Custom network interface names

2020-12-05T10:11:41Z

Oleksandr: /* /etc/mdev.conf configuration */

This article shows how to rename/change name of a network interface.

Alpine Linux uses ''busybox'' ''mdev'' to manage devices in ''/dev''. ''mdev'' reads ''/etc/mdev.conf'' and according to [https://git.busybox.net/busybox/plain/docs/mdev.txt mdev documentation] one can define a command to be executed per device definition. The command which is going to be used to change network interface name is ''nameif''.

== ''/etc/mdev.conf'' configuration ==
<pre>
-SUBSYSTEM=net;DEVPATH=.*/net/.*;.* root:root 600 @/sbin/nameif -s
</pre>

Here we tell ''mdev'' to call ''nameif'' for devices found in ''/sys/class/net/''.

<pre>
# ls -d -C -1 /sys/class/net/eth*
/sys/class/net/eth1
/sys/class/net/eth2
/sys/class/net/eth3
/sys/class/net/eth4
/sys/class/net/eth5
</pre>

== ''nameif'' configuration ==

''nameif'' itself reads ''/etc/mactab'' by default. Example line for a network interface with following hwaddr

<pre>
# cat /sys/class/net/eth0/address
90:e2:ba:04:28:c0
</pre>

would be

<pre>
# grep 90:e2:ba:04:28:c0 /etc/mactab
dmz0 90:e2:ba:04:28:c0
</pre>

== ramdisk rebuild ==

''/etc/mdev.conf'' is part of ramdisk

<pre>
# grep /etc/mdev.conf /etc/mkinitfs/features.d/*.files
/etc/mkinitfs/features.d/base.files:/etc/mdev.conf
</pre>

thus we need to rebuild ramdisk

<pre>
# mkinitfs $(ls /lib/modules/)
==> initramfs: creating /boot/initramfs-lts
</pre>

== finalization ==

To use renamed network interface without reboot, just call ''nameif'' while the network interface is down.

<pre>
# nameif -s
</pre>

And finally reboot...

[[Category:Networking]]

Alpine Linux - User contributions [en]

Custom network interface names