Dwight

You can certainly route between the FastEthernet ports of the 1841. Eash FastEthernet is an independent routed layer 3 interface. I have set this up a number of times and it works quite well. Just put an IP address and subnet mask on FastEthernet0/0 and another IP address and subnet mask on FastEthernet0/1. The 1841 automatically routes between these subnets. Of course you will need some source of routing information (static routes or dynamic routing protocol) for networks and subnets that are not locally connected.

HTH

Rick