Establishing RLFA Tunnel
To calculate the Remote LFA backup path and to determines the Remote LFA node the software requirement can be broadly classified as below:
IS-IS
ISIS shall calculate Repair path that are P space (routers it can reach without traversing the protected link) and Q space (routers that can reach the protected destination without traversing the protected link). Hence routers that belong to both spaces called as PQ routers has to be calculated. It has to inform LDP about PQ node so that RLFA tunnel can be established.
LDP
LDP shall establish targeted session with PQ node and shall advertise label to peer node for the destination FEC. LDP shall send primary and backup path FTN/ILM add/delete info to NSM for further programing.
NSM
NSM shall maintain Primary and Backup path FTN/ILM and shall send information to HSL for data-plane programing.
HSL
HSL program primary and backup FTN/ILM entry in hardware.
Last modified date: 10/17/2023