Transmit Discards

[hellspire69_2]

Hi all

I have high transmit errors during the busy morning period on a uplink to the VPLS network. I have checked the switch and it is showing the output below.

The utilization on the uplink is only 50% or so. I am a little lost, does anyone have any advice which may help me resolve this issue?

Is it possible to turn off the qos on this interface for 5 minutes live without bring the network or interface down?  just to test?

show platform port-asic stats drop gigabitEthernet 0/24

  Interface Gi0/24 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 440341732

      Weight 1 Frames 92467

      Weight 2 Frames 23208381

[Leo Laohoo · Accepted solution]

Can you please post the output to the command "sh interface G0/24" and "sh controller e G0/24"?

[hellspire69_2]

GigabitEthernet0/24 is up, line protocol is up (connected)
  Hardware is Gigabit Ethernet, address is 0017.e077.72c1 (bia 0017.e077.72c1)
  Description: VPLS
  Internet address is 
  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 16/255, rxload 23/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:00, output hang never
  Last clearing of "show interface" counters 2d02h
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 12290746
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 90629000 bits/sec, 11817 packets/sec
  5 minute output rate 63378000 bits/sec, 9613 packets/sec
     3977210246 packets input, 4586628672294 bytes, 0 no buffer
     Received 496087 broadcasts (39376 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 485097 multicast, 0 pause input
     0 input packets with dribble condition detected
     4457772918 packets output, 5485968893248 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

e#show controllers ethernet-controller gigabitEthernet 0/24

     Transmit GigabitEthernet0/24             Receive
   2156466891 Bytes                       3627595659 Bytes
    894129573 Unicast frames              3988975919 Unicast frames
      1133589 Multicast frames              18129067 Multicast frames
           14 Broadcast frames                373001 Broadcast frames
            0 Too old frames              1287123706 Unicast bytes
            0 Deferred frames             2316601407 Multicast bytes
            0 MTU exceeded frames           23872064 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           987094086 Minimum size frames
            0 8 collision frames          3967388275 65 to 127 byte frames
            0 9 collision frames           269281402 128 to 255 byte frames
            0 10 collision frames         2350464522 256 to 511 byte frames
            0 11 collision frames         2899892216 512 to 1023 byte frames
            0 12 collision frames         2123292078 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
   3018484705 64 byte frames                       0 Valid frames, too small
   2748800354 127 byte frames
   1381982522 255 byte frames                      0 Too old frames
   1821155753 511 byte frames                      0 Valid oversize frames
   1333420860 1023 byte frames                     0 System FCS error frames
   3476320870 1518 byte frames                     0 RxPortFifoFull drop frame
            0 Too large frames
            0 Good (1 coll) frames
            0 Good (>1 coll) frames

[Leo Laohoo · Accepted solution]

I don't see any line errors, however, this interface is showing a significant amount of "Total output drops".  

This means that whatever is connected to this port is dropping packets like crazy.  

If this is your ISP, then I'm suspecting your ISP has some kind of traffic policing policy instead of a traffic SHAPING policy.  You may need to create traffic shaping so you don't drop packets.

[hellspire69_2]

It is going out to the VPLS network. However I thought that it might be an overly aggressive qos policy at our end?

[Leo Laohoo]

I'm not a QoS "kinda guy".  Joseph is one of THE QoS guys here in the forum.  

If this was an "aggressive QoS" then you'd see less output drops.  I could be wrong, but QoS won't work here.  You'll need to configure traffic shaping policy.  In Traffic shaping policy you could, for example, say that what goes down the link is 98% of a specified bandwidth.