Understanding backup path calculation
In the previous chapter, the Classic-LFA backup path was chosen whenever available, prioritizing it over the TI-LFA backup path. This decision was due to the fulfillment of the inequality condition, ensuring a straightforward backup path calculation.
In the current lab, however, the Classic-LFA inequality condition was not met. Consequently, a TI-LFA backup path was sought, and the following section provides a detailed explanation of this method.
The following topology diagram is relevant to the TI-LFA calculation explanation that follows.
Figure 7.2 – Single-segment FRR path calculation
The following explanation details the computation and selection of the primary path and backup path.
Primary path
The primary path from P2 to PE5 goes via P3, with the end-to-end path, cost of 30 (P2 - P3 - P4 - PE5), making it the shortest path.
Backup path
Moreover, the backup path is classified as TI-LFA...
