Verifying the backup path traceroute

The essential components necessary for the nil-FEC traceroute, as derived from the RIB, FIB, or LFIB, are as follows:

• Label stack (top to bottom): 16008 24019 16005, directing traffic to P8, then P8–P4, and finally, PE5.
• Outgoing interface: GigabitEthernet0/0/0/1, toward P6.
• Next-hop IP address of the outgoing interface: 26.0.0.6, to P6.

Note

The Adjacency-SID label is allocated from the dynamic label space, so each iteration of this lab might display a different label for everyone.

The nil-fec traceroute for the backup path from P2 to PE5, as per the preceding information, is displayed as follows:

RP/0/RP0/CPU0:P2#traceroute sr-mpls nil-fec labels 16008,24019,16005 output interface GigabitEthernet0/0/0/1 nexthop 26.0.0.6
Tracing MPLS Label Switched Path with Nil FEC with labels [16008,24019,16005], timeout is 2 seconds
Codes: '!' - success, 'Q' - request not sent, '.' - timeout...