CRC errors increasing, but pingtests are 100% ok!

[SlevinKelevra]

Gents,

My crc errors are steadily increasing on the Ethernet segment, but when i ping the BGP neighbor (so packets travel accross this "bad" segment) i do not see any packets going bad. Anyone got an explanation for this?

How is this possible, i would expect at least something going wrong with my ping test.

Unfortunately Google could not help me.

xxxx#ping xxx.22x.193.174 repeat 1000 size 1400

Type escape sequence to abort.
Sending 1000, 1400-byte ICMP Echos to xxx.22x.193.174, timeout is 2 seconds:
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!
Success rate is 100 percent (1000/1000), round-trip min/avg/max = 232/251/552 ms               <===

xxxx#sh int Fa0/0

FastEthernet0/0 is up, line protocol is up

  Hardware is Gt96k FE, address is 001f.9ee5.d32a (bia 001f.9ee5.d32a)

  Description: ISP

  Internet address is xxx.12x.110.226/27

  MTU 1500 bytes, BW 100000 Kbit/sec, 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, 100BaseTX/FX

  ARP type: ARPA, ARP Timeout 04:00:00

  Last input 00:00:18, output 00:00:00, output hang never

  Last clearing of "show interface" counters 00:05:28

  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

  Queueing strategy: fifo

  Output queue: 0/40 (size/max)

  5 minute input rate 214000 bits/sec, 76 packets/sec

  5 minute output rate 232000 bits/sec, 72 packets/sec

     25999 packets input, 9368996 bytes

     Received 7 broadcasts, 0 runts, 0 giants, 0 throttles

     66 input errors, 66 CRC, 0 frame, 0 overrun, 0 ignored               <===

     0 watchdog

     0 input packets with dribble condition detected

     25199 packets output, 10021048 bytes, 0 underruns

     0 output errors, 0 collisions, 0 interface resets

     6 unknown protocol drops

     0 babbles, 0 late collision, 0 deferred

     0 lost carrier, 0 no carrier

     0 output buffer failures, 0 output buffers swapped out

[Rizwan Khan]

Hello,
Are the crc growing still? There is a possibility thay they might be generated before and the cable is good now. Try clearing the interface counters and again ping and check the interface status.


Sent from Cisco Technical Support Android App

[SlevinKelevra]

I have send out a NEW wic card to the site, we are going to replace it, both sides are configured as 100/full hard coded (auto neg = off) Will keep you posted!

[Dinesh Kumar Mariappan]

Reasons for CRC error.

1. cable issue( some times cross cable will used instead of Straight cable vice versa).

2: Duplex and Speed mismatch.

After replacing this two still problem persist then might problem with port..

Once replaced cable and Configuration.. Before generating ping clear the counters and observe the errors..

[Leo Laohoo]

full hard coded (auto neg = off)

If you have two Cisco devices, I'd recommend you enable auto-negotiation.  When you hard-code the speed and duplex, you'll see more line errors.