Отключаем systemd-resolved

systemctl disable --now systemd-resolved
cp /etc/resolv.conf /etc/resolv.conf.backup
sudo unlink /etc/resolv.conf
sudo touch /etc/resolv.conf

sudo mcedit /etc/resolv.conf

nameserver 8.8.8.8
nameserver 8.8.4.4

Конфигурация с тремя интерфейсами

mcedit /etc/netplan/config.yaml

network:
  ethernets:
    ens160:
      dhcp4: no
      addresses:
        - 192.168.150.170/24
      routes:
        - to: 192.168.250.0/24
          via: 192.168.150.100
    ens192:
      dhcp4: no
      addresses:
        - 89.89.89.174/28
    ens224:
      dhcp4: no
      addresses:
        - 212.212.212.70/29
      routes:
        - to: default
          via: 212.212.212.65

netplan apply

Второй пример

mcedit /etc/netplan/config.yaml

network:
  ethernets:
    ens160:
      dhcp4: no
      addresses:
        - 192.168.150.170/24
      routes:
        - to: default
          via: 192.168.150.100
        - to: 192.168.250.0/24
          via: 192.168.150.1
    ens192:
      dhcp4: no
      addresses:
        - 89.89.89.174/28
    ens224:
      dhcp4: no
      addresses:
        - 212.212.212.70/29

netplan apply