qos 3560

Scott Morris swm at emanon.com
Thu Nov 12 08:40:54 CST 2009


Look at "show mls qos map" to see the defaults that may be rewriting
your information depending on trust (or non-trust) mechanisms you have
configured.

If you trust CoS, a frame received with cos5 and dscp46 will get
rewritten to dscp 40 with default maps...

"show mls qos interface (intf)" is also good to see status.

Scott



Bogdan wrote:
> hello
>
> indeed, a fellow nanoger gave me this hint.
>
> 1. i had to enable mls qos globally in "network" switches
> 2. set the mls qos trust dscp on the uplinks (ingress port)
>
>
> thanks
>
> ps thanks to andrey.gordon too :)
>
>
>
>
>
> On 11/12/2009 03:21 PM, Brian Feeny wrote:
>   
>> You should make sure that any links that go between devices have trust
>> set.  In your case if your doing DSCP,
>> then make sure each link that goes between devices which must carry
>> tagged packets have trust dscp set.
>>
>> Brian
>>
>> On Nov 12, 2009, at 5:11 AM, Bogdan wrote:
>>
>>     
>>> hello
>>>
>>> i am playing with qos on some devices
>>> - cisco 3560
>>> - cisco 7609
>>> and i have some things that i don't seem to understand.
>>>
>>> 1. in 3560, i enable mls qos, on the ingress port applyed policy map,
>>> classify the packets with acl, mark, all good. on the egress ports i use
>>> srr-queue with shape/share, everything is fine, it is working.
>>>
>>> http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_20_se/configuration/guide/swqos.html#wp1028614
>>>
>>>
>>>
>>> 2. reset to defaults the 3560
>>> in 7606 i pick up a vlan, and apply a policy-map and set dscp 40 on
>>> egress of that vlan
>>> 3560 in uplinked in 7609
>>> in 3560 i can see the "marked" packets, and i have matches on the dscp
>>> set earlier (sh mls qos int xx stat).
>>> the problem is: when i apply the srr-queue in 3560 on egress (towards
>>> the test port), it does not work.
>>> if i enable mls qos on 3560, i cannot match anymore the dscp 40 from the
>>> 7609
>>>
>>> is it normal? do i have to apply the qos stuff (point1) on all switches
>>> i want qos on? i mean, i cannot set dscp in one "core" device and use
>>> that in the whole network ?
>>>
>>>
>>> thanks
>>>
>>>
>>>       
>>     
>
>
>
>
>   




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