Netplan is the new network management software for Ubuntu.
vim /etc/netplan/00-installer-config.yamlYou may have a different config file, but the /etc/netplan path is where you should look.
This is what my config file looks like.
network:
version: 2
ethernets:
ens18:
addresses:
- 172.16.3.4/24
nameservers:
addresses: [1.1.1.1, 1.1.1.2]
search: [rlskeels.com]
routes:
- to: default
via: 172.16.2.1netplan apply