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New Member

QOS Table Maps (Cisco 6500 IOS 15)

I am trying to work out how I can see if the table maps are used during qos on my 6500.

So on interface

1/2/42 i have the following inbound policy map

policy-map QOS-Markings

  class Lync-ef

   set dscp ef

  class Lync-af41

   set dscp af41

  class class-default

This matches packets via some ACL's and marks them with a DSCP value, the policy map only allows me to use DSCP or COS, so I chose DSCP as another router further up the line is already set to more finaly policy DSCP in packets.

then on an outboud inter face G1/2/41 I have

policy-map type lan-queuing Comp-Out

  class DSCP-ef

    priority

  class DSCP-af40

    bandwidth remaining percent 30

    queue-buffers ratio 15

    random-detect cos-based

  class DSCP-af30

    bandwidth remaining percent 10

    queue-buffers ratio 20

    random-detect cos-based

  class class-default

    queue-buffers ratio 20

    random-detect cos-based

Ignore the class names, the classes actuly look like this.

Class Map type lan-queuing match-any DSCP-ef (id 40)

   Match cos  5

Class Map type lan-queuing match-any DSCP-af40 (id 41)

   Match cos  4

Class Map type lan-queuing match-any DSCP-af30 (id 42)

   Match cos  3  6  7

so I am matching on COS as the queuing on the switch line card only allows based on this, I have the standard default table maps for DSCP - COS  globably configured.

but my question is at what point do the table maps come in to play, and how can i see the COS markings of the packets to see if they are getting queued correctly? I can see with a packet capture that the the DSCP is marked correctly, but the COS field is not shown as there is n0 802.1q tagging once the packet leaves the switch.

So how do I show what packets are going in to which queue on the outbound interface?

I hope you can see waht I want to achive, which is have packets comming and getting marked with the DSCP values, but queued on this switch by the COS value. But I dont see any way of using show commands to see if this it happening or is I need furtehr commands to make it happen.

Cheers

1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Blue

Re: QOS Table Maps (Cisco 6500 IOS 15)

Aaron  

Yes, apologies but i assumed the second to last table in the output showing "Packets dropped on Transmit:" actually showed packets dropped but also the number of packets seen in the queues but now i am not so sure.

Unfortunately i know of no other command that shows anything like this. 6500 QOS, as with a lot of hardware switches can be very difficult to actually see what the switch is doing.

All i can say is that if you matching on DSCP on ingress then that DSCP value will be used as the internal DSCP value of the switch and, as long as you are not doing any DSCP mutation, it is this value together with the dscp-cos map that is used to derive the actual CoS value of the packet.

Jon

5 REPLIES
Hall of Fame Super Blue

Re: QOS Table Maps (Cisco 6500 IOS 15)

Aaron

Try this command -

show queueing interface gi1/2/41 detailed

The switch uses an internal DCSP value as the packet moves through it. When it comes to outbound queueing the dscp-cos map is used to derive a CoS value from the internal DCSP value.

Jon

Hall of Fame Super Blue

Re: QOS Table Maps (Cisco 6500 IOS 15)

Aaron

In addition to previous post have you checked your maps ie. "sh mls qos maps" to make sure the mapping are what you expect, because they may need modifying.

Jon

Highlighted
New Member

Re: QOS Table Maps (Cisco 6500 IOS 15)

Hi,

so yes the show platofrom qos maps show as

discard-class-cos-map:                         (discard-class= d1d2)

     d1 :  d2 0  1  2  3  4  5  6  7  8  9

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

      0 :    00 00 00 00 00 00 00 00 01 01

      1 :    01 01 01 01 01 01 02 02 02 02

      2 :    02 02 02 02 03 03 03 03 03 03

      3 :    03 03 04 04 04 04 04 04 04 04

      4 :    05 05 05 05 05 05 05 05 06 06

      5 :    06 06 06 06 06 06 07 07 07 07

      6 :    07 07 07 07

with other maps omitted

and the show queueing  int g1/2/41 detail shows

ASH_6506#sh queueing int g1/2/41 detailed

Interface GigabitEthernet1/2/41 queueing strategy:  Weighted Round-Robin

  Port QoS is disabled globally

  Queueing on Gi1/2/41: Tx Enabled Rx Disabled

Trust boundary disabled

  Trust state: trust DSCP

  Trust state in queueing: trust COS

  Extend trust state: not trusted [COS = 0]

  Default COS is 0

    Class-map to Queue in Tx direction

    Class-map           Queue Id

    ----------------------------

    DSCP-ef                   4

    DSCP-af40                 3

    DSCP-af30                 2

    class-default             1

    Queueing Mode In Tx direction: mode-cos

    Transmit queues [type = 1p3q8t]:

