CRC errors on cisco switch

Srinivas N · ‎06-23-2012

Dear All,

One of my wi-fi site having 2nos cisco 2950 switchs. in that network some D-link unmanageble swithes also there

and access points also connected to cisco switchs and D-link switchs.

after one or two days i am not able to connect the wi-fi, then i need to restart the access point then only wi-fi is working fine.

I upgraded the latest ios also.

I connected some access points to the cisco switch ports, those ports are showing crc error messages like below.

145 input errors, 144 CRC, 1 frame, 0 overrun, 0 ignored

and log file also show some errors like below.

000186: Jun 23 03:44:01: %SYS-5-CONFIG_I: Configured from console by vty0 (115.1

19.187.45)

000187: Jun 23 05:44:36: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEth

ernet0/5, changed state to down

000188: Jun 23 05:44:38: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEth

ernet0/5, changed state to up

000189: Jun 23 06:38:19: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEth

ernet0/5, changed state to down

000190: Jun 23 06:38:21: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEth

ernet0/5, changed state to up

000191: Jun 23 06:38:25: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEth

ernet0/5, changed state to down

000192: Jun 23 06:38:27: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEth

ernet0/5, changed state to up

what could be the problem,

I updated the lates IOS and changed the RJ45 connector both side.

Plz help on this.

Thanks,

Srinivas. N.

Thanks & Regards, Srinivas. N.

Leo Laohoo · ‎06-23-2012

Kindly post the output to the following commands:

1. sh run int f 0/5;

2. sh contr e f 0/5

3. sh interface f 0/5

Srinivas N · ‎06-23-2012

Hi leolaohoo,

Thanks for reply and plz find the sataus.

GP_VIZAG_MAINSW_2950#sh run int fa0/5

Building configuration...

Current configuration : 122 bytes

!

interface FastEthernet0/5

description * Back Side-I (Proxim) *

switchport access vlan 10

switchport mode access

end

GP_VIZAG_MAINSW_2950#sh cont

GP_VIZAG_MAINSW_2950#sh controllers e

GP_VIZAG_MAINSW_2950#sh controllers ethernet-controller fa0/5

Transmit Receive

4111734682 Bytes 800406706 Bytes

5324004 Frames 3132634 Frames

723276 Multicast frames 167 FCS errors

411370 Broadcast frames 51740 Multicast frames

0 Pause frames 21924 Broadcast frames

0 Single defer frames 0 Control frames

0 Multiple defer frames 0 Pause frames

0 1 collision frames 0 Unknown opcode frames

0 2-15 collisions 1 Alignment errors

0 Late collisions 0 Length out of range

0 Excessive collisions 122 Symbol error frames

0 Total collisions 61932 False carrier errors

0 Control frames 0 Valid frames, too small

0 VLAN discard frames 0 Valid frames, too large

0 Too old frames 0 Invalid frames, too small

0 Tagged frames 0 Invalid frames, too large

0 Aborted Tx frames 0 Discarded frames

Transmit and Receive

1355392 Minimum size frames

2785635 65 to 127 byte frames

930782 128 to 255 byte frames

291326 256 to 511 byte frames

284047 512 to 1023 byte frames

2809456 1024 to 1518 byte frames

0 1519 to 1522 byte frames

GP_VIZAG_MAINSW_2950#sh int

GP_VIZAG_MAINSW_2950#sh interfaces fa0/5

FastEthernet0/5 is up, line protocol is up (connected)

Hardware is Fast Ethernet, address is 0012.00fe.d6c5 (bia 0012.00fe.d6c5)

Description: * Back Side-I (Proxim) *

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 100BaseTX

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

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

Last input never, output 00:00:01, output hang never

Last clearing of "show interface" counters 2d02h

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 0 bits/sec, 0 packets/sec

5 minute output rate 1000 bits/sec, 1 packets/sec

1902845 packets input, 534271423 bytes, 0 no buffer

Received 42355 broadcasts (28994 multicast)

0 runts, 0 giants, 0 throttles

145 input errors, 144 CRC, 1 frame, 0 overrun, 0 ignored

0 watchdog, 28994 multicast, 0 pause input

0 input packets with dribble condition detected

2943416 packets output, 2240492645 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

GP_VIZAG_MAINSW_2950#

Thanks & Regards, Srinivas. N.

Leo Laohoo · ‎06-23-2012

Ok, good.

Your line errors are mostly coming from FCS and Symbols.

Mostly, this is attributed due to faulty cabling.

changed the RJ45 connector both side.

What do you mean by this?

Are you using a factory pre-terminated patch cables or did you crimp them yourself?

Srinivas N · ‎06-23-2012

Thanks for quick reply,

what is meangin of FCS and symbols?

