How to configure Queuing on Cisco 3560 and 3750 switch

[ReneMolenaar]

@szejiekoh

For both 3850 and 2960x series switches, besides the priority queue - does lower queue# equates to having higher priority ? (e.g. queue2 has higher priority then queue3)

These switches only have one priority queue, the other queues are served in (weighted) round robin so Q2 doesn’t have a higher priority than Q3.

@szejiekoh

For 2960x, are we able to assign/map the same CoS marking to more then 1 queue ? e.g. Cos 5 to queue 3 and 4 ?

You can assign a CoS/DSCP value to only one queue and threshold.

@szejiekoh

Does that means we have to either

a) mark a CoS value to all traffic in default-class + allocate/map this Cos value to just 1 queue
or
b) assign all possible CoS values to just 1 queue ?

I usually keep it simple and assign all CoS/DSCP values to one queue that you use for “best effort” traffic. This saves you the hassle of marking all traffic.

@szejiekoh

In your earlier response, you assign 5% bandwidth to Q3/Q4, what the point of doing so since everything else is assign to Q2 ?

You don’t really use these queues if you use Q1 as the priority queue and Q2 as the “best effort” queue but the problem is that you can’t assign 0 bandwidth or disable the other queues. You can assign the lowest possible values to these queues. I think 1% is possible.