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QoS in C6500 Sup2T

Hi Everyone,

I've got a C6504 Chassis with Sup2T with default qos configuration (auto qos default gobal command). When I use the "show platform qos ip" command I can see the following output:

QoS Summary [IPv4]: (* - shared aggregates, Mod - switch module, Sid - Switch Id, E - service instance)

                     (^ - class-copp keyword)

          Int  Sid Mod Dir  Class-map DSCP  Agg  Trust Fl      AgForward      AgPoliced

                                            Id         Id                            

-------------------------------------------------------------------------------

           CPP   1  1  In ^mcast-v4-    0    1     No  0              0              0

           CPP   1  1  In ^match-igm   48    2     No  0              0              0

......

           All   1  1   -    Default    0    0*    No  0 11780258945376              0

           All   1  4   -    Default    0    0*    No  0 28254137334635              0

1. ¿Why I can only see traffic with DSCP=0 if I know there are traffic with different DSCP markings passing through my C6504?

The interfaces are properly configured to trust cos markings and queue traffic

MLS#show queueing interface gi1/1/1

Interface GigabitEthernet1/1/1 queueing strategy:  Weighted Round-Robin

Port QoS is enabled globally

  Queueing on Gi1/1/1: Tx Enabled Rx Enabled

MLS#interface GigabitEthernet1/1/1

switchport

platform qos trust cos

2. Does the Sup2T with default qos configuration rewrite to 0 all DSCP markings by default?

Thank you in advance.

9 REPLIES
VIP Super Bronze

QoS in C6500 Sup2T

Hi,

The architecture of QOS with Sup-2T has completely changed form Sup-720.  I suggest going through this document and see what is default and what is not.  As far as I know, the default ports is to trust COS, DSCP marking.

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/white_paper_c11-652042.html#wp9000594

HTH

VIP Purple

Re: QoS in C6500 Sup2T

Yes, by default Sup2T will trust what ever QoS value (CoS for trunk port & DSCP for access port) of a incoming packet. So you do not want specific config to do so.

Below Ciscolive presentation will also help you (it is applicable for other switch platform as well) & keep it as a good reference.

BRKCRS-2501: Campus QoS Design—Simplified

HTH

Rasika

**** Pls rate all useful responses ****

Re: QoS in C6500 Sup2T

Hi Reza Sharifi and rasikanayanajith,

Thank you for your quicky responses. I had already read the links you suggest me but I'm still confused.

1. The first link says that QoS markings (CoS or DSCP) of the incoming packet are trusted by default. Ok

2. The document also says : "Queueing behavior identical to auto qos default. Policing/marking and DSCP/CoS rewrite is disabled". Then....It seems that DSCP/CoS markings are not changed by the sup2T. Ok

3. In my network I know there is traffic with different markings (EF,CS3,....)

Then ....why does the output of the command "show platform qos ip" show only traffic with DSCP=0?

QoS Summary [IPv4]: (* - shared aggregates, Mod - switch module, Sid - Switch Id, E - service instance)

                     (^ - class-copp keyword)

          Int  Sid Mod Dir  Class-map DSCP  Agg  Trust Fl      AgForward      AgPoliced

                                            Id         Id                           

-------------------------------------------------------------------------------

           CPP   1  1  In ^mcast-v4-    0    1     No  0              0              0

           CPP   1  1  In ^match-igm   48    2     No  0              0              0

......

           All   1  1   -    Default    0    0*    No  0 11780258945376              0

           All   1  4   -    Default   0    0*    No  0 28254137334635              0


VIP Purple

Re: QoS in C6500 Sup2T

What is the IOS version you are running & what is the line card in your chassis module  1 ?, the commands output seems different what I am seeing in one of my Sup2T.

CR01#sh ver | in Soft

Cisco IOS Software, s2t54 Software (s2t54-ADVENTERPRISEK9-M), Version 15.1(2)SY, RELEASE SOFTWARE (fc4)

CR01#show platform qos ip

   QoS is in queueing-only mode

CR01#show queueing interface g6/1

Interface GigabitEthernet6/1 queueing strategy:  Weighted Round-Robin

  Port QoS is enabled globally

  Queueing on Gi6/1: Tx Enabled Rx Enabled

Trust boundary disabled

  Trust state: trust DSCP

  Trust state in queueing: trust COS

  Extend trust state: not trusted [COS = 0]

  Default COS is 0

    Queueing Mode In Tx direction: mode-cos

    Transmit queues [type = 1p3q4t]:

    Queue Id    Scheduling  Num of thresholds

    -----------------------------------------

       01         WRR                 04

       02         WRR                 04

       03         WRR                 04

       04         Priority            01

    WRR bandwidth ratios:  100[queue 1] 150[queue 2] 200[queue 3]

    queue-limit ratios:     50[queue 1]  20[queue 2]  15[queue 3]  15[Pri Queue]

    queue tail-drop-thresholds

    --------------------------

    1     70[1] 100[2] 100[3] 100[4]

    2     70[1] 100[2] 100[3] 100[4]

    3     100[1] 100[2] 100[3] 100[4]

    queue random-detect-min-thresholds

    ----------------------------------

      1    40[1] 70[2] 70[3] 70[4]

      2    40[1] 70[2] 70[3] 70[4]

      3    70[1] 70[2] 70[3] 70[4]

    queue random-detect-max-thresholds

    ----------------------------------

      1    70[1] 100[2] 100[3] 100[4]

      2    70[1] 100[2] 100[3] 100[4]

      3    100[1] 100[2] 100[3] 100[4]

    WRED disabled queues:   

    queue thresh cos-map

    ---------------------------------------

    1     1      0

HTH

Rasika

**** Pls rate all useful responses ****

Re:QoS in C6500 Sup2T

Advanced ip services 15.0(1)SY2


Sent from Cisco Technical Support Android App

VIP Purple

Re: QoS in C6500 Sup2T

Hi

Do you have "platform qos queueing-only " in your configuration ? If not see the output with this command in your config.

If you look at this document it describe what this does "Queueing behavior identical to auto qos default. Policing/marking and DSCP/CoS rewrite is disabled."


http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/white_paper_c11-652042.html

HTH

Rasika

**** Pls rate all useful responses ****

Re: QoS in C6500 Sup2T

No, I don't have the "platform qos queueing-only " command in the running-config, just the "auto qos default" global command.

This is the output of the "show auto qos default ":

#show auto qos default

"auto qos default" is configured

Earl qos Enabled port qos Enabled queueing-only No

Re: QoS in C6500 Sup2T

Any update?

VIP Purple

Re: QoS in C6500 Sup2T

Hi,

Try configuring this command & see

platform qos queueing-only

See this post as well, I have replied with sample configuration that I got

https://supportforums.cisco.com/thread/2257458

HTH

Rasika

*** Pls rate all useful responses ****

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