Domino R5 Clustering Question Relative T

We’re going to be setting up 2 Domino R5 servers and they’ll be clustered. What does the TCP/IP addressing look like in this scenario? Does each server have its own IP address? Or does the cluster itself have its own IP address? We’re thinking that the cluster should have its own IP address so that all incoming traffic can be routed to the cluster entity and we’d get true benefit from load balancing. If our ISP has to direct traffic to one of the servers in the cluster, that seems to defeat the purpose.

Anyone know?