Patent ID: 9590845
Date: 2017-03-07
CPC Classifications: H04L

Claim:
1. A method comprising: by a network device, determining, based on network topology information obtained by an interior gateway protocol (IGP) executed by the network device, that a protected node along a primary label switched path (LSP) is a first area border router at a border of a first IGP area and a second IGP area, wherein the protected node and the network device are positioned in the first IGP area; in response to determining that the protected node is a first area border router, by the network device, identifying a second area border router in the first IGP area in which the network device and the protected node are positioned, wherein the second area border router is located at the border of the first IGP area and the second IGP area; by the network device, automatically establishing a bypass LSP to the second area border router, wherein the bypass LSP follows a path that avoids the protected node; by the network device, automatically establishing a targeted label distribution protocol (LDP) session to the second area border router; by the network device, obtaining a label mapping from the second area border router using the targeted LDP session; and by the network device, programming stored forwarding information to include a backup path to the second area border router with a label stack having an inner label from the obtained label mapping for the second area border router and an outer label for the bypass LSP to the second area border router.