[c-nsp] TTL not decrementing (MPLS, SXI, Sup720)

[Tim Durack]

On Wed, Jan 26, 2011 at 3:51 PM, Peter Rathlev <peter at rathlev.dk> wrote:

> On Wed, 2011-01-26 at 20:01 +0000, Phil Mayers wrote:
> > There are some funny behaviours w.r.t traceroute under PFC-3B and
> > earlier versions. Do you have a mix of PFC/DFC versions?
>
> Thanks for the tip. I looked more carefully at other devices and found
> out that at least one other device behaves like this. And it's also
> PFC3B with traffic exiting a CFC-equipped 6724-SFP, like this device.
>
> Other devices with PFC3C (i.e. VS-S720-10G) but similar CFC-equipped
> cards haven't got the problem. And PFC3B-equipped cards where the
> traffic arrives on DFC3C-equipped cards (WS-X6708-10GE) also haven't.
>
> > We see oddities routinely with penultimate hop popping and vrf aggregate
> > labels, including the same behaviour you're seeing. I believe it's a
> > hardware limitation.
>

I think I'm seeing something similar with a few 6504/SUP720-3BXL/6724-CFC
running 12.2(33)SXI3.

Traceroutes crossing these units in the global table timeout. Works fine in
a VRF.

Can't mpls ping/traceroute from these units in the global table. Works fine
in a VRF.

This makes troubleshooting unnecessarily difficult. Anyone found Cisco
documentation explaining this behavior?

-- 
Tim:>