ifplugd
ifplugd
is an Ethernet link-state monitoring daemon that executes user-specified scripts to configure an Ethernet device when a cable is plugged in, or automatically unconfigure an Ethernet device when a cable is removed. Follow the steps below to install and configure the ifplugd
daemon.
Install ifplugd
You can install this package even if the switch is not connected to the internet, as it is contained in the cumulus-local-apt-archive
repository that is embedded in the Cumulus Linux disk image.
To install ifplugd
:
Update the switch before installing the daemon:
cumulus@switch:~$ sudo -E apt-get update
Install the
ifplugd
package:cumulus@switch:~$ sudo -E apt-get install ifplugd
Configure ifplugd
After you install ifplugd
, you must edit two configuration files:
/etc/default/ifplugd
/etc/ifplugd/action.d/ifupdown
The example configuration below configures ifplugd
to bring down all uplinks when the peer bond goes down in an MLAG environment.
Open
/etc/default/ifplugd
in a text editor and configure the file as appropriate. Add thepeerbond
name before you save the file.INTERFACES="peerbond" HOTPLUG_INTERFACES="" ARGS="-q -f -u0 -d1 -w -I" SUSPEND_ACTION="stop"
Open the
/etc/ifplugd/action.d/ifupdown
file in a text editor. Configure the script, then save the file.#!/bin/sh set -e case "$2" in up) clagrole=$(clagctl | grep "Our Priority" | awk '{print $8}') if [ "$clagrole" = "secondary" ] then #List all the interfaces below to bring up when clag peerbond comes up. for interface in swp1 bond1 bond3 bond4 do echo "bringing up : $interface" ip link set $interface up done fi ;; down) clagrole=$(clagctl | grep "Our Priority" | awk '{print $8}') if [ "$clagrole" = "secondary" ] then #List all the interfaces below to bring down when clag peerbond goes down. for interface in swp1 bond1 bond3 bond4 do echo "bringing down : $interface" ip link set $interface down done fi ;; esac
Restart the
ifplugd
daemon to implement the changes:cumulus@switch:~$ sudo systemctl restart ifplugd.service
Caveats and Errata
The default shell for ifplugd
is dash
(/bin/sh
) instead of bash
, as it provides a faster and more nimble shell. However, dash
contains fewer features than bash
(for example, dash
is unable to handle multiple uplinks).