[c-nsp] How to find the root cause of packet loss

[Peter Rathlev]

On Tue, 2010-06-22 at 12:31 +0200, LM wrote:
> Is there any command inside the switch to determine a possible packet 
> loss?, more than the error counters under "sh int", I am curious about
> the ASIC values and buffer issues.

The 2970 has the "show platform pm if-numbers" and "show platform
port-asic stats drop asic <X>" to give you that kind of information,
just like the 3560/3750.

The rest of this (long) mail is the output from the switch a switch that
has dropped 12 frames on Gi0/1.

Switch#show platform pm if-numbers

interface gid  gpn  lpn  port slot unit slun port-type lpn-idb gpn-idb
---------------------------------------------------------------------------------
Gi0/1     1    1    1    1/3  1    1    1    local     Yes     Yes
Gi0/2     2    2    2    1/2  1    2    2    local     Yes     Yes
Gi0/3     3    3    3    1/0  1    3    3    local     Yes     Yes
Gi0/4     4    4    4    1/1  1    4    4    local     Yes     Yes
Gi0/5     5    5    5    2/3  1    5    5    local     Yes     Yes
Gi0/6     6    6    6    2/2  1    6    6    local     Yes     Yes
Gi0/7     7    7    7    2/0  1    7    7    local     Yes     Yes
Gi0/8     8    8    8    2/1  1    8    8    local     Yes     Yes
Gi0/9     9    9    9    0/3  1    9    9    local     Yes     Yes
Gi0/10    10   10   10   0/2  1    10   10   local     Yes     Yes
Gi0/11    11   11   11   0/0  1    11   11   local     Yes     Yes
Gi0/12    12   12   12   0/1  1    12   12   local     Yes     Yes
Gi0/13    13   13   13   3/3  1    13   13   local     Yes     Yes
[...]

Switch#sh platform port-asic stats drop asic 1

Port-asic Port Drop Statistics - Summary
========================================
  RxQueue 0 Drop Stats: 0
  RxQueue 1 Drop Stats: 0
  RxQueue 2 Drop Stats: 0
  RxQueue 3 Drop Stats: 0

  Port  0 TxQueue Drop Stats: 0
  Port  1 TxQueue Drop Stats: 0
  Port  2 TxQueue Drop Stats: 0
  Port  3 TxQueue Drop Stats: 12

  Supervisor TxQueue Drop Statistics
    Queue  0: 0
    Queue  1: 0
    Queue  2: 0
    Queue  3: 0
    Queue  4: 0
    Queue  5: 0
    Queue  6: 0
    Queue  7: 0
    Queue  8: 0
    Queue  9: 0
    Queue 10: 0
    Queue 11: 0
    Queue 12: 0
    Queue 13: 0
    Queue 14: 0
    Queue 15: 0

Port-asic Port Drop Statistics - Details
========================================
  RxQueue Drop Statistics
    Queue 0
    Weight 0 Frames: 0
    Weight 1 Frames: 0
    Weight 2 Frames: 0
    Queue 1
    Weight 0 Frames: 0
    Weight 1 Frames: 0
    Weight 2 Frames: 0
    Queue 2
    Weight 0 Frames: 0
    Weight 1 Frames: 0
    Weight 2 Frames: 0
    Queue 3
    Weight 0 Frames: 0
    Weight 1 Frames: 0
    Weight 2 Frames: 0

  Port 0 TxQueue Drop Statistics
    Queue 0
      Weight 0 Frames 0
      Weight 1 Frames 0
      Weight 2 Frames 0
    Queue 1
      Weight 0 Frames 0
      Weight 1 Frames 0
      Weight 2 Frames 0
    Queue 2
      Weight 0 Frames 0
      Weight 1 Frames 0
      Weight 2 Frames 0
    Queue 3
      Weight 0 Frames 0
      Weight 1 Frames 0
      Weight 2 Frames 0

  Port 1 TxQueue Drop Statistics
    Queue 0
      Weight 0 Frames 0
      Weight 1 Frames 0
      Weight 2 Frames 0
    Queue 1
      Weight 0 Frames 0
      Weight 1 Frames 0
      Weight 2 Frames 0
    Queue 2
      Weight 0 Frames 0
      Weight 1 Frames 0
      Weight 2 Frames 0
    Queue 3
      Weight 0 Frames 0
      Weight 1 Frames 0
      Weight 2 Frames 0

  Port 2 TxQueue Drop Statistics
    Queue 0
      Weight 0 Frames 0
      Weight 1 Frames 0
      Weight 2 Frames 0
    Queue 1
      Weight 0 Frames 0
      Weight 1 Frames 0
      Weight 2 Frames 0
    Queue 2
      Weight 0 Frames 0
      Weight 1 Frames 0
      Weight 2 Frames 0
    Queue 3
      Weight 0 Frames 0
      Weight 1 Frames 0
      Weight 2 Frames 0

  Port 3 TxQueue Drop Statistics
    Queue 0
      Weight 0 Frames 0
      Weight 1 Frames 0
      Weight 2 Frames 0
    Queue 1
      Weight 0 Frames 0
      Weight 1 Frames 0
      Weight 2 Frames 0
    Queue 2
      Weight 0 Frames 0
      Weight 1 Frames 0
      Weight 2 Frames 0
    Queue 3
      Weight 0 Frames 0
      Weight 1 Frames 0
      Weight 2 Frames 12
  Supervisor TxQueue Drop Statistics
    Queue  0: 0
    Queue  1: 0
    Queue  2: 0
    Queue  3: 0
    Queue  4: 0
    Queue  5: 0
    Queue  6: 0
    Queue  7: 0
    Queue  8: 0
    Queue  9: 0
    Queue 10: 0
    Queue 11: 0
    Queue 12: 0
    Queue 13: 0
    Queue 14: 0
    Queue 15: 0
Switch#sh ver
Cisco IOS Software, C2970 Software (C2970-LANBASEK9-M), Version 12.2(25)SEC2, RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2005 by Cisco Systems, Inc.
Compiled Wed 31-Aug-05 10:12 by antonino

ROM: Bootstrap program is C2970 boot loader
BOOTLDR: C2970 Boot Loader (C2970-HBOOT-M) Version 12.1(14r)EA1a, RELEASE SOFTWARE (fc1)

 Switch uptime is 22 minutes
System returned to ROM by power-on
System image file is "flash:/c2970-lanbasek9-mz.122-25.SEC2.bin"
[...]

HTH.

-- 
Peter