How is it implemented?

NT 4.0 is set up with a two IP RAS pool, you dial in , and want to access another node on the network. When you try to connect, you receive access denied. The fix is to configure the all nodes you will access, with the exact same RAS pool as the one you dial in to. The other nodes check your IP address for authentification. This is for access to web services on the other node, or PCanywhere access to the node via network after connecting via RAS on another box. How is this implemented?