Verification
The following section verifies that the zero-segment FRR path is installed in the RIB, LFIB, and FIB.
Verifying max label support
The displayed output indicates that the XRv9K platform supports a maximum of three labels, and this holds true for the ASR9k platform as well:
RP/0/RP0/CPU0:P2#show isis interface Gi0/0/0/0 | i MPLS MPLS Max Label Stack: 3/3/10/10 (PRI/BKP/SRTE/SRAT) MPLS LDP Sync (L1/L2): Disabled/Disabled RP/0/RP0/CPU0:P2#
This implies that, in addition to the destination node label, the backup path can accommodate a maximum of two additional labels.
Verifying the zero-segment backup path
The following backup path output indicates the absence of any additional labels.
The primary path goes through P3, using the Gi0/0/0/0 interface. In the event of a failure on this link, the backup path reroutes through P7.
This is evident in the RIB, FIB, and LFIB.
