C3750 InError Count Increasing

lisechace · ‎02-16-2015

So, we have InError Count Increasing on some of our interfaces, but the traffic seems to be following fine. Below is one of our interface that have this issue.

#show interfaces GigabitEthernet 1/0/7 counters errors
Port        Align-Err     FCS-Err    Xmit-Err     Rcv-Err  UnderSize  OutDiscards
Gi1/0/7             0         142           0         142          0        33378
Port      Single-Col  Multi-Col   Late-Col  Excess-Col  Carri-Sen      Runts     Giants
Gi1/0/7            0          0          0           0          0          0          0

#show interfaces counters trunk
Gi1/0/7                 0               0            0

#show interfaces GigabitEthernet 1/0/7
GigabitEthernet1/0/7 is up, line protocol is up (connected)
  Hardware is Gigabit Ethernet, address is ----.----.---- (bia ----.----.----)
  Description: P2000 Array Controller/Top
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, media type is 10/100/1000BaseTX
  Media-type configured as  connector
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input never, output 00:00:05, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 33378
  Queueing strategy: fifo
  Output queue: 0/0 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 6000 bits/sec, 3 packets/sec
     81626118 packets input, 75658520521 bytes, 0 no buffer
     Received 320928 broadcasts (301617 multicasts)
     0 runts, 0 giants, 0 throttles
     143 input errors, 143 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 301617 multicast, 0 pause input
     0 input packets with dribble condition detected
     736927451 packets output, 71167510621 bytes, 0 underruns
     0 output errors, 0 collisions, 10 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

Why this errors can appear?

AllertGen · ‎02-17-2015

Hello, lisechace.

You're getting CRC errors. It's mean that Ethernet frames that you're recieving is damaged. The common source of this type of errors is physical problems (wire is more than 100 meters or damaged, problems with port and etc). If there is a lot of such problems you can try check the connection between devices.

Best Regards.

lisechace · ‎02-27-2015

Hello AllertGen.
Thank you. It seems you maybe are correct.

I performed some commands:

test cab tdr int gi 1/0/7
sh cab tdr int gi 1/0/7

and got this information

Interface Speed Local pair Pair length Remote pair Pair status
--------- ----- ---------- ------------------ ----------- --------------------
Gi1/0/7 100M Pair A 1 +/- 4 meters Pair A Normal
Pair B 1 +/- 4 meters Pair B Normal
Pair C 1 +/- 4 meters Pair C Short
Pair D 2 +/- 4 meters Pair D Short

Maybe there is issue with C and D pairs. I asked the engineers to check and replace the cables. They will do this on the next technical maintenance within the next 1 or 2 months. I will come back here when will have some additional information.

Leo Laohoo · ‎02-24-2015

81626118 packets input, 75658520521 bytes, 0 no buffer
     143 input errors, 143 CRC, 0 frame, 0 overrun, 0 ignored

Look at the value in blue. Now compare the value in green. Insignificant.

Total output drops: 33378

This, however, isn't something to put down lightly. Make sure the numbers are NOT incrementing.

If you want to learn stuff, post the output to the command "sh controller e G1/0/7".

lisechace · ‎02-27-2015

Hello Leo.

Thank you. Yes, it is not significant, but I want to know from where that errors came from.

Leo Laohoo · ‎02-27-2015

167 FCS errors

Came from here.

lisechace · ‎02-27-2015

sh controllers e GigabitEthernet 1/0/7

     Transmit GigabitEthernet1/0/7            Receive
   1829042511 Bytes                        107290089 Bytes
     83140528 Unicast frames                82111961 Unicast frames
    123169694 Multicast frames                282533 Multicast frames
    521994632 Broadcast frames                   109 Broadcast frames
            0 Too old frames                89068376 Unicast bytes
            0 Deferred frames               18082820 Multicast bytes
            0 MTU exceeded frames               6976 Broadcast bytes
            0 1 collision frames                   0 Alignment errors
            0 2 collision frames                 167 FCS errors
            0 3 collision frames                   0 Oversize frames
            0 4 collision frames                   0 Undersize frames
            0 5 collision frames                   8 Collision fragments
            0 6 collision frames
            0 7 collision frames             5214360 Minimum size frames
            0 8 collision frames            17977670 65 to 127 byte frames
            0 9 collision frames             5074726 128 to 255 byte frames
            0 10 collision frames            1794218 256 to 511 byte frames
            0 11 collision frames            2128505 512 to 1023 byte frames
            0 12 collision frames           50205291 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                  8 Invalid frames, too small
    343565052 64 byte frames                       0 Valid frames, too small
    304824453 127 byte frames
     61464937 255 byte frames                      0 Too old frames
     10677544 511 byte frames                      0 Valid oversize frames
      7085105 1023 byte frames                     0 System FCS error frames
       687763 1518 byte frames                     0 RxPortFifoFull drop frame
            0 Too large frames
            0 Good (1 coll) frames
            0 Good (>1 coll) frames