TRIGGERING PIM ASSERT RE-ELECTION TO HONOR NETWORK CONFIGURATION CHANGES

摘要

Exemplary systems, methods, apparatuses, and computer-readable media are provided for enabling PIM Assert re-election to be triggered to honor network configuration changes. Upon receipt of a PIM Join message for a multicast group, a router can enter a “Join” state and start an Expiry-Timer. Thereafter, the router may determine that it is an Assert-Loser for the multicast group via a PIM Assert election mechanism. At the expiration of the Expiry-Timer, instead of transitioning to a “No-Info” state and removing state for the multicast group, the router can, due to its status as the Assert-Loser for the multicast group, remain in the “Join” state and re-start the Expiry-Timer. Upon a later configuration change, the router can now automatically trigger a PIM Assert re-election, which can lead to the router potentially becoming the Assert-Winner without requiring a manual, traffic-disrupting intervention.

主权项

1. A method in a network element acting as a router for honoring routing configuration changes by triggering Protocol Independent Multicast (PIM) Assert re-election without multicast traffic interruption, the method comprising:
receiving, at the router, a PIM join message from a downstream router indicating that the router is to forward multicast traffic because it lies on a path between one or more senders and one or more receivers of a multicast group; starting, by the router as part of entering a Join state responsive to the receipt of the PIM join message, an Expiry-Timer associated with the multicast traffic; receiving, at the router, a first PIM Assert message from another router; determining, by the router based upon the first PIM Assert message, that the router is an Assert-Loser for the multicast traffic, wherein the another router is an Assert-Winner for the multicast traffic; and upon an expiry of the Expiry-Timer, based upon the router being the Assert-Loser, remaining in the Join state and restarting the Expiry-Timer.