[c-nsp] MQC-style marking on 3750 without mls qos?

[John Neiberger]

On Wed, Jun 27, 2012 at 8:07 PM, John Neiberger <jneiberger at gmail.com> wrote:
> I'm almost afraid to ask this question, but I have no shame. While
> troubleshooting an issue the other day that ultimately was
> demonstrated to be a queueing issue, Cisco TAC recommended that we
> disable mls qos since we didn't really need it. We don't have any
> queueing configured, so no big deal, right? Well, we have service
> policies attached to many interfaces on that 3750 that set DSCP
> markings. Those no longer seem to be working. We ran into the same
> problem on a different 3750, so we turned mls qos back on and it
> started working.
>
> It seems clear now, but is mls qos a requirement to do MQC-style DSCP marking?
>
> Thanks,
> John

Hmmm...answering my own question, it looks like the marking is
actually working! In a forehead-slapping moment, I just realized that
it's the command we use to check that isn't working. We use "show mls
qos interface xyz stat" to see the count of packets with various
markings. It makes sense that if mls qos is disabled, a "show mls qos"
command isn't going to work the way we want. Does that sound right?