MPLS Traceroute

[namratakadam]

if RSVP tunnel is down and not coming up. In that case, RSVP will generate RSVP error message and tear down tunnel. My question is in that case, will MPLS traceroute will show me where LSP is breaking. I think answer is no as all rsvp states will clear for that tunnell and there wont any be any label binding, mpls traceroute will fail at first hop. So we can use MPLS traceroute in RSVP only when tunnel is up ?? Can someone please confirm on this

[Sajid Ali]

Hi,

Please refer to below link, I hope it will help you.

http://www.cisco.com/c/en/us/td/docs/ios/12_0s/feature/guide/gslsppt.html#wp1086556

Don't forget to rate helpfull posts.

Sajid Ali Pathan

[Mohit Sahai]

Hello,

Yes you are correct. MPLS traceroute will show where the LSP is breaking.

"sh ip rsvp reservation detail" can help you to determine what you are looking for.

Please find the below document for RSVP troubleshooting..

http://www.cisco.com/c/en/us/td/docs/ios/12_0s/feature/guide/fsfrr24.html#wp1293096

--Pls dont forget to rate helpful posts--

Regards,

Mohit

[Akash Agrawal]

Hi,

When you do "mpls traceroute", it uses LDP label to reach the destination. Your LSP may be fine to tunnel destination, but still tunnel not coming up. To troubleshoot TE tunnel, first command you can use is "show mpls traffic-eng tunnels tunnel<number>". This command gives you point from where you are getting rsvp error message.

"show mpls traffic-eng topology" is also a good command to check if all links (supposed to be in the TE path as per IGP(in case of dynamic tunnel) or strict path) are available in TE topology database or not.

Regards,

Akash