Section: Maintenance Commands (8)
ifplugd - A link detection daemon for ethernet devices
ifplugd is a 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 on-board network adapters, since it will only configure the interface when a cable is really connected.
It uses your distribution's native ifup/ifdown programs, but can be configured to do anything you wish when the state of the interface changes. It may ignore short unplugged whiles (-d option) or plugged whiles (-u option).
ifplugd may be used in "compatibility mode" by specifying -F on the command line. Than ifplugd will treat network drivers which do not support link beat querying as always online.
- -a | --no-auto
Do not enable interface automatically (default: off)
- -n | --no-daemon
Do not daemonize (for debugging) (default: off)
- -s | --no-syslog
Do not use syslog, use stdout instead (for debugging) (default: off).
- -b | --no-beep
Do not beep (off)
- -f | --ignore-fail
Ignore detection failure, retry instead. Failure is treated as "no link". (default: off)
- -F | --ignore-fail-positive
Ignore detection failure, retry instead. Failure is treated as "link detected". (default: off)
- -i | --iface= IFACE
Specify ethernet interface (default: eth0)
- -r | --run= EXEC
Specify program to execute when link status changes (default: /etc/ifplugd/ifplugd.action)
- -I | --ignore-retval
Don't exit on nonzero return value of program executed on link change. (default: off)
- -t | --poll-time= SECS
Specify poll time in seconds (default: 1)
- -u | --delay-up= SECS
Specify delay for configuring interface (default: 0)
- -d | --delay-down= SECS
Specify delay for deconfiguring interface (default: 5)
- -m | --api-mode= MODE
Force a specific link beat detection ioctl() API. Possible values are auto, iff, wlan, ethtool, mii, and priv for automatic detection, interface flag (IFF_RUNNING), wireless extension, SIOCETHTOOL, SIOCGMIIREG resp. SIOCPRIV. Only the first character of the argument is relevant, case insensitive. (default: auto)
- -p | --no-startup
Don't call the script to bring up network on deamon start (default: off)
- -q | --no-shutdown
Don't call the script for network shutdown on deamon quit (default: off)
- -w | --wait-on-fork
When daemonizing, wait until the background process finished with the initial link beat detection. When this is enabled, the parent process will return the link status on exit. 1 means link beat detected, 2 stands for link beat not detected, everything else is an error.
- -W | --wait-on-kill
When killing a running daemon (with -k) wait until the daemon died.
- -x | --extra-arg= ARG
Specify an extra argument to be passed to the action script.
- -M | --monitor
Don't fail when the network interface is not available, instead use NETLINK to monitor device avaibility. The is useful for PCMCIA devices and similar.
- -h | --help
- -k | --kill
Kill a running daemon (Specify -i to select the daemon instance to kill)
- -c | --check-running
Check if a daemon is running for a given network interface. Sets the return value to 0 if a daemon is already running or to 255 if not.
- -v | --version
- -S | --supend
Suspend a running daemon. The daemon will no longer check the link status until it is resumed (-R) again. (Specify -i to select the daemon instance to suspend.)
- -R | --resume
Resume a suspended daemon. (Specify -i to select the daemon instance to resume.)
- -z | --info
Request that a running daemon shall write its status information to syslog. (Specify -i to select the daemon instance to send the request to.)
: this file is sourced by the init script /etc/init.d/ifplugd
and contains the interface to be monitored and the options to be used.
/etc/ifplugd/ifplugd.action: this is the script which will be called by the daemon whenever the state of the interface changes. It takes two areguments: the first is the interface name (eg. eth0), the second either "up" or "down".
/var/run/ifplugd.<iface>.pid: the pid file for ifplugd.
The action script will be called with two environment variables set:
IFPLUGD_PREVIOUS The previous link status. Either "up", "down", "error" or "disabled". The former values should be obvious, the latter is set on daemon startup.
IFPLUGD_CURRENT The current link status. See above for possible values.
ifplugd will quit, possibly running the shutdown script. This is issued by passing -k to ifplugd.
SIGQUIT ifplugd will quit, the shutdown script is never run.
SIGHUP ifplugd will write its status information to syslog. This is issued by -z.
SIGUSR1 ifplugd will go to suspend mode. (-S)
SIGUSR2 ifplugd will resume from suspend mode. (-R)
ifplugd was written by Lennart Poettering <mzvscyhtq (at) 0pointer (dot) de>. ifplugd is available at http://0pointer.de/lennart/projects/ifplugd/
This man page was written using xmltoman(1)
by Oliver Kurth.