# ifplugd 0.28

Copyright 2002-2005 Lennart Poettering <mzvscyhtq (at) 0pointer (dot) de>

## License

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

## News

Sat Jun 4 2005:

Version 0.28 released, changes include: build fixes from Stefan Seyfried.

Wed Mar 30 2005:

Version 0.27 released, changes include: new option `--no-startup`.

Sun Dec 19 2004:

Version 0.26 released, changes include: changed MII code for better compatibility with some 3COM Boomerang cards.

Mon May 10 2004:

Version 0.25 released, changes include: Revert to more classic link checking support. The new checking order is: ETHTOOL, MII, WLAN, IFF. The obsolete API "PRIV" is no longer checked by the automatic API detection code. However, you may enable it forcibly by passing `-m priv` on the command line.

Mon Apr 12 2004:

Version 0.24 released, changes include: add `IFF_RUNNING` link check support and make it the default. This might break some setups. You may workaround this by passing `-m` to the daemon for selecting a different API. Please report breakages!

Wed Apr 7 2004:

Version 0.23 released, changes include: don't make `/dev/tty1` the controlling TTY when beeping

Tue Feb 10 2004:

Version 0.22 released, changes include: rename `ifstatus` to `ifplugstatus` due to namespace collision, minor fixes

Mon Jan 26 2004:

Version 0.21b released, added missing file.

Mon Jan 26 2004:

Version 0.21 released, changes include: better compatibility with wireless devices, compatibility with newer kernels

Sun Nov 9 2003:

Version 0.20 released, changes include: fix wrong message, build fix

Mon Oct 20 2003:

Version 0.19 released, changes include: New option `--wait-for-kill`, this requires `libdaemon 0.3`

Fri Oct 17 2003:

Version 0.18 released, changes include: Some bugs fixed

Fri Sep 13 2003:

Version 0.17b released, changes include: typo and date fix

Fri Sep 13 2003:

Version 0.17 released, changes include: documentation update, better support for multiple interfaces, gcc 2.95 build fix

Thu Aug 13 2003:

Version 0.16 released, changes include: RPM spec file added, build fixes, WLAN improvements (including compatibility with the upcoming `waproamd`, a WLAN roaming daemon), monitor mode for use in conjunction with PCMCIA devices, better support for multiple interface setups, `SUPPORTED_DRIVERS` returns

Thu July 10 2003:

Version 0.15 released, changes include: bad umask fix, documentation update

Mon July 7 2003:

Version 0.14 released, changes include: autoconf usage, new dependency `libdaemon`, wireless LAN support, support for suspending/resuming, many fixes

## Overview

`ifplugd` is a Linux daemon which will automatically configure your ethernet device when a cable is plugged in and automatically unconfigure it if the cable is pulled. This is useful on laptops with onboard network adapters, since it will only configure the interface when a cable is really connected.

`ifplugd` ifplugd interfaces with your distribution's native network configuration utilities.

Some features:

- Uses your distribution's native `ifup`/`ifdown` programs.
- May beep when the cable is unplugged, plugged, the interface configuration succeeded or failed.
- Supports the Linux `SIOCETHTOOL` (newer, aka `ethtool` API), `SIOCGMIIREG` (older, aka `mii-diag`/`mii-tool` API) and SIOCDEVPRIVATE (oldest, aka `mii-tool` API) `ioctl()`s for getting link status. Release 0.24 introduces support for link detection with the `IFF_RUNNING` interface flag.
- Syslog support
- Small program - the binary is just 25 KB (plus 16 KB for `libdaemon`).
- Multiple ethernet interface support
- Can be configured to ignore short "unplugged" periods (-d option) or short "plugged" periods(`-u` option)
- Support for wireless networking. Whenever an association to an AP is detected the network is configured. Have a look on `waproamd` if you need a facility to configure WEP keys before AP associations succeed.
- Compatibility mode for network devices which do not support cable detection (`-F` option)

## Current Status

Version 0.28 is stable and has all the sensible features its users could think of.

## Documentation

Have a look on the man pages `ifplugd(8)`, `ifplugstatus(8)`, `ifplugd.conf(5)`. (An XSLT capable browser is required)

### Configuration

Edit `/etc/ifplugd/ifplugd.conf` for configuration changes. This file is a bourne shell script sourced by the init script and used to start `ifplugd` with appropriate arguments. You may specify more than one ethernet interface in `INTERFACES`. For each interface a seperate instance of `ifplugd` is spawned. The arguments specified in `ARGS` are append to `ifplugd`'s command line. Have a look on `ifplugd -h` or `man ifplugd` for further information about the available options.

The network interface which is controlled by `ifplugd` should not be configured automatically by your distribution's network subsystem, since `ifplugd` will do this for you if needed.

On Debian systems, any interfaces named in ifplugd's `INTERFACES` environment variable should not also be listed in an "auto" stanza in `/etc/network/interfaces`.

### Troubleshooting

When you are using the hotplug subsystem (Debian package `hotplug`) you may notice that the network device is configured even when it is not listed on an `auto` line in `/etc/network/interface`. This may be due to `hotplug` being configured to `ifup` the network interface when it becomes available. This was the default behavior in the Debian `hotplug` package prior to release `0.0.20030117-1`, for example. To prevent this you should either upgrade your `hotplug` package or comment out the `ifup` call in `/etc/hotplug/net.agent`.

