Posted 07 February 2011 - 12:13 PM
What are the routers? It would be easier if your routers were business class, say a SonicWALL, Watchguard or Cisco ASA. Then you could just designate each port, and run a Ethernet cable between the two of them. You would need to set up a NAT rule to forward LAN A traffic to that port, and the opposite for LAN B. In fact, one router could handle both ISPs and both networks.
Baltboy, assuming he's using residential routers, how would adding a third one help? It still has only one routable port, the WAN port. That could go into either of the other two's LAN ports, but all that would do is cascade the routers, it won't let you bridge between the two. It would allow two LANs to share one WAN, but not bridge two WANS - you need two configuarable ports for that. The switch ports won't forward traffic. Or do you have some other setup in mind?
There might be a Linux load that could do this for you, Aaron, but I doubt it. I'll take a look once you let me know the routers.