I have 2 1841 routers in a lab config. Both routers have CSU modules in them and I am using a T1 crossover cable to connect them together. After configuring IP addresses on both sides I can ping the serial interfaces from each of the routers, but I cannot go past the interfaces? I configure EIGRP and added the network, but when I do a "sh ip route" no routes for the networks on the other router show up. I am not sure what I am missing? Any advice anyone has would be great.