    Queue Id    Scheduling  Num of thresholds

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

       01         WRR                 08

       02         WRR                 08

       03         WRR                 08

       04         Priority            01

    WRR bandwidth ratios:   60[queue 1]  10[queue 2]  30[queue 3]

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

    queue tail-drop-thresholds

    --------------------------

    1     100[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8]

    2     100[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8]

    3     100[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8]

    queue random-detect-min-thresholds

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

      1    40[1] 70[2] 70[3] 70[4] 70[5] 70[6] 70[7] 100[8]

      2    40[1] 70[2] 70[3] 70[4] 70[5] 70[6] 70[7] 100[8]

      3    70[1] 70[2] 70[3] 70[4] 70[5] 70[6] 70[7] 100[8]

    queue random-detect-max-thresholds

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

      1    70[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8]

      2    70[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8]

      3    100[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8]

    WRED disabled queues:   

    queue thresh cos-map

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

    1     1     

    1     2     

    1     3     

    1     4     

    1     5     

    1     6     

    1     7     

    1     8      0 1 2

    2     1     

    2     2     

    2     3     

    2     4     

    2     5     

    2     6     

    2     7     

    2     8      3 6 7

    3     1     

    3     2     

    3     3     

    3     4     

    3     5     

    3     6     

    3     7     

    3     8      4

    4     1      5

    Queueing Mode In Rx direction: mode-cos

    Receive queues [type = 1q8t]:

    Queue Id    Scheduling  Num of thresholds

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

       01         WRR                 08

    WRR bandwidth ratios:  100[queue 1]

    queue-limit ratios:    100[queue 1]

    queue tail-drop-thresholds

    --------------------------

    1     100[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8]

    queue thresh cos-map

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

    1     1      0 1 2 3 4 5 6 7

    1     2     

    1     3     

    1     4     

    1     5     

    1     6     

    1     7     

    1     8     

  Packets dropped on Transmit:

    BPDU packets:  0

    que           dropped        30-s bytes        peak bytes    5-mins avg bps          peak bps  [cos-map]

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

    1               29226                 0                 0                 0                 0   [0 1 2 ]

    2                   0                 0                 0                 0                 0   [3 6 7 ]

    3                   0                 0                 0                 0                 0   [4 ]

    4                   0                 0                 0                 0                 0   [5 ]

  Packets dropped on Receive:

    BPDU packets:  0

    que           dropped        30-s bytes        peak bytes    5-mins avg bps          peak bps  [cos-map]

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

    1                2050                 0                 0                 0                 0   [0 1 2 3 4 5 6 7 ]

But I dont see how I can get to see that different queues are actuly seeing traffic, from the output here all traffic could be getting put in to queue 1. I assume that queuing is only active during high port uterlisation, It would be nice if there was a simple way to do some thing like below

#show platform qos traffic int g1/2/41 [input/outut] [COS/DSCP/Pres].

and it would give the current statues of the frames/packets across the link like this

COS value,   Packets,     bytes

1                    4500          14600000

2                            

3                             

4                    2300          120000

5                    1500          640000

6                    200            23000

7

This would make checking packet marking more stright forward, as I like you say thought that it will map the values as needed, but there is no show commands to see this is happening, and the show queuing doesnt really help.

Hall of Fame Super Blue

Re: QOS Table Maps (Cisco 6500 IOS 15)

Aaron  

Yes, apologies but i assumed the second to last table in the output showing "Packets dropped on Transmit:" actually showed packets dropped but also the number of packets seen in the queues but now i am not so sure.

Unfortunately i know of no other command that shows anything like this. 6500 QOS, as with a lot of hardware switches can be very difficult to actually see what the switch is doing.

All i can say is that if you matching on DSCP on ingress then that DSCP value will be used as the internal DSCP value of the switch and, as long as you are not doing any DSCP mutation, it is this value together with the dscp-cos map that is used to derive the actual CoS value of the packet.

Jon

New Member

Re: QOS Table Maps (Cisco 6500 IOS 15)

I think once queuing kicks in it does show the traffic. but I think i read it only kicks in queuing once a link is conjested, as I can see it droppioing packets but only in Queue 1 (which if it was working is exactly what I want to see )

From what you say I have it correct, but unless the link is conjested I wont see any values seems a litle bit of an over site that its not possible to clearly check its running correctly. Supose I will jsut have to generate a lot of traffic and see what happens.

cheers for the help.

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