How to configure interface aliases using Systemd-Networkd?
Solution 1:
As Michael pointed out, you don’t.
Instead, you add additional Address= and Gateway= lines to the interface.
Example:
$ cat /etc/systemd/network/eth0.network
[Match]
Name=eth0
[Network]
Address=2a0a:3840:1337:126::b9c1:7ecb:1337/64
Gateway=2a0a:3840:1337:126::1
IPv6AcceptRA=no
Address=185.193.126.203/24
Gateway=185.193.126.1
DNS=95.215.19.53
[DHCP]
UseDNS=false