2.2.5 -> 2.2.6 -> 2.2.7 -> 2.2.8 [end] | (Mar 1997) (Oct 97) (Apr 98) (Jul 98) (Dec 98) | | 3.0-SNAPs (started Q1 1997) | | 3.0.0-RELEASE (Oct 1998) | | [3.0-stable] *BRANCH* 3.1 (Feb 1999) -> ... future 3.x releases ... | | \|/ + [4.0-current continues]

The -current branch is slowly progressing towards 4.0 and beyond, the previous 2.2-stable branch having just retired with the release of 2.2.8. 3.0-stable has now replaced it, the next release coming up with 3.1 in early 1999. 4.0-current is now the "current branch", with the first 4.0 releases appearing in Q1 2000. When are FreeBSD releases made?

As a general principle, the FreeBSD core team only release a new version of FreeBSD when they believe that there are sufficient new features and/or bug fixes to justify one, and are satisfied that the changes made have settled down sufficiently to avoid compromising the stability of the release. Many users regard this caution as one of the best things about FreeBSD, although it can be a little frustrating when waiting for all the latest goodies to become available...

Releases are made about every 4 months on average.

For people needing (or wanting) a little more excitement, there are SNAPs released more frequently, particularly during the month or so leading up to a release. Is FreeBSD only available for PCs ?

FreeBSD 3.x currently runs on the as well as the x86 architecture. Some interest has also been expressed in a SPARC port, but details on this project are not yet clear. If your machine has a different architecture and you need something right now, we suggest you look at or . Who is responsible for FreeBSD?

The key decisions concerning the FreeBSD project, such as the overall direction of the project and who is allowed to add code to - the source tree, are made by a of some 15 people. There is a much larger team of - over 100 who are authorized to make changes directly to the FreeBSD source tree.

However, most non-trivial changes are discussed in advance in the , and there are no restrictions on who may take part in the discussion. Where can I get FreeBSD?

Every significant release of FreeBSD is available via anonymous ftp from the : For the current 2.2-stable release, 2.2.8R, see the directory. For the current 3.0-stable release, 3.0-RELEASE, see the directory. releases are made once a day along the RELENG_2_2 branch (post 2.2.8) as it slowly winds down in maintenance mode. The RELENG_2_2 branch is currently being carefully maintained by the legacy support folks and no changes other than those strictly necessary for security or reliability enhancements are now made. releases are also made once a day along the RELENG_3 branch (post 3.0-release) as it continues on its way towards 3.1-RELEASE. releases are made once a day for the branch, these being of service purely to bleeding-edge testers and developers.

FreeBSD is also available via CDROM, from the following place(s):

Walnut Creek CDROM 4041 Pike Lane, Suite F Concord, CA 94520 USA Orders: +1 800 786-9907 Questions: +1 925 674-0783 FAX: +1 925 674-0821 email: WWW:

In Australia, you may find it at:

Advanced Multimedia Distributors Factory 1/1 Ovata Drive Tullamarine, Melbourne Victoria Australia Voice: +61 3 9338 6777 CDROM Support BBS 17 Irvine St Peppermint Grove WA 6011 Voice: +61 9 385-3793 Fax: +61 9 385-2360 And in the UK: The Public Domain & Shareware Library Winscombe House, Beacon Rd Crowborough Sussex. TN6 1UL Voice: +44 1892 663-298 Fax: +44 1892 667-473 Where do I find info on the FreeBSD mailing lists?

You can find full information in the What FreeBSD news groups are available?

You can find full information in the Are there FreeBSD IRC (Internet Relay Chat) channels?

Yes, most major IRC networks host a FreeBSD chat channel: Channel #FreeBSD on EFNet is a FreeBSD forum, but don't go there for tech support or to try and get folks there to help you avoid the pain of reading man pages or doing your own research. It is a chat channel, first and foremost, and topics there are just as likely to involve sex, sports or nuclear weapons as they are FreeBSD. You Have Been Warned! Available at server irc.chat.org. Channel #FreeBSD on DALNET is available at irc.dal.net in the US and irc.eu.dal.net in Europe. Channel #FreeBSD on UNDERNET is available at us.undernet.org in the US and eu.undernet.org in Europe. Same provisions as for EFNET apply - either don't ask questions or learn to ask amazingly politely if you want help. It's a chat channel, not a help channel. Finally, you can also join #FreeBSD on BSDNET, a smaller BSD only chat network, at irc.FreeBSD.org. This network attempts to do more tech support and not be as anarchistic as EFNET, UNDERNET or DALNET, but it's also nowhere near as popular as a result. Why not volunteer to answer FreeBSD questions on BSDNET today?

