Query on Catalyst 3750 outdiscards

pokwan · ‎11-27-2013

Hi,

I have seen outdiscard errors on almost all the interfaces on a 3750 switch, The other counters are fine. Please see example below

Port Align-Err FCS-Err Xmit-Err Rcv-Err UnderSize OutDiscards

Fa1/0/1 0 0 0 0 0 1973

Fa1/0/2 0 0 0 0 0 2510

Fa1/0/3 0 0 0 0 0 16

Fa1/0/4 0 0 0 0 0 2537

Fa1/0/5 0 0 0 0 0 60

Fa1/0/6 0 0 0 0 0 5234

The version on the switch is

Version 12.2(44)SE5

Is this a cosmetic bug or something else?

TIA.

PF

Leo Laohoo · ‎11-27-2013

Post the output to the command "sh controller ether ".

pokwan · ‎11-27-2013

Leo,

Thanks for you reply. Here the output on one of the interfaces.

Thanks.

PF

sh controllers ethernet-controller fa1/0/5

     Transmit FastEthernet1/0/5               Receive
   3168669192 Bytes                       3312837171 Bytes
     12135059 Unicast frames                10358331 Unicast frames
     12326652 Multicast frames                133105 Multicast frames
      9397857 Broadcast frames                 12765 Broadcast frames
            0 Too old frames              3281774438 Unicast bytes
            0 Deferred frames               26758791 Multicast bytes
            0 MTU exceeded frames            1632366 Broadcast bytes
            0 1 collision frames                   0 Alignment errors
            0 2 collision frames                   0 FCS errors
            0 3 collision frames                   0 Oversize frames
            0 4 collision frames                   0 Undersize frames
            0 5 collision frames                   0 Collision fragments
            0 6 collision frames
            0 7 collision frames             3798483 Minimum size frames
            0 8 collision frames              493527 65 to 127 byte frames
            0 9 collision frames             2517952 128 to 255 byte frames
            0 10 collision frames            2374205 256 to 511 byte frames
            0 11 collision frames             359315 512 to 1023 byte frames
            0 12 collision frames             960719 1024 to 1518 byte frames
            0 13 collision frames                  0 Overrun frames
            0 14 collision frames                  0 Pause frames
            0 15 collision frames
            0 Excessive collisions                 0 Symbol error frames
            0 Late collisions                      0 Invalid frames, too large
            0 VLAN discard frames                  0 Valid frames, too large
            0 Excess defer frames                  0 Invalid frames, too small
      5875378 64 byte frames                       0 Valid frames, too small
      7919321 127 byte frames
      8549995 255 byte frames                      0 Too old frames
      6586526 511 byte frames                      0 Valid oversize frames
       580647 1023 byte frames                     0 System FCS error frames
      4347701 1518 byte frames                     0 RxPortFifoFull drop frame
            0 Too large frames
            0 Good (1 coll) frames
            0 Good (>1 coll) frames

daniel.dib · ‎11-27-2013

You have a Gigabit uplink? The buffers on the Catalysts are quite small so when using different speeds you can see drops. Also if there is a lot of microbursting. Can you have a look at the show platform port-asic as well.

Daniel Dib
CCIE #37149

Daniel Dib
CCIE #37149
CCDE #20160011

Please rate helpful posts.

pokwan · ‎11-28-2013

Daniel,

Thanks for your reply.

Yes we do have GIgabit uplink. The following is sh platform port-asic stats drop. By the way, we have other Gig switches (WS-C3750E-48TD, version 12.2(58)SE2, no QoS ) with the same issue.

sh platform port-asic stats drop

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: 2508
Port 3 TxQueue Drop Stats: 904
Port 4 TxQueue Drop Stats: 9276
Port 5 TxQueue Drop Stats: 4902
Port 6 TxQueue Drop Stats: 3013
Port 7 TxQueue Drop Stats: 6004
Port 8 TxQueue Drop Stats: 1038
Port 9 TxQueue Drop Stats: 1420
Port 10 TxQueue Drop Stats: 3128
Port 11 TxQueue Drop Stats: 2200
Port 12 TxQueue Drop Stats: 4582
Port 13 TxQueue Drop Stats: 2296
Port 14 TxQueue Drop Stats: 4809
Port 15 TxQueue Drop Stats: 1684
Port 16 TxQueue Drop Stats: 8599
Port 17 TxQueue Drop Stats: 869
Port 18 TxQueue Drop Stats: 9848
Port 19 TxQueue Drop Stats: 3055
Port 20 TxQueue Drop Stats: 2562
Port 21 TxQueue Drop Stats: 682
Port 22 TxQueue Drop Stats: 12466
Port 23 TxQueue Drop Stats: 19
Port 24 TxQueue Drop Stats: 0
Port 25 TxQueue Drop Stats: 0

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: 509
    Queue 9: 0
    Queue 10: 0
    Queue 11: 0
    Queue 12: 0
    Queue 13: 0
    Queue 14: 0
    Queue 15: 0

..

(output truncated)

Thanks.

PF

Reuben Farrelly · ‎11-28-2013

That's not a particularly large number of output discards especially for that platform. Do you have qos enabled on those ports by chance?

pokwan · ‎11-28-2013

Reuben,

Thanks for you reply.

Yes. This what we configured on the interface

auto qos voip trust

Thanks.

PF