Comment 7 for bug 1689346

Validated xenial yakkety and zesty render /# instead of /255.255.255.X
xenial START --------------

Internal State
!!python/object:cloudinit.net.network_state.NetworkState
_network_state:
    dns:
        nameservers:
        - 172.19.0.12
        search: []
    interfaces:
        eth1:
            address: null
            gateway: null
            inet: inet
            mac_address: aa:ab:ac:ad:ae:00
            mode: manual
            mtu: null
            name: eth1
            subnets:
            - address: 172.19.1.34
                ipv4: true
                netmask: 255.255.255.0
                routes:
                - gateway: 172.19.3.254
                    netmask: 0.0.0.0
                    network: 0.0.0.0
                type: static
            type: physical
    routes: []
    use_ipv6: false
_version: 1
use_ipv6: false

Checking out.d/etc/netplan/50-cloud-init.yaml ----

network:
    version: 2
    ethernets:
        eth1:
            addresses:
            - 172.19.1.34/24
            match:
                macaddress: aa:ab:ac:ad:ae:00
            nameservers:
                addresses:
                - 172.19.0.12
            routes:
            - to: 0.0.0.0/0
                via: 172.19.3.254
            set-name: eth1
cloud-init 0.7.9-153-g16a7302f-0ubuntu1~16.04.1
xenial DONE --------------
yakkety START --------------

Internal State
!!python/object:cloudinit.net.network_state.NetworkState
_network_state:
    dns:
        nameservers:
        - 172.19.0.12
        search: []
    interfaces:
        eth1:
            address: null
            gateway: null
            inet: inet
            mac_address: aa:ab:ac:ad:ae:00
            mode: manual
            mtu: null
            name: eth1
            subnets:
            - address: 172.19.1.34
                ipv4: true
                netmask: 255.255.255.0
                routes:
                - gateway: 172.19.3.254
                    netmask: 0.0.0.0
                    network: 0.0.0.0
                type: static
            type: physical
    routes: []
    use_ipv6: false
_version: 1
use_ipv6: false

Checking out.d/etc/netplan/50-cloud-init.yaml ----

network:
    version: 2
    ethernets:
        eth1:
            addresses:
            - 172.19.1.34/24
            match:
                macaddress: aa:ab:ac:ad:ae:00
            nameservers:
                addresses:
                - 172.19.0.12
            routes:
            - to: 0.0.0.0/0
                via: 172.19.3.254
            set-name: eth1
cloud-init 0.7.9-153-g16a7302f-0ubuntu1~16.10.1
yakkety DONE --------------
zesty START --------------

Internal State
!!python/object:cloudinit.net.network_state.NetworkState
_network_state:
    dns:
        nameservers:
        - 172.19.0.12
        search: []
    interfaces:
        eth1:
            address: null
            gateway: null
            inet: inet
            mac_address: aa:ab:ac:ad:ae:00
            mode: manual
            mtu: null
            name: eth1
            subnets:
            - address: 172.19.1.34
                ipv4: true
                netmask: 255.255.255.0
                routes:
                - gateway: 172.19.3.254
                    netmask: 0.0.0.0
                    network: 0.0.0.0
                type: static
            type: physical
    routes: []
    use_ipv6: false
_version: 1
use_ipv6: false

Checking out.d/etc/netplan/50-cloud-init.yaml ----

network:
    version: 2
    ethernets:
        eth1:
            addresses:
            - 172.19.1.34/24
            match:
                macaddress: aa:ab:ac:ad:ae:00
            nameservers:
                addresses:
                - 172.19.0.12
            routes:
            - to: 0.0.0.0/0
                via: 172.19.3.254
            set-name: eth1
cloud-init 0.7.9-153-g16a7302f-0ubuntu1~17.04.1
zesty DONE --------------