Does Cisco have command to test bad port on their devices?

I have used or refurbished 3560v2's and 3750v2's that may have or definitely have bad ports because some of my configs don't work completely and I don't think I'm doing anything wrong because I'm copy word for word out of the CCNP IP Switch version 7 or 6 lab manual when given a full config without having to figure any of it. The only thing that worked without any problems is MST. Is there a command to test bad ports on CIsco devices that can help me troubleshoot and know which ports are the good ones I can switch too.

I don't need to do this for my Routers because those are new 1921's and don't have any issue, but I couldn't buy new switches because I got turn down for a private for school considering my debt to income was to high and my federal student aid is exhaust until I hopefully make it to graduate school using grants. Can anyone help. If you need configs to help you determine which ports are bad let me know. I know I could just use the port lights, but isn't there a command or diagnostic I can run to determine this and please don't tell me I need SDM because I don't have it and can't get due nor having or being able to get Cisco support.

You bet they do. Depending on the IOS version, some commands may not be available. The easiest one on i believe 99% of all switches is "Show Post". That will tell you the diagnostic information of the switch when it booted up. It will let you know if the switchport controller has failed the tests right away.

There is also the possibility that you are running on a deferred version of IOS. Cisco sometimes will release a version then come to find out later that it causes problems. You can view the list on Cisco.com

If everything looks good there then the next would be to run a "Show interface (interface name)" That will show you what the port has been doing. The bottom part of that output is what you are looking for.

This is one of mine

5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
4319120 packets input, 415850103 bytes, 0 no buffer
Received 374001 broadcasts (186950 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 186950 multicast, 0 pause input
0 input packets with dribble condition detected
13389754 packets output, 1045108510 bytes, 0 underruns
0 output errors, 0 collisions, 1 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

Runts, input errors, CRC, frame, Overrun, underruns, output errors, collisions, babbles and buffer failures all point to issues on the line somewhere. Could be a bad patch cable, connector, a break in the wires.etc...

This next command will only work on your 3750s. I dont think it will work on the 3650.

#sh controller ethernet-controller fastEthernet 0/1

That will give you a detailed look at what type of traffic has been coming over the interface.



A peek at your configs wouldnt hurt. Some of the commands they may be using could be for a different version IOS and wont work on your current version. Other then typing a command and hitting tab, good luck on trying to find the list on Cisco's website of the commands that get removed/added on the versions.

documentation on Cisco's site http://www.cisco.com/c/en/us/support/docs/switches/catalyst-6500-series-switches/12027-53.html

bloodypulp said:

documentation on Cisco's site http://www.cisco.com/c/en/us/support/docs/switches/catalyst-6500-series-switches/12027-53.html

Click to expand...

Thanks, but the only command that seemed useful was show port and I only got the following from using it and it didn't help:


witch(config-if)#do show port
Secure Port MaxSecureAddr CurrentAddr SecurityViolation Security Action
(Count) (Count) (Count)
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Total Addresses in System (excluding one mac per port) : 0
Max Addresses limit in System (excluding one mac per port) : 6144
Switch(config-if)#exit
Switch(config)#exit
Switch#