Designated router (DR) election method and router

Abstract

The present invention proposes a Designated Router (DR) election method and a router, wherein the method includes: each router in a protocol-independent multicast (PIM) network sends a Hello (Hello) message carrying a runtime option; the runtime option includes The time that the router has been running and the initial state duration of the PIM network expected by the router; each router receives the Hello message sent by each router in the PIM network, and according to the running time option carried by the Hello message, at All routers in the PIM network select a router that participates in the DR election, and elect a DR among the routers that participate in the election; the router that participates in the DR election starts running no later than the time when the PIM network starts to stabilize router. The present invention can avoid the phenomenon that multicast flow forwarding is interrupted after DR election.

Description

technical field [0001] The present invention relates to the technical field of Protocol Independent Multicast-Sparse Mode (PIM-SM, Protocol Independent Multicast-Sparse Mode), in particular to a designated router (DR, DesignatedRouter) election method and router. Background technique [0002] In the PIM-SM protocol, one of the multiple routers in the PIM network is elected as the DR, and the DR will be the only forwarder of multicast information in the PIM network, responsible for receiving multicast traffic from The broadcast traffic is forwarded to the client. [0003] The mode of DR election is: each router in the PIM network periodically sends Hello (Hello) message to each other, and this Hello message carries the DR priority of this router; DR priority, elect the router with the highest DR priority as the DR of the PIM network. If the DR priorities are the same, the router with the largest IP address is selected as the DR. When the DR fails, a new DR election process...

AI Technical Summary

Problems solved by technology

After the DR is switched to A, the unicast routing table of A may not be fully prepared at this time, which makes A unable to forward multicast traffic correctly.

[0005] It can be seen that the existing DR election mechanism does not consider some special cases. The DR device elected by the DR election algorithm based on full preemption may be a router that is not fully ready, which may cause interruption of multicast traffic forwarding.

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