[c-nsp] DSCP and Queue counters on 7600s

[Tony]

In the past I have used a qos policy that "does nothing" to monitor the traffic. It at least lets me see the number of bytes that matched each DSCP, even if not being able to see in real time what is in the queues. The one below only shows CS3 traffic, but you would just build it up to add the other things you need to monitor. The "set" statement doesn't really do anything, because the packets should already be marked with what they are being set to, it's just there to force the box to count the packets because it has to do something on them, so "touches" the packet and forces a counter increment. Unfortunately it doesn't show packet count (just bytes and rate in bps). You could apply the same policy in the outbound direction to show similar info.


class-map match-any class-dscp24 match ip dscp cs3 
policy-map monitor-qos class class-dscp24  set ip dscp 24 class class-default  set ip dscp 0
int gig7/16 service-policy input monitor-qos
#show policy-map int gig7/16 GigabitEthernet7/16
  Service-policy input: monitor-qos
    class-map: class-dscp24 (match-any)      Match: ip dscp cs3 (24)      set dscp 24:      Earl in slot 5 :        0 bytes        5 minute offered rate 0 bps        aggregate-forwarded 0 bytes
    class-map: class-default (match-any)      Match: any      set dscp 0:      Earl in slot 5 :        536 bytes        5 minute offered rate 32 bps        aggregate-forwarded 536 bytes

So you can see that since I applied the policy there has been 536 bytes of traffic inbound that matched the default class (this interface is used for testing stuff, so doesn't really have anything much attached to it).

Two other options come to mind:
1. SPAN/mirror the port and hook something useful up to see what is happening (eg. tcpdump, wireshark, etc).2. I have never used it, but there is a thing called "PFC QoS statistics data export" which MIGHT do what you want (purely based on what the description of it says).


Best of luck,Tony.

      From: James Bensley <jwbensley at gmail.com>
 To: "cisco-nsp at puck.nether.net" <cisco-nsp at puck.nether.net> 
 Sent: Monday, 14 December 2015, 19:31
 Subject: Re: [c-nsp] DSCP and Queue counters on 7600s
   
On 13 December 2015 at 18:19, Lukas Tribus <luky-37 at hotmail.com> wrote:
>
>> Hi All,
>>
>> Got some 7600s with RSP720-3CXL-10G and LAN cards (CFC, no DFCs) and
>> I'm "trying" to run QoS on them.
>>
>> Does anyone know of a command to show the number of packets that
>> entered each queue/show some queue counters?
>
> Afaik this should be it:
> show queueing interface <intfname>

Sadly that command isn't supported:

abr1#show q?
qbm

"show mls qos queuing int te3/1" shows me the MLS QoS configuration
such queue depths, bandwidth allocation, thresholds etc and the total
number of drop packets per CoS marking/queue. It doesn't show counters
per queue.

"show counters interface te3/1" is the same, it only shows lost
packets tx/rx, so if I use multiple instances of a basic traffic
generator like iPerf with different DSCP markings on each flow I don't
actually know which queues the packets are going into (so if there is
unexpected drops or traffic isn't being dropped etc, it's just guess
work).

This seems like a major floor to me. In the TAC case I have open the
engineer is saying he doesn't believe there is such a command.
Disappointing.

Cheers,
James.


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