[c-nsp] Packet drops on MPLS xconnect

[Tom Storey]

Hi all,

I am experiencing packet drops in the tx direction of an MPLS based xconnect.

The xconnect is between a 7304 NPE-G100 and a 7206VXR NPE-G1, and only
seems to be an issue with tx from the 7304. rx on the 7304 is fine, and tx
and rx on the 7206 are also fine.

Moving the xconnect from the 7304 onto another 7206VXR NPE-G1 resolves the
issue.

Ive tried an IOS upgrade, reboot, rebuild of the xconnect, but to no avail.

Ive also tried turning on various debug commands but wasnt able to obtain
any usefil hints as to what the problem is.

Here is part of the output of a "show mpls l2 vc detail" for the xconnect:

  VC statistics:
    packet totals: receive 545, send 485
    byte totals:   receive 72955, send 61850
    packet drops:  receive 0, seq error 0, send 60

This was captured after the reboot so there isnt much happening, but you
can see there are tx packet drops.

Ive used various debug commands to try and get something to work on,
including the following:

debug mpls l2 vc event
debug mpls l2 vc fsm
debug mpls l2transport signaling message
debug mpls l2 packet error

I was hoping the last one would reveal something interesting, but I only
seemed to get output from the first 1-2 commands.

The xconnect establishes with no problems, and it will stay up, it just
seems to be dropping packets for some reason.

Is anyone familiar with the causes of these types of issues and what else
can be looked at/debugged and how to resolve it?

Thanks,
Tom