During the Replicated Data Cluster configuration process you will create virtual IP addresses for the following:
Virtual SQL Server
The IP address should be the same on all nodes at the primary and secondary zones.
Replication IP address for the primary zone
Replication IP address for the secondary zone
You should have these IP addresses available before you start deploying the RDC environment (for an IPv4 network, you will need to specify the addresses; for an IPv6 network, they are generated).