Systemd's networkd will drop IP-Addresses configured by other processes like Keepalived's VRRP, when it is restarted. This may happens on updates.
To prevent this following settings are required in
v242 or earlier (even if you do not use DHCP client in networkd)
v243 or newer
If there is netplan in place these files will be generated.
critical: yes to
eth1: addresses: - 192.0.2.67/24 gateway4: 192.0.2.1 nameservers: addresses: - 198.51.100.42 - 198.51.100.53 search: - example.lcal critical: yes
This will add the
CriticalConnection to your networkd configuration.