[c-nsp] Label still appearing in traceroute after disabling ttl propagation

John Neiberger jneiberger at gmail.com
Tue Jul 30 13:37:50 EDT 2013

I think either we're just doing something wrong or perhaps we're running
into a bug. I did find this one, which sounds similar:


I'm not sure if that is fixed in 4.1.0 or not.

On Tue, Jul 30, 2013 at 11:01 AM, John Neiberger <jneiberger at gmail.com>wrote:

> W
> e're running into an interesting problem. We have a simple lab setup like
> this:
> CE1 -- PE1 --- P1 --- P2 --- PE2 --- CE2
> We have "mpls ip-ttl-propagate disable" on all PE and P routers, but if we
> trace from CE1 to CE2, we still see an MPLS label coming from the PE2
> router. If we trace CE2 to CE1, we see a label on the hop from P1 to PE1.
> If we have ttl propagation completely disabled, why would we still see the
> label and P-to-PE link in the path?
> All P and PE routers are IOS XR running 4.1.0.
> Thanks,
> John

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