The cat cable is about to 70mts and i my self crimped the connectors.

Thanks & Regards, Srinivas. N.

Leo Laohoo · ‎06-23-2012

The cat cable is about to 70mts and i my self crimped the connectors.

Test the cables with a TDR meter.

Srinivas N · ‎06-25-2012

Hi Leolaohoo,

After reclimping the RJ45 connetors and clear the counter.

Now that port status like below

GP_VIZAG_MAINSW_2950# sh controllers e f0/5

Transmit Receive

880211912 Bytes 342010269 Bytes

1214521 Frames 913135 Frames

139288 Multicast frames 0 FCS errors

96737 Broadcast frames 5471 Multicast frames

0 Pause frames 2198 Broadcast frames

0 Single defer frames 0 Control frames

0 Multiple defer frames 0 Pause frames

0 1 collision frames 0 Unknown opcode frames

0 2-15 collisions 0 Alignment errors

0 Late collisions 0 Length out of range

0 Excessive collisions 0 Symbol error frames

0 Total collisions 134 False carrier errors

0 Control frames 0 Valid frames, too small

0 VLAN discard frames 0 Valid frames, too large

0 Too old frames 0 Invalid frames, too small

0 Tagged frames 0 Invalid frames, too large

0 Aborted Tx frames 0 Discarded frames

Transmit and Receive

406912 Minimum size frames

681005 65 to 127 byte frames

205184 128 to 255 byte frames

63193 256 to 511 byte frames

82091 512 to 1023 byte frames

689271 1024 to 1518 byte frames

0 1519 to 1522 byte frames

GP_VIZAG_MAINSW_2950#

now advice me,...

Thanks & Regards, Srinivas. N.

Leo Laohoo · ‎06-25-2012

Looks good to me. FCS and Symbol errors are "0", no collisions.

Srinivas N · ‎06-25-2012

what about the

134 False carrier errors

no problem?

Thanks & Regards, Srinivas. N.

jimmysands73_2 · ‎06-25-2012

No problem? Are you looking for one? Because with all the counters I am sure you can find one if you look hard enough.

My boss once told me there was no such thing as a perfect design, I disagreed...I said "What about Holly Madiison, now thats a perfect design ". I am just saying lol!

Moving on .... Check out:

https://supportforums.cisco.com/thread/157286

and from Ciscos site:

False carrier errors

The number of occurrences in which the interface detects a false carrier when frames are not sent or received.

IMO, while I have not seen this type of error before, you are seeing speed/duplex mismatches disguised as false carrier or a pure layer one issue.

Leo Laohoo · ‎06-26-2012

134 False carrier errors

I'm with Jimmy. I have never seen this line error before. I didn't miss this.

Keep an eye on the counter. If the counter goes up, by 50%, daily then you have a problem.

Srinivas N · ‎06-28-2012

As of now the fales carrier errors are 539...

Is it make any problem?.. if i want fix the problem what i need to do?

Transmit Receive

945130476 Bytes 704286385 Bytes

4627987 Frames 2896862 Frames

493692 Multicast frames 0 FCS errors

310672 Broadcast frames 24905 Multicast frames

0 Pause frames 5318 Broadcast frames

0 Single defer frames 0 Control frames

0 Multiple defer frames 0 Pause frames

0 1 collision frames 0 Unknown opcode frames

0 2-15 collisions 0 Alignment errors

0 Late collisions 0 Length out of range

0 Excessive collisions 0 Symbol error frames

0 Total collisions 539 False carrier errors

0 Control frames 0 Valid frames, too small

0 VLAN discard frames 0 Valid frames, too large

0 Too old frames 0 Invalid frames, too small

0 Tagged frames 0 Invalid frames, too large

0 Aborted Tx frames 0 Discarded frames

Transmit and Receive

1496870 Minimum size frames

2061206 65 to 127 byte frames

813245 128 to 255 byte frames

225429 256 to 511 byte frames

261930 512 to 1023 byte frames

2711638 1024 to 1518 byte frames

0 1519 to 1522 byte frames

P_VIZAG_MAINSW_2950#

Thanks & Regards, Srinivas. N.

jimmysands73_2 · ‎06-28-2012

1) Is there a problem from a end user perspective?

2) Can you move it to a diff port to see if problem stays on port or cable

3) If problem follows cable, on the remote device can you move port to see if problem stays with port or cable.

4) I believe problem will be with cable, if so, new cabling (or ends).

Leo Laohoo · ‎06-28-2012

Dude,

Let's settle this once and for all.

How important is this client connected to this port? If it's that important, GET A TDR TEST DONE!

jimmysands73_2 · ‎06-28-2012

For the OP:

How to use Time-Domain Reflectometer (TDR)

https://supportforums.cisco.com/docs/DOC-18983

Post results.