Router and method for protocol process migration

摘要

A router and a method for migrating routing protocol processes or Virtual Routers (VRs) from one Route Processor (RP) to another using graceful restart procedures for maintaining packet flow to the router and assisting the router to obtain restart information. The router includes first and second RPs and a forwarding engine for forwarding packets to neighbor routers in the network. When the routing protocol process is terminated on the first RP, the neighbor routers detect a router failure and initiate the graceful restart procedures. A filter rule in the forwarding engine causes it to forward packets to the new routing protocol process on the second RP. The new process learns the network topology from the neighbor routers, and the migration is completed without packet loss and without requiring complex changes to the network protocol stack.