Let's say there are 2 bridges: bridge0 and bridge100, and a jail which is supposed to be connected to both of them:
Then jail is configured using WebUI:
Network properties>interfaces: vnet0:bridge0;vnet1:bridge100
- IPv4 Interface: vnet0:bridge0 | IP: 192.168.1.2/24
- IPv4 Interface: vnet1:bridge100 | IP: 192.168.2.2/24
Jail fails to start with such configuration, vaguely complaining about VNET issues.
Jail's config.json has such lines:
"interfaces": "vnet0:bridge0,vnet1:bridge100", "ip4_addr": "vnet0:bridge0|192.168.1.2/24,vnet1:bridge100|192.168.2.2/24",
If "ip4_addr" is changed to "vnet0|192.168.1.2/24,vnet1|192.168.2.2/24", then jail starts successfully with correct IPs and virtual interfaces attached to correct bridges.
It seems "IPv4 Interface" dropdown in "Basic properties" is populated with values from "interfaces" in "Network properties" without trimming the colons and bridge names after them, and that is why config via WebUI fails.