--- name: "ifplugd" section: "8" platform: "linux" package: "ifplugd" version: "0.28-18" release: "Arch Linux 2026-11-01" platforms: ["linux"] url: "https://new.carta.tech/ifplugd" --- # ifplugd(8) A link detection daemon for ethernet devices ## NAME ifplugd - A link detection daemon for ethernet devices ## SYNOPSIS **ifplugd \[***options***\]** ## DESCRIPTION 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. ## OPTIONS - **-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** Show 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** Show 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.) ## FILES */etc/ifplugd/ifplugd.conf*: 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.\.pid*: the pid file for ifplugd. ## ENVIRONMENT 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. ## SIGNALS *SIGINT, SIGTERM* 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) ## AUTHOR ifplugd was written by Lennart Poettering \. ifplugd is available at **http://0pointer.de/lennart/projects/ifplugd/** ## SEE ALSO **[ifplugd.conf(5)](/ifplugd.conf/5.md)**, **[ifup(8)](/ifup/8.md)**, **[interfaces(5)](/interfaces/5.md)**, **[ifconfig(8)](/ifconfig/8.md)**, **[ifplugstatus(8)](/ifplugstatus/8.md)** ## COMMENTS This man page was written using **[xmltoman(1)](/xmltoman/1.md)** by Oliver Kurth.