Each of these channels are distinct and are not connected to each other. Their chat styles also differ, so you may need to try each to find one suited to your chat style. As with *all* types of IRC traffic, if you're easily offended or can't deal with lots of young people (and more than a few older ones) doing the verbal equivalent of jello wrestling, don't even bother with it. Books on FreeBSD

There is a FreeBSD Documentation Project which you may contact (or even better, join) on the doc mailing list: . This list is for discussion of the FreeBSD documentation. For actual questions about FreeBSD, there is the questions mailing list: .

A FreeBSD ``handbook'' is available, and can be found as: . Note that this is a work in progress, and so parts may be incomplete.

The definitive printed guide on FreeBSD is ``The Complete FreeBSD'', written by Greg Lehey and published by Walnut Creek CDROM Books. Now in its second edition, the book contains 1,750 pages of install & system administration guidance, program setup help, and manual pages. The book (and current FreeBSD release) can be ordered from , , or at your favorite bookstore. The ISBN is 1-57176-227-2.

However, as FreeBSD 2.2.X is based upon Berkeley 4.4BSD-Lite2, most of the 4.4BSD manuals are applicable to FreeBSD 2.2.X. O'Reilly and Associates publishes these manuals: 4.4BSD System Manager's Manual By Computer Systems Research Group, UC Berkeley 1st Edition June 1994, 804 pages : 1-56592-080-5 4.4BSD User's Reference Manual By Computer Systems Research Group, UC Berkeley 1st Edition June 1994, 905 pages : 1-56592-075-9 4.4BSD User's Supplementary Documents By Computer Systems Research Group, UC Berkeley 1st Edition July 1994, 712 pages : 1-56592-076-7 4.4BSD Programmer's Reference Manual By Computer Systems Research Group, UC Berkeley 1st Edition June 1994, 886 pages : 1-56592-078-3 4.4BSD Programmer's Supplementary Documents By Computer Systems Research Group, UC Berkeley 1st Edition July 1994, 596 pages : 1-56592-079-1

A description of these can be found via WWW as: . Due to poor sales, however, these manuals may be hard to get a hold of.

For a more in-depth look at the 4.4BSD kernel organization, you can't go wrong with:

McKusick, Marshall Kirk, Keith Bostic, Michael J Karels, and John Quarterman.

The Design and Implementation of the 4.4BSD Operating System. Reading, Mass. : Addison-Wesley, 1996. 0-201-54979-4

A good book on system administration is:

Evi Nemeth, Garth Snyder, Scott Seebass & Trent R. Hein, ``Unix System Administration Handbook'', Prentice-Hall, 1995 : 0-13-151051-7

This book covers the basics, as well as TCP/IP, DNS, NFS, SLIP/PPP, sendmail, INN/NNTP, printing, etc.. It's expensive (approx. US$45-$55), but worth it. It also includes a CDROM with the sources for various tools; most of these, however, are also on the FreeBSD 2.2.6R CDROM (and the FreeBSD CDROM often has newer versions). How do I access your Problem Report database?

The Problem Report database of all open user change requests may be queried (or submitted to) by using our web-based PR and interfaces. The send-pr(1) command can also be used to submit problem reports and change requests via electronic mail. Where can I get ASCII/PostScript versions of the FAQ?

The up-to-date FAQ is available from the FreeBSD Web Server or any mirror as PostScript and plain text (7 bit ASCII and 8-bit Latin1).

As PostScript (about 370KB):

As ASCII text (about 220KB):

As ISO 8859-1 text (about 220KB): Where can I get ASCII/PostScript versions of the Handbook?

The up-to-date Handbook is available from the FreeBSD Web Server or any mirror as PostScript and plain text (7 bit ASCII and 8-bit Latin1).

As PostScript (about 1.7MB):

As ASCII text (about 1080KB):

As ISO 8859-1 text (about 1080KB): The ASCII handbook isn't plain text!

True, the ASCII and Latin1 versions of the FAQ and Handbook aren't strictly plaintext; they contain underlines and overprints that assume the output is going directly to a dot matrix printer. If you need to reformat them to be human-readable, run the file through col: $ col -b < inputfile > outputfile I'd like to become a FreeBSD Web mirror!

Certainly! There are multiple ways to mirror the Web pages. Using CVSUP: You can retrieve the formatted files using CVSUP from cvsup.freebsd.org. Add this line to your cvsup file: www release=current hostname=/home base=/usr/local/etc/cvsup prefix=/usr/local/www/data/www.freebsd.org delete old use-rel-suffix Using rsync: See for information. Using ftp mirror: You can download the FTP server's copy of the web site using your favorite ftp mirror tool. Simply start at ftp://ftp.freebsd.org/pub/FreeBSD/FreeBSD-current/www. I'd like to translate the documentation into Friesian.

Well, we can't pay, but we might arrange a free CD or T-shirt and a Contributor's Handbook entry if you submit a translation of the documentation. Other sources of information.

The following newsgroups contain pertinent discussion for FreeBSD users: (moderated)

Web resources: The .

The FreeBSD handbook also has a fairly complete section which is worth reading if you're looking for actual books to buy.