It is finally resolved!
So here is the thing, for some reason the jails that aren’t VMIMAGE type jails do not have an assigned IP on the loopback, that’s just how it is.
No amount of messing with ifconfig fixed anything.
No rc.conf changes fixed anything.
But I read in a number of places that setting up an alias can do the trick.
And that’s dead easy in FreeNAS, I remembered there is something on the jail config, and sure enough:
“IPV4 Aliases”, that configuration field on the jail setup in FreeNAS, can be given “127.0.0.1” and voila:
root@plexmediaserver_1:/ # ifconfig
igb0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=403bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,VLAN_HWTSO>
ether 0c:c4:7a:31:3e:06
inet 192.168.1.227 netmask 0xffffffe0 broadcast 192.168.1.255
inet 127.0.0.1 netmask 0xff000000 broadcast 127.255.255.255
media: Ethernet autoselect (1000baseT <full-duplex>)
status: active
igb1: flags=8c02<BROADCAST,OACTIVE,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=403bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,VLAN_HWTSO>
ether 0c:c4:7a:31:3e:07
media: Ethernet autoselect
status: no carrier
ipfw0: flags=8801<UP,SIMPLEX,MULTICAST> metric 0 mtu 65536
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
options=600003<RXCSUM,TXCSUM,RXCSUM_IPV6,TXCSUM_IPV6>
inet 127.0.0.1 netmask 0xff000000
root@plexmediaserver_1:/ #
And sure enough the Plex Media Server.log now reads
Plex Media Server.log.2:Oct 15, 2015 21:27:28 [0x809795000] DEBUG - * 6 lo0 (127.0.0.1) (loopback: 1)
Now the Roku is getting its images. Everyone’s happy. Thank you MovieFan and sa2000 for your help, and pointing out the loopback interface issue.