My customer has two spare networks: 192.168.0.0 and 192.168.1.0. They're physically connected by CAT5 cable. What should I configure and where so that the host of each network can connect to the other host in the other network?
Additionally, they have two subnets (after subnetting a class B network), that are physically connected by a CAT5 cable. What should I configure and where so that the host of each network can connect to the other host in the other network?
If the two networks have a router between them, then you should configure the routing table for each host on the 192.168.0.0 network to use that router as the next hop for the 192.168.1.0 network and similarly for the hosts on the 192.168.1.0 network.
If there is no router -- so that there is really only a single physical network -- then your best bet would be to configure the addresses of all the hosts as /23. With that change, no additional routing configuration is necessary. If we think of these four networks in terms of CIDR addressing, we see that your two questions are really the same question, so the answer to the second is the same as the answer to the first.
This was first published in March 2007