[c-nsp] Multicast issues on 7600s with WS-6748-sfp blades

[Asbjorn Hojmark - Lists]

On Thu, 29 Jul 2010 08:29:18 -0400, you wrote:

> I have seen some pretty low level problems with multicast packets
> being dropped on the floor by the hardware forwarded on 67xx
> linecards. The bug seems to appear when changes that effect the asic
> (turning on "mls qos" for example). Resetting the sup engine doesn't
> resolve it. Everything looks good at the CEF/mfib level, and all
> counters show the packet count increasing, but the packets never get
> forwarded out of the linecard.

Sounds a bit like CSCtc24959, which I saw with a couple of customers.
It was typically seen on changes to topology (i.e. rerouting).

Flipping the replication mode:
  mls ip multicast replication-mode ingress
  no mls ip multicast replication-mode ingress [1]
causes reprogramming of the hardware, which fixed the problem without
having to reset the whole blade. Note that it *is* traffic-affecting
for all active multicast flows.

CSCtc24959 is fixed in SRD4 and will not be integrated in earlier
releases, or so I was told.

HTH,
-A
[1] Or the other way round if you use ingress replication