The detailed relevant configuration looks like this:
LAN (lan) -> bridge0 -> v4: 192.168.1.1/24
DMZ (opt8) -> bridge1 -> v4: 192.168.80.1/24
LAN1 (opt18) -> ix0 ->
LAN2 (opt17) -> ix1 ->
DMZ1 (opt19) -> ix0.80 ->
DMZ2 (opt13) -> ix1.80 ->
and ifconfig shows this:
bridge0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
description: LAN
options=0
ether 58:9c:fc:10:ff:b7
inet 192.168.1.1 netmask 0xffffff00 broadcast 192.168.1.255
inet 192.168.1.5 netmask 0xffffffff broadcast 192.168.1.5
id 00:00:00:00:00:00 priority 32768 hellotime 2 fwddelay 15
maxage 20 holdcnt 6 proto rstp maxaddr 2000 timeout 1200
root id 00:00:00:00:00:00 priority 32768 ifcost 0 port 0
member: ix1 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
ifmaxaddr 0 port 6 priority 128 path cost 2000
member: ix0 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
ifmaxaddr 0 port 5 priority 128 path cost 2000
groups: bridge LOCAL
nd6 options=1<PERFORMNUD>
bridge1: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
description: DMZ
options=0
ether 58:9c:fc:10:ff:ed
inet 192.168.80.1 netmask 0xffffff00 broadcast 192.168.80.255
id 00:00:00:00:00:00 priority 32768 hellotime 2 fwddelay 15
maxage 20 holdcnt 6 proto rstp maxaddr 2000 timeout 1200
root id 00:00:00:00:00:00 priority 32768 ifcost 0 port 0
member: ix0.80 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
ifmaxaddr 0 port 17 priority 128 path cost 2000
member: ix1.80 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
ifmaxaddr 0 port 22 priority 128 path cost 2000
groups: bridge INTERNAL LOCAL
nd6 options=1<PERFORMNUD>
ix0: flags=1008943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
description: LAN1
options=4e138bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,WOL_UCAST,WOL_MCAST,WOL_MAGIC,VLAN_HWFILTER,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
ether 90:ec:77:34:9f:22
inet6 fe80::92ec:77ff:fe34:9f22%ix0 prefixlen 64 scopeid 0x5
groups: LOCAL
media: Ethernet autoselect (10Gbase-SR <full-duplex,rxpause,txpause>)
status: active
nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
ix1: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
description: LAN2
options=4e138bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,WOL_UCAST,WOL_MCAST,WOL_MAGIC,VLAN_HWFILTER,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
ether 90:ec:77:34:9f:23
inet6 fe80::92ec:77ff:fe34:9f23%ix1 prefixlen 64 scopeid 0x6
media: Ethernet autoselect
status: no carrier
nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
ix0.80: flags=1008943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
description: DMZ1
options=4600003<RXCSUM,TXCSUM,RXCSUM_IPV6,TXCSUM_IPV6,MEXTPG>
ether 90:ec:77:34:9f:22
inet6 fe80::92ec:77ff:fe34:9f22%ix0.80 prefixlen 64 scopeid 0x11
groups: vlan INTERNAL LOCAL
vlan: 80 vlanproto: 802.1q vlanpcp: 0 parent interface: ix0
media: Ethernet autoselect (10Gbase-SR <full-duplex,rxpause,txpause>)
status: active
nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
ix1.80: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
description: DMZ2
options=4600003<RXCSUM,TXCSUM,RXCSUM_IPV6,TXCSUM_IPV6,MEXTPG>
ether 90:ec:77:34:9f:23
inet6 fe80::92ec:77ff:fe34:9f23%ix1.80 prefixlen 64 scopeid 0x16
groups: vlan
vlan: 80 vlanproto: 802.1q vlanpcp: 0 parent interface: ix1
media: Ethernet autoselect
status: no carrier
nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>