When using the setup utility to configure a redundant pair, you are asked to provide...

When establishing a redundant pair, each device must know where to send its health heartbeats and sync data.

The Peer IP: The Failover Peer IP is the IP address belonging to the other BIG-IP device in the HA pair. This is typically a34 Self-IP on a dedicated "HA" or "Internal" VLAN, or the Management IP.

Purpose: It identifies the destination for the "Heartbeat" (the "Are you alive?" check).

Setup Context: During the initial setup, you tell Device A to look for Device B at its "Failover Peer IP," and you tell Device B to look for Device A at its respective "Failover Peer IP."