pfSense

As reported by a user here http://forum.pfsense.org/index.php/topic,28442.0.html (And experienced by myself last week)

If you have three or more Interfaces in a CARP+Bridging scenario on 1.2.3 or 2.0 it can cause issues, either in general or perhaps only when NAT is involved.

• Add CARP VIPs to WAN
• NAT LAN to a CARP VIP
• Bridge OPT1 to WAN

In my case I has CARP on LAN as well, and a sync interface, and a backup unit going. Active unit would stay alive anywhere from 30 seconds to an hour, then lock up tight. The secondary would take over, and then eventually fail. If the primary was immediately rebooted by hand, the backup unit would stay up indefinitely.

When it got hung up, it was not responsive to ping, nor console input. No panic, no reboot, just seized up. One time pressing the power button on the unit did result in the console printing an error that it was not in the proper state to handle the event.

We don't recommend CARP+Bridging anyhow, but it might be nice to know what is going on that makes it lock that severely.