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New Member

CRC and Input errors? How to troubleshoot?

I have a Gig Fiber interface this incrementing like mad with crc and input errors. What is best method to troubleshoot?

CA-ANHM-HBR-R12-01#sh interfaces GigabitEthernet5/1

GigabitEthernet5/1 is up, line protocol is up

Hardware is GigMac 3 Port GigabitEthernet, address is 0005.00d5.5e81 (bia 0005.00d5.5e81)

Description: *** Gi - Core Services

Internet address is

MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec, rely 225/255, load 1/255

Encapsulation ARPA, loopback not set

Keepalive not set

Full Duplex, 1000Mbps, link type is force-up, media type is SX

output flow-control is unsupported, input flow-control is unsupported

ARP type: ARPA, ARP Timeout 08:00:00

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

Last clearing of "show interface" counters 00:16:13

Queueing strategy: fifo

Output queue 0/40, 0 drops; input queue 0/75, 0 drops

30 second input rate 239000 bits/sec, 55 packets/sec

30 second output rate 110000 bits/sec, 60 packets/sec

59400 packets input, 16361956 bytes, 0 no buffer

Received 28 broadcasts, 278 runts, 0 giants, 0 throttles

9679 input errors, 5459 CRC, 0 frame, 0 overrun, 0 ignored

0 watchdog, 502 multicast, 0 pause input

63231 packets output, 10346406 bytes, 0 underruns

Transmitted 429 broadcasts

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



Re: CRC and Input errors? How to troubleshoot?


U need to check or replace the fiber cable or patch cord.



New Member

Re: CRC and Input errors? How to troubleshoot?

You can also check if there is a duplex mismatch. This also causes CRC errors to increase rapidly