Patent ID: 7801031

Claim:
For use by a router in a survivable network portion, a computer-implemented method comprising: a) receiving a packet addressed to a destination node within the survivable network portion, wherein the packet includes an information indicating that the packet has encountered a failure; and b) selecting one of (A) a primary port, (B) a primary backup port and (C) a secondary backup port on which to forward the received packet, such that, in the event of a double link failure, a backup path with no dead loops is defined, wherein the act of selecting one of (A) a primary port, (B) a primary backup port and (C) a secondary backup port for local rerouting includes 1) identifying a pattern of the failure; and 2) selecting, using a forwarding policy associated with the identified pattern, one of (A) a primary port, (B) a primary backup port and (C) a secondary backup port to use for forwarding.