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

[John Neiberger]

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