Network Protocol Manager initiates a discovery cycle of the routing topology objects whenever:
IP Availability Manager is added as a source to Network Protocol Manager, as explained in Chapter 4, “Preparing and Initiating Discovery.”
IP Availability Manager completes a discovery cycle.
By default, each time IP Availability Manager completes a discovery cycle, Network Protocol Manager performs a topology synchronization to import device topology information from IP Availability Manager. It then performs its own discovery by sending SNMP requests or CLI commands to the devices to discover or rediscover routing topology objects.
Network Protocol Manager is restarted or communication is lost and then reestablished between Network Protocol Manager and IP Availability Manager.