show mpls forwarding-table exact-route label

sachin30720041 · ‎03-19-2022

Hello,

R7

/ \

R1---R2--R3--R4--R5 ----r6

\. /

R8

On R3

R3#show mpls forwarding-table 6.6.6.6
Local Outgoing Prefix Bytes interface Next Hop

label label
3002 4002 6.6.6.6/32 143864 Gi1 100.30.40.4
7002 6.6.6.6/32 1116 Gi3 100.30.70.7
8002 6.6.6.6/32 5862 Gi4 100.30.80.8

When I execute the following command on R3, it shows traffic from 1.1.1.1 to destination 6.6.6.6 will take the path through R7.

R3#show mpls forwarding-table exact-route label 3002 ipv4 source 1.1.1.1 destination 6.6.6.6

Local Outgoing Prefix Bytes Outgoing Next Hop
3002 7002 6.6.6.6/32 558 Gi3 100.30.70.7

But when I ping from 1.1.1.1 to 6.6.6.6, it takes the path through 8.8.8.8.

R1#traceroute 6.6.6.6 source 1.1.1.1
1 100.10.20.2 [MPLS: Label 2004 Exp 0] 590 msec * 560 msec
2 100.20.30.3 [MPLS: Label 3002 Exp 0] 579 msec 563 msec 555 msec
3 100.30.80.8 [MPLS: Label 8002 Exp 0] 551 msec 560 msec 558 msec
4 100.50.80.5 [MPLS: Label 5001 Exp 0] 444 msec 452 msec 449 msec
5 100.50.60.6 607 msec 567 msec 571 msec

I am not sure why traffic is taking the path through R8 while the exact-route command shows the traffic should go through R7.

Thanks,

Sachin

MHM Cisco World · ‎03-20-2022

Show ip route R6-Lo

you will see two path, and “ * “ beside the path routing use to forward Packet,

match this with mpls label use to forward traffic you will see it match path.

now I think it equal so path is 1:1 share and the path change in next Packet if cef is Packet not destination load share then you can see the correct path with label after Do more traceroute test.

check above point and send me result.

Amirmahdi.M · ‎07-07-2025

Hi @sachin30720041

Did you find out why this is happening?

I am having the exact same problem on asr903(15.4) and csr1000v(15.4).

Thanks

Amir

MHM Cisco World · ‎07-07-2025

Make new post please

MHM