CRC errors on Ethernet port

Unanswered Question

this is my Cisco 2600 Ethernet port:

Ethernet0/0 is up, line protocol is up

Hardware is AmdP2, address is 0005.3286.7ca0 (bia 0005.3286.7ca0)

Description: LAN on VLAN42

Internet address is 192.168.42.3/24

MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

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 never

Queueing strategy: fifo

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

5 minute input rate 7000 bits/sec, 4 packets/sec

5 minute output rate 6000 bits/sec, 5 packets/sec

54427244 packets input, 1856974710 bytes, 0 no buffer

Received 8074229 broadcasts, 0 runts, 0 giants, 0 throttles

46267 input errors, 46267 CRC, 42567 frame, 0 overrun, 0 ignored

0 input packets with dribble condition detected

46283675 packets output, 877298486 bytes, 0 underruns(0/0/0)

40 output errors, 0 collisions, 3 interface resets

0 babbles, 0 late collision, 0 deferred

40 lost carrier, 0 no carrier

0 output buffer failures, 0 output buffers swapped out

interface Ethernet0/0

description LAN on VLAN42

ip address 192.168.42.3 255.255.255.0

full-duplex

end

********************************************

this is the other end - Cisco 3560G:

interface GigabitEthernet0/5

switchport access vlan 42

switchport mode access

duplex full

spanning-tree portfast

end

GigabitEthernet0/5 is up, line protocol is up (connected)

Hardware is Gigabit Ethernet, address is 0017.e040.4185 (bia 0017.e040.4185)

MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Full-duplex, 10Mb/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 00:00:52, output 00:00:01, output hang never

Last clearing of "show interface" counters never

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 7000 bits/sec, 6 packets/sec

5 minute output rate 11000 bits/sec, 11 packets/sec

44681598 packets input, 969282128 bytes, 0 no buffer

Received 302392 broadcasts (0 multicast)

0 runts, 0 giants, 0 throttles

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

0 watchdog, 296938 multicast, 0 pause input

0 input packets with dribble condition detected

130929196 packets output, 432025420 bytes, 0 underruns

0 output errors, 0 collisions, 3 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 do I get CRC errors?

do I have to set the 3560 to 10mb?

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Loading.
thotsaphon Mon, 05/05/2008 - 11:27

Hi Ofir,

Did you already check/change the cable first?

For testing:

Can you hard-code the switch and the router to be 10Mb/Full Duplex?

Hopes this helps

Thot

didn't replace the cable - will do after hours today

about hard-coding 10Mb/Full, both have Full Duplex coded. the reason I didn't code 10Mb on the 3560 is that the 2600 does not have the option to encode speed. I assume it has 10Mb coded by default.

I'll try coding the 3560 to 10Mb (though the errors only show on the 2600)

thanks (and I'll be back with an update)

burleyman Mon, 05/05/2008 - 11:44

CRC errors ussally indicated a physcial issue. I would clear the counters and see if they are still going up as they could be old errors because the counters have never been cleared. If they continue to increase I would replace the cable to start with and then clear the counters again and see if they continue.

Hope this helps,

Burleyman

burleyman Tue, 05/06/2008 - 04:06

I would just keep monitoring the ports. If the errors don't return they may have been some old errors from when the switch was deployed. You could still swap out the cable but if the errors are not coming back you could hold off. Again, CRC errors usually point to a physical problem, i.e. bad cable, bad port, but could still increment if there were allot of collisions due to a duplex mismatch but there were 0 Collisions so I don't think that was it.

Hope that helps,

Burleyman

burleyman Tue, 05/06/2008 - 04:08

Also, forgot one thing. If you had a speed/duplex issue the counters would continue to climb after you cleared the interface counters.

Burleyman

lamav Mon, 05/05/2008 - 11:53

Hi:

Swap the ethernet cables out with known good ones.

The try using new ports.

CRC errors usually indicate bad hardware.

HTH

Victor

glen.grant Tue, 05/06/2008 - 03:31

I know on some of the old 2600's they would not do full duplex even though the duplex command was there so if the 2600 is half duplex and the 3560 is set as full duplex you have a speed duplex mismatch and thats why you are seeing crc's and errors .

Actions

This Discussion