摘要 |
A scheme to achieve fast recovery from SRLG failures in the IP layer is described. An exemplary scheme, called multi-section shortest path first (“MSSPF”), builds on the idea of IP Fast Reroute (“IPFRR”), guarantees 100% recovery of SRLG failures and causes no dead loops. Given a source node, a destination node, and a shared risk group failure on a next hop from the source node to the destination node, failure recovery information may be determined by (1) accepting a graph representing network topology information including the source node and the destination node, (2) determining a node which is able to reach the destination node using a route which does not include the source node, wherein a path from the source node to the determined node is not affected by the shared risk group failure, and (3) storing, in association with the shared risk group failure, both (i) a network address associated with the determined node and (ii) an alternative output port of the source node using the shortest path from the source node to the determined node.
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