Restrictions and guidelines

The maximum interval for sending RA messages should be less than (or equal to) the router lifetime in RA messages. In this way, the router can be updated by an RA message before expiration.

The values of the NS retransmission timer and the reachable time configured for an interface are sent in RA messages to hosts. This interface sends NS messages at the interval of the NS retransmission timer and considers a neighbor reachable within the reachable time.