Use of Show mls qos ip command in 6500

[aacole]

I'm trying to get some output from the `sh mls qos ip' to show dscp statistics on a 6509 switch with Sup 720.

The 6509 I'm working on has mls qos enabled, and trust dscp on the interfaces that the packets traverse. I've got a PC at each end with wireshark and am using Iperf to generate packets marked with dscp ef. Wireshark shows packets (in one direction) are marked with ef at both ends, so I know the marked packets are going through the switch.

But, when I run the command all I get is output for packets with default dscp:

sh mls qos ip
QoS Summary [IPv4]:      (* - shared aggregates, Mod - switch module)

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

           All  3   -    Default    0    0*    No  0         378336              0
           All  5   -    Default    0    0*    No  0      727690656              0

Is there something else I need to enable so the command can pick up the ef marked packets?

[Fabienne Stephanoff]

Hello,

You can try the command "show mls qos last mod ". This will at least provide you with the marking of the last qos packet. Just repeat the command as needed.

> 6500#sh mls qos last mod 9
> QoS last packet policing information:
>    
> ---------------------------------------------------------------------
>     Packet was transmitted
>     Packet L3 Prot: 0, packet length: 64, dont_plc: No
>     Input COS: 0, TOS/DSCP: 0x0/0
>     Output TOS/DSCP: 0x0/0[unchanged]   Output COS: 0[unchanged]
>     Output MPLS EXP (if outgoing packet is MPLS): 0

Do you have a policy applied? If so and depending on your class-map configuration you may be able to use "show policy-map int ".

Hope this helps.

Fabienne.

[Shashank Singh]

"show mls qos ip" command shows marking of a packet with respect to the class-map it hits. With no class-map configured, packet hits the default class map for which marking displayed is always 0.

Only if you set a service-policy on the interface for marking the packet, correct dscp value shows up. For example:

24-12-6509-1#sh mls qos ip

QoS Summary [IPv4]:      (* - shared aggregates, Mod - switch module)

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

                                       Id         Id

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

         Gi2/2  5  In       test   46    2     No  0              0

0

         Gi7/1  5  In       af21   18    1     No  0   479595819498

0

           All  1   -    Default    0    0*    No  0     1439834472

0

           All  5   -    Default    0    0*    No  0   480680196849

0

           All  6   -    Default    0    0*    No  0      237327364

6509-1#sh run int gi7/1

interface GigabitEthernet7/1

ip address 172.16.55.73 255.255.255.252

service-policy input set-dscp

end

6509-1#sh policy-map set-dscp

  Policy Map set-dscp

    Class af21

      set dscp af21

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