Summary
In this chapter, we modified the network topology to render single-segment FRR inapplicable. The adjustment necessitated that TI-LFA accommodates additional information and calculations, ensuring that the post-convergence path also serves as a backup path if there is a failure.
Following an increase in metric between the P8 and P4 routers from 10 to 100, the primary path from P8 to PE5 shifted to utilize the P2–P3 link, as observed in the traceroute of the primary path. Depending on whether the backup path carried the Node-SID of P8 or P4, distinct routing behaviors were noted – if using P8’s Node-SID, traffic would route back via P2, whereas with P4’s Node-SID, the route would proceed directly through P2–P3 due to the higher cost via P8–P4.
Visually, it became apparent that if there was a P2–P3 link failure, the post-convergence path would necessarily traverse P8 and P4 to reach PE5. Analysis of the backup path output...
