To answer my own question:
Firstly, Netplan is not an alternative to (systemd-)networkd or NetworkManager. Netplan is a "network configuration abstraction renderer", and for the example above, netplan actually creates a systemd-networkd file based on the netplan-configuration. It is saved as /run/systemd/network/10-netplan-enp3s0.network
, and the content is:
[Match]
Name=enp3s0
[Network]
LinkLocalAddressing=ipv6
Address=192.168.10.10/24
Address=2001:db8:6789::10/64
Gateway=192.168.10.1
Gateway=2001:db8:6789::1
DNS=192.168.10.5
DNS=2001:db8:6789::5
Domains=example.com
So, to add ip addrlabel
to my config, I had to create my own systemd-networkd-networkfile. It also needed to be (in lexical order) before the autogenerated file from netplan.
My solution was to create /etc/systemd/network/01-enp3s0.network
with the following content:
[Match]
Name=enp3s0
[Network]
LinkLocalAddressing=ipv6
Address=192.168.10.10/24
Address=2001:db8:6789::10/64
Gateway=192.168.10.1
Gateway=2001:db8:6789::1
DNS=192.168.10.5
DNS=2001:db8:6789::5
Domains=example.com
[IPv6AddressLabel]
Label=99
Prefix=2001:db8:6789::5/128
[IPv6AddressLabel]
Label=99
Prefix=2001:db8:6789::10/128