sudo vim /etc/netplan/50-cloud-init.yaml

network:
    version: 2
    ethernets:
        ens18:
            dhcp4: true
            match:
                macaddress: xx:xx:xx:xx:xx:xx
            set-name: ensxx
            addresses:
              - xxxx:xxxx:xx::1:xxx/yy
            gateway6: xxxx:xxxx:xx::1