Hi Paul,
thank you very much for your explanations! This solves my networking problems and the Ubuntu server is now part of my internal network behind ipfire.
Actually, I have used netplan for the networking definitions in Ubuntu and modified the file /etc/netplan/ 50-cloud-init.yaml; it now looks like this (check indentation of yaml file):
network:
version: 2
ethernets:
ens10:
dhcp4: no
addresses: [10.0.0.3/16]
routes:
- to: default
via: 10.0.0.1
nameservers:
addresses: [10.0.0.2, 1.1.1.1]
I have applied these settings with
netplan try
Cheers,
Holger