create alias for network link using systemd-networkd configuration

Question

I want to add aliases to my network links to use them as short descriptions. I am configuring my interfaces using systemd-networkd, having systemd version 241 on a debian buster server.

I've created the file -rw-r--r-- 1 root root 68 Feb 9 12:53 /etc/systemd/network/ens19.link with the content:

[MATCH] MACAddress=7a:08:e8:12:fc:c7 [LINK] Alias=myalias 

I've tried to reboot the system, but the alias does not appear:

3: ens19: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000 link/ether 7a:08:e8:12:fc:c7 brd ff:ff:ff:ff:ff:ff 

Doing ip l set ens19 alias myalias gives the intended result:

3: ens19: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000 link/ether 7a:08:e8:12:fc:c7 brd ff:ff:ff:ff:ff:ff alias myalias 

How can I achieve that using systemd-networkd?

Answer 1

I should have read the manual more carefully.

The first (in lexical order) of the link files that matches a given device is applied. Note that a default file 99-default.link is shipped by the system. Any user-supplied .link should hence have a lexically earlier name to be considered at all.

Renaming /etc/systemd/network/ens19.link to /etc/systemd/network/00-ens19.link helped.

[MATCH] should be [Match] and [LINK] should be [Link].

To apply a changed .link file to the link I can reboot or run

udevadm test-builtin net_setup_link /sys/class/net/ens19 

(Because .link files are processed by udev and not systemd-networkd, restarting systemd-networkd is insufficient.)

Answer 2

As per systemd.network link aliases are not (yet?) supported.