Routing Only Mode – Switch Drops Out
I have a setup that I am absolutely at my wits end over. I have a service provider routing a /25 to me through another public IP. I am using pfSense 1.23 Release in a "router only" mode (Advanced options, routing platform only checked). I have the single public on my WAN and the first IP of the routed block on my LAN. The LAN acts as the gateway for all clients downstream of it. I have used this setup enumerable times in the past successfully. This particular setup worked perfectly while there was only a single client connected directly to the LAN port via a straight through RJ45 connection to their router. The problem I am having, starts when I add a switch to the mix. Needing to add another client, I connected a switch to the LAN port and connected both clients to the switch. This setup works for anywhere from 5 minutes to several hours but eventually I loose connectivity to the clients. If I reboot the switch everything begins working again. I have tried three different switches. I have tried running pfSense on ALIX hardware as well as a workstation class machine with two Intel Server NICs. I have even tried doing a hub and spoke setup where the boarder router routes to a spoke router and THEN plugging the switch in but I still get the same results. If I introduce a switch anywhere in the mix it eventually stops responding. Anyone have any suggestions? I'm out of ideas.
Sounds like something plugging into that switch is causing a layer 2 loop - two bridged NICs going to the same switch, for one, would do that. The switch will work for a few minutes until some traffic starts going around and around and then it eventually melts down.