Find which queue is dropping traffic cisco WS-C4928-10GE

[Bedevere Curry]

We have a WS-C4928-10GE and it has output drops. I suspect a configuration issue and I believe it's related to how they have it setup. 

However, I used to be able to run "show platform port-asic stats drop gx/x/x" on Cisco 3750 to see which queue was dropping.

The 4928 doesn't seem to support that command structure. 

I also tried other commands such as show qos, show policy map interface, etc.

How do we find which queue is dropping packets and which ones are not receiving traffic?

Thanks

We are running cat4500-entservices-mz.150-2.SG2.bin.

They don't have any policy configured on the interface but they have this configured:

interface GigabitEthernet1/2
 description pa01
 no switchport
 no ip address
 logging event link-status
 logging event trunk-status
 qos trust dscp
 snmp ifindex persist
 tx-queue 1
   bandwidth percent 30
 tx-queue 2
   bandwidth percent 30
 tx-queue 3
   bandwidth percent 30
   priority high
 tx-queue 4
   bandwidth percent 10
 channel-group 1 mode desirable
 spanning-tree bpduguard disable

We also have this configured:

qos map dscp 26 34 48 56 to tx-queue 1
qos map dscp 0 10 to tx-queue 4
qos map cos 1 to dscp 10 
qos map cos 2 to dscp 18 
qos map cos 3 to dscp 26 
qos map cos 4 to dscp 34 
qos map cos 5 to dscp 46 

GigabitEthernet1/2 is up, line protocol is up (connected) 
  Hardware is Gigabit Ethernet Port, address is f0f7.5510.a44f (bia f0f7.5510.a44f)
  Description: pa01
  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec, 
     reliability 255/255, txload 2/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 1000Mb/s, link type is auto, media type is No Gbic
  input flow-control is on, output flow-control is off
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:22, output never, output hang never
  Last clearing of "show interface" counters 1w1d
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 83906

[Markus Benz]

Hi,

did you try the following already?

sh mls qos int <interface> statistics

Regards,
Markus

[Bedevere Curry]

I haven't tried this I believe but I'll try it and let you know. thanks

[Bedevere Curry]

It doesn't support it.

[Steve Fuller]

On the Catalyst 4948 (which I believe is the same architecture as the 4928) it's as simple as show interface gi 1/2 counters detail.

If you want to look at the drops across any or several interfaces it's probably easier to use show interface counters detail and scroll through to the section with the queue drops.

Regards

[Bedevere Curry]

This just shows the different counters but does not show which queue is dropping the packets but thanks. 

[Steve Fuller · Accepted solution]

Doesn't it show as this then?

c4948-1#show interfaces counters detail | be Drop
Port       Tx-Drops-Queue-1  Tx-Drops-Queue-2 Tx-Drops-Queue-3  Tx-Drops-Queue-4
Gi1/1                     0                 0                0                 0
Gi1/2                     0                 0                0                 0
Gi1/3                     0                 0                0                 0
Gi1/4                     0                 0                0                 0
Gi1/5                     0                 0                0                 0
[snip]
Port       Dbl-Drops-Queue-1 Dbl-Drops-Queue-2 Dbl-Drops-Queue-3 Dbl-Drops-Queue-4
Gi1/1                      0                 0                 0                 0
Gi1/2                      0                 0                 0                 0
Gi1/3                      0                 0                 0                 0
Gi1/4                      0                 0                 0                 0
Gi1/5                      0                 0                 0                 0

Regards

[Bedevere Curry]

Let me double check and get back to you. Thanks

[Bedevere Curry]

I actually ran this before but overlooked it. Thank you very much and very appreciated!