I never set the bridge interfaces manually. Here is a screenshot from Network / Interfaces in the TrueNAS Core 13.0-U4 GUI.
Code:
root@RyzenNAS:~ # ifconfig
igb0: flags=8822<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=4e527bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,WOL_MAGIC,VLAN_HWFILTER,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6,NOMAP>
ether 70:85:c2:5a:9f:42
media: Ethernet autoselect
status: no carrier
nd6 options=9<PERFORMNUD,IFDISABLED>
cxl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=8800b8<VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,LINKSTATE>
ether 00:07:43:5b:95:20
media: Ethernet none
status: no carrier
nd6 options=9<PERFORMNUD,IFDISABLED>
cxl1: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=8800b8<VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,LINKSTATE>
ether 00:07:43:5b:95:28
inet 10.13.37.10 netmask 0xffffff00 broadcast 10.13.37.255
media: Ethernet 10Gbase-Twinax <full-duplex,rxpause,txpause>
status: active
nd6 options=9<PERFORMNUD,IFDISABLED>
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
options=680003<RXCSUM,TXCSUM,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6>
inet6 ::1 prefixlen 128
inet6 fe80::1%lo0 prefixlen 64 scopeid 0x4
inet 127.0.0.1 netmask 0xff000000
groups: lo
nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
pflog0: flags=0<> metric 0 mtu 33160
groups: pflog
bridge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
ether 58:9c:fc:00:2a:14
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: vnet0.8 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
ifmaxaddr 0 port 14 priority 128 path cost 2000
member: vnet0.7 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
ifmaxaddr 0 port 13 priority 128 path cost 2000
member: vnet0.6 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
ifmaxaddr 0 port 12 priority 128 path cost 2000
member: vnet0.5 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
ifmaxaddr 0 port 9 priority 128 path cost 2000
member: vnet2 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
ifmaxaddr 0 port 11 priority 128 path cost 2000000
member: vnet1 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
ifmaxaddr 0 port 10 priority 128 path cost 2000000
member: vnet0 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
ifmaxaddr 0 port 7 priority 128 path cost 2000000
member: cxl1 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
ifmaxaddr 0 port 3 priority 128 path cost 2000
groups: bridge
nd6 options=9<PERFORMNUD,IFDISABLED>
vnet0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=80000<LINKSTATE>
ether fe:a0:98:04:51:ff
hwaddr 58:9c:fc:10:f9:4e
groups: tap
media: Ethernet autoselect
status: active
nd6 options=9<PERFORMNUD,IFDISABLED>
Opened by PID 2212
bridge1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
ether 58:9c:fc:10:ff:d1
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
groups: bridge
nd6 options=9<PERFORMNUD,IFDISABLED>
vnet1: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=80000<LINKSTATE>
ether fe:a0:98:55:27:78
hwaddr 58:9c:fc:10:08:37
groups: tap
media: Ethernet autoselect
status: active
nd6 options=9<PERFORMNUD,IFDISABLED>
Opened by PID 2282
vnet2: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=80000<LINKSTATE>
ether fe:a0:98:5f:ac:b3
hwaddr 58:9c:fc:00:2b:00
groups: tap
media: Ethernet autoselect
status: active
nd6 options=9<PERFORMNUD,IFDISABLED>
Opened by PID 2350
vnet0.5: flags=8963<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
description: associated with jail: *** as nic: epair0b
options=8<VLAN_MTU>
ether 70:85:c2:31:41:ea
hwaddr 02:4e:8b:8d:84:0a
groups: epair
media: Ethernet 10Gbase-T (10Gbase-T <full-duplex>)
status: active
nd6 options=9<PERFORMNUD,IFDISABLED>
vnet0.6: flags=8963<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
description: associated with jail: *** as nic: epair0b
options=8<VLAN_MTU>
ether 02:ff:60:33:ee:98
hwaddr 02:a3:03:67:ae:0a
groups: epair
media: Ethernet 10Gbase-T (10Gbase-T <full-duplex>)
status: active
nd6 options=9<PERFORMNUD,IFDISABLED>
vnet0.7: flags=8963<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
description: associated with jail: *** as nic: epair0b
options=8<VLAN_MTU>
ether 02:07:43:c8:bc:a3
hwaddr 02:5f:2d:d5:d9:0a
groups: epair
media: Ethernet 10Gbase-T (10Gbase-T <full-duplex>)
status: active
nd6 options=9<PERFORMNUD,IFDISABLED>
vnet0.8: flags=8963<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
description: associated with jail: *** as nic: epair0b
options=8<VLAN_MTU>
ether 70:85:c2:8b:86:16
hwaddr 02:71:38:8e:8b:0a
groups: epair
media: Ethernet 10Gbase-T (10Gbase-T <full-duplex>)
status: active
nd6 options=9<PERFORMNUD,IFDISABLED>