RSH permissions

Hello, I am building a small two computer cluster on the Suse OS and i'm having troubles with the networking. The two computers are connected on a LAN and are able to communicate with each other properly. I can also access a remote shell with rsh cpu2, however when i try to add a command "rsh cpu2 ll" for example, it gives an error message "cpu2 connection refused". Does any one have any basic trouble shooting type ideas to set me on the right path? Any help would be greatly appreciated. cheers, Jonathan Fuchser