$ cat /etc/netplan/50-cloud-init.yaml
# This file is generated from information provided by the datasource.  Changes
# to it will not persist across an instance reboot.  To disable cloud-init's
# network configuration capabilities, write a file
# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
# network: {config: disabled}
network:
    bridges:
        ovs-br:
            addresses:
            - 172.16.99.15/24
            gateway4: 172.16.99.1
            interfaces:
            - ens4
            macaddress: 52:54:00:d9:08:1c
            mtu: 1500
            nameservers:
                addresses:
                - 172.16.99.2
                search:
                - maas
            openvswitch: {}
            parameters:
                forward-delay: 15
                stp: false
    ethernets:
        ens4:
            match:
                macaddress: 52:54:00:d9:08:1c
            mtu: 1500
            set-name: ens4
    version: 2

#$ ip route
#default via 172.16.99.1 dev ovs-br proto static 
#172.16.99.0/24 dev ovs-br proto kernel scope link src 172.16.99.15