When using `ifplugd` together with APM (and probably ACPI) suspends, strange things may happen: some network devices fail to detect the network cable for a short period of time before and after the suspend. When using the `-f` switch, this will be treated as "no link beat", thus the network is shutdown after a timeout. During this timeout the machine changes to suspended state. When it is resumed again, the timeout period will have expired and so the network is deconfigured, however, as the next cable detection succeeds, the network is configured again immediately. To fix this problem, `ifplugd` should be disabled before the APM suspend and enabled back after the suspend. This may be done by using `apmd` and adding a script to `/etc/apm/{suspend,resume}.d` which simply calls `/etc/init.d/ifplugd suspend`, resp. `/etc/init.d/ifplugd resume`. It might even be a good idea to shut down the network completely during suspend, this may be achieved by calling `/etc/init.d/ifplugd stop` and `/etc/init.d/ifplugd start` in the appropriate places. I strongly urge the packagers of this software for the Linux distributions to add such scripts to their packages.

### FAQ

1. Q: I want to use `ifplugd` with my PCMCIA device, but `ifplugd` quits when it doesn't find `eth0`, when I have not inserted the card. What can I do?

   A: Use the `-f` switch. This is not very clean however, since modprobe is called on each cable detection query of `ifplugd` to load a module for the network device. This is suboptimal. You should probably run `ifplugd` only when the card is really inserted.

2. Q: I am using the `-f` switch, but the kernel logs are getting filled with messages like "`modprobe: modprobe: Can't locate module eth0`". What can I do?

   A: Make sure you have a line like `alias eth0 off` in your `/etc/modules.conf`

3. Q: When the cable is unplugged and the interface shut down it is still available with `ifconfig` and markes as UP. Why this?

   A: `ifplugd` cannot detect the link beat with a shut down interface on certain (most as of kernel 2.4.19) network drivers. Thus `ifplugd` enables the interface before querying the link status. This may be switched off with -a flag. You might want to use it if you have a sane network driver (e.g. `eepro100`). The subdirectory `patches/` in the `ifplugd` distribution includes a patch for the 8139too 0.9.26 driver, which makes the driver compatible with -a. Don't ask me how to apply this patch. If you don't know, you won't need it.

4. Q: Does it work with anything else than plain ethernet or wireless LAN?

   A: Certainly not, since the `MII` and `ETHTOOL` `ioctl()`s and the wireless extension don't exist on other network device types.

5. Q: I have a Realtek 8139 based network card. Everytime `ifplugd` starts on bootup my machine freezes. What can I do?

   A: This is a bug in the `8139too` driver 0.9.25 (at least) shipped with Linux 2.4.19, please upgrade to `8139too` 0.9.26 (Linux 2.4.20 or seperately at http://www.sourceforge.net/projects/gkernel/).

6. Q: There are already `laptop-net`'s `ifd` and `miid`, why did you write your own daemon?

   A: `laptop-net` was too integrated with its profile system and didn't work on my hardware when I had a look on it. It seemed easier to me to write a simple but feature complete replacement than using laptop-net without most of the special features disabled. I didn't know about `miid` when I wrote `ifplugd`, but in any case `ifplugd` is much better than `miid`. For a comparison of `miid` and `ifplugd`, have a look on http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=162763&repeatmerged=yes

7. Q: I have two interfaces (e.g. WLAN and copper ethernet), both controlled by `ifplugd`, and want to force the network traffic to go over the faster one of them, in case both are available at the same time. How can I do this?

   A: A tool I wrote called `ifmetric` might be exactly what you're looking for.

## Requirements

A newer Linux Kernel (I think 2.2 is good enough, alltough I tested it only with 2.4) with a compatible device driver and ethernet card. Most modern cards and drivers are compatible, like mine which works with the `8139too` driver.

`ifplugd` was developed and tested on Debian GNU/Linux "testing" from July 2003, it should work on most other Linux distributions (and maybe Unix versions) since it uses GNU autoconf and GNU libtool for source code configuration and shared library management.

The machine used was a Medion 9580-F laptop with a Realtek 8139 network card and a PRISM1 PCMCIA wireless LAN card.

`ifplugd` needs `libdaemon`.

## Installation

As this package is made with the GNU autotools you should run `./configure` inside the distribution directory for configuring the source tree. After that you should run `make` for compilation and `make install` (as root) for installation of `ifplugd`.

The installation scripts create an init script in `${sysconfdir}/init.d/ifplugd`, however no `/etc/rc?.d/` links are created for it.

Extensive installation instructions for installation of `ifplugd` on Fedora Core 1 are available at Geoff Ericksson's web site.

## Acknowledgements

For the developers of `mii-diag`, `ethtool` and `laptop-net`, since I looked on their source codes for learning how to use the link beat ioctls.

Oliver Kurth for packaging `ifplugd` for Debian and `ifplugd`'s manpage

Stefan Seyfried, Thomas Hood, Asgeir Nilsen, Sean Reifschneider, R. Steve McKown, David Mitchell, Norbert Preining, Herbert Graeber for patches

Frederic Lepied for integrating `ifplugd` into Mandrake Linux

## Download

The newest release is always available from http://0pointer.de/lennart/projects/ifplugd/

The current release is 0.28

Get `ifplugd`'s development sources from the Subversion repository (viewcvs):

    svn checkout svn://seth.intheinter.net/ifplugd/trunk ifplugd

You may find an up to date Debian package of `ifplugd` on the Debian package repository.

`ifplugd` is nowadays included in many popular distributions (Mandrake, Gentoo, Suse, Debian, Ubuntu); Conectiva packages are available courtesy of Gonzalo Nemmi. Fedora Core packages are available from Dag Wieers.

If you want to be notified whenever I release a new version of this software use the subscription feature of Freshmeat.

New! There is a joint `ifplugd` and `waproamd` mailing list available.

$Id: README.html.in 124 2005-06-04 19:22:59Z lennart $