LDP/TDP breaks at core routers

[maher]

Hi there,

I'm still new with MPLS/VPN.However, I would like to ask if there is a break in LDP/TDP at core router(P), which sometimes due to misconfiguration like not enabling ip cef, tag-switching ip at each interface,

in terms routing mechanism and update how does on each PE routers detect the break?

For a normal IP packet, I presummed the traffic will flow but if MPLS packet? Perhaps a routing issue?

thanks in advance.

maher

[adityakaul · Accepted solution]

It will lead to LSP failure as there won't be any LDP label(outer label) to forward the traffic to the egress PE.

Pls have look at the url below.

http://www.cisco.com/warp/public/105/troubleshoot_mpls_vpn.html

[Harold Ritter · Accepted solution]

Because of the IOS LDP implementation (Independent LSP Control as opposed to ordered LSP control), it might not always be possible to troubleshoot the issue solely by looking at the ingress PE. The ingress PE might have an assigned IGP label but that LSP might be imcomplete (not end to end). Tools like LSP ping and traceroute are a great help when trying to troubleshoot such cases. LSP ping/traceroute have been integrated in 12.0(27)

For more information on this feature, refer to the following URL:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1829/products_feature_guide09186a00801eb054.html

Hope this helps,

[Harold Ritter]

Oops, I meant 12.0(27)S.

[maher]

Thanks for the info and link

maher