auto mgmtbr
iface mgmtbr inet static
    address {{ nsd_zones[0].ipv4_first_octets }}.1
    network {{ nsd_zones[0].ipv4_first_octets }}.0
    netmask 255.255.255.0
    broadcast {{ nsd_zones[0].ipv4_first_octets }}.255
    gateway {{ nsd_zones[0].ipv4_first_octets }}.1
    bridge_ports {{ mgmtbr_ext_interface }}
    dns-search {{ site_suffix }}
    dns-nameservers {{ dns_servers | join(" ") }}