Patent ID: 8824334

Claim:
A method comprising: determining an identity of each peer device in a second routing domain attached to an edge device in a first routing domain and one or more nodes in the second routing domain, wherein the edge device is configured to identify one or more shared risk node groups (SRNG) corresponding to one or more peer devices in the second routing domain; receiving, from other edge devices in the first routing domain, identities of peer devices in the second routing domain attached to the other edge devices; associating, by the edge device in the first routing domain, each address prefix of the one or more nodes in the second routing domain with an identity of each peer device in the second routing domain that advertised the address prefix and with an identity of one or more edge devices in the first routing domain to which that peer device is attached, wherein the address prefix is advertised using at least one protocol selected from the group comprising Border Gateway Protocol (BGP), Open Shortest Path First (OSPF), and Intermediate-System-to-Intermediate-System (IS-IS); determining, by the edge device in the first routing domain, a specific address prefix is associated with a same identity of a peer device in the second routing domain but with different edge devices in the first routing domain; and assigning the different edge devices in the first routing domain associated with the specific address prefix to a shared risk node group (SRNG) corresponding to the peer device in the second routing domain.