Patent ID: 8396988

Claim:
A method for retaining routes in a control plane learned by an inter-domain routing protocol in an event of a connectivity failure between a first router and a second router, comprising: classifying the first router as one of a route reflector and an originator; classifying the second router as one of the route reflector and the originator; determining whether a particular originator is still visible in an interior gateway protocol domain in response to determining that the connectivity failure occurred between the particular originator and a particular route reflector, wherein the particular route reflector is one of the first router and the second router and the particular originator is the other of the first router and the second router; determining whether to propagate a withdrawal of learned routes having a next hop attribute equal to the particular originator based on classification of the first router, classification of the second router, and whether the particular originator is still visible in the interior gateway protocol domain; determining whether to abstain from propagating the withdrawal of learned routes if the connectivity failure occurred between the particular route reflector and the particular originator, and the particular originator is accessible via an intra-domain routing protocol; abstaining from propagating a withdrawal of learned routes based on classification of the first router as a route reflector and classification of the second router as a route reflector; and propagating a withdrawal of learned routes associated with an originator based on classification of the first router as an originator and classification of the second router as an originator.