MPLS : NOT ABLE TO OPEN SOME SITE

[rusky12us]

HI

we have 7200 series router having mpls connectivity , we are able to open some sites but not able to open the other. what may be the possible cause , we have change the router , pc, also but the problem is same , and when we trace and ping the site which are not opening , the trace and ping are normal , pls suggest

[Harold Ritter]

It might be an MTU issue. Could you try pinging the site that you are having issues with using a 1500 bytes packet and disallowing fragmentation. You can do that with an extended ping on the router or you can also do it from the work station. Try the same thing with the site that does work. You should see right away if this is the issue.

Hope this helps,

[Sanjeewa Alahakone]

Hopefully following method would help you to find the problem.

1. This was a working configuration

Then look for what has been changed

2. This is a new configuration - check what is different to working VPNs

Otherwise, define the problem

Such as; unable to communicate from ingress PE or egress PE

Break the troubleshooting to Control Plane (CP) and Forwarding plane a.k.a data plane

CP - troubleshooting

- check the PE/CE connectivity by PING VRF xx.xx.xx.xx

- check you have route to CE, local network

- check bgp has assigned a label for the remote network

- check label is correct in ingress PE

- check VPN routes are imported

Forwarding plane

- check MTU as suggested

- check CEF table is correct

- check PE-CE link CEF enabled

- Check for the untagged LSP

Hope this helps

Sanjeewa Alahakone

APT - TAC