I have a Barracuda 330 appliance in firewall disabled mode and find that, with two unique ISP connections in place (WAN1 and WAN2), if I simulate a loss of WAN1 link (by way of unplugging the cable on WAN1 or shutting down WAN1's upstream switch interface), the link balancer stops forwarding all outbound traffic even though WAN2 is still connected to ISP2.
While both WAN links are up, I can force successful switching of outbound traffic between WAN interfaces by inducing DNS test failures on them. No issues bouncing between both my ISPs.
The fact that a loss the physical connection to WAN1 interface stops all outbound traffic on both WAN interfaces is concerning as it goes against the biggest reason for getting the unit in the first place.
Any feedback would be greatly appreciated.