tsuchiya@GATEWAY.MITRE.ORG.UUCP (03/20/87)
Per you query about connecting two ethernet segments with different IP network numbers with bridges which route on ethernet address.... It seems you have two problems. First, getting your own IP-level gateways to know about the other net, and second, getting other boxes in the world to know that both nets are available through one interface. If you can solve the first problem, then the second problem is easy because you can address both nets via EGP (maybe I shouldn't assume EGP here, but I am guessing that RIP et al. can also do this). In solving the first problem, I would first ask whether the Bridges pass on broadcast ethernet addresses. If they do, then ARP can be used by the IP-level gateway to pass messages on to hosts irregardless of the IP-network number. If not, then somehow the IP-gateway has to have a local list of ethernet-address/IP-address tuples. Either way, the problem is a local one, and shouldn't REQUIRE both ethernets to have different network addresses (REQUIRE in the sense that the IP routing architecture breaks if you don't have one address). Also, if you want more that 254 hosts, to to a type B rather than a type A address. Type B will give you 65534 addresses. Type A network numbers are reserved for those REALLY BIG networks. Paul F. Tsuchiya