Patent ID: 9621378
Date: 2017-04-11
CPC Classifications: H04L

Claim:
1. A method carried out by a router, wherein the router is at least one of an autonomous system border router, an area border router, and a route reflector, the router is also a Border Gateway Protocol (BGP) speaker; and the router stores filtering information to limit the propagation of network layer reachability information (NLRI), wherein the filtering information comprises outbound route filtering information; the method comprising: receiving, from another BGP speaker, a BGP update message comprising NLRI specific to a virtual private network (VPN-NLRI), and path information comprising an address of a next hop for said VPN-NLRI; determining that there is no route to the next hop; modifying the filtering information to permit propagation of NLRI comprising the address of the next hop, responsive to the determining; and sending the modified filtering information to BGP neighbours of the router by advertising the outbound route filtering information to the router's BGP neighbours.