Switch Lights Blinking Fast

[jpannorfi]

Can anyone tell me if there's a problem with lights on a switch (Model Doesn't Matter, Different VLANs) or I should say every switch blinking fast?

Thanks In Advance

[Mohamad Qayoom]

Just check to see if there is a duplex mismatch.

[jpannorfi]

There are none.

[mikegrous]

if a switch is blinking like crazy and performace is slow or non exsistat id check for a loop. Is the performance degregated?

[jpannorfi]

Not blinking crazy and there are no performance issue.

[Mohamad Qayoom]

Do "sh int cou err" to see if there are any errors.

[jpannorfi]

This switch has been operational for about 5 years. There were some errors, but I cleared the counters and I don't see any errors for the last 20 minutes.

[Mohamad Qayoom]

Any errors yet?

[glen.grant]

Find out what model then do a search in CCO for the model you have and what the LEDS mean on the front . I never use them other than to make sure it has power anyway .

[vineesh.viswanath]

is every switch in same vlan ? if so it could be arp broadcast

[Leo Laohoo]

What is the color of the LED? Green or amber/red? Look at the status light (over on the left). Is it Green or Amber/Red?

Model does make alot of difference. The 2900/3500XL switch port LED goes red when line errors occur (such as duplex or speed mismatch). If amber/red is constantly on (as compared to occassional blinking), it means that the port(s) have failed (Loopback test failure) or spanning-tree port blocking.

For other models after this generation of switches, amber/red lights constantly on on the switch means either ports are error-disable, ports down due to Trunking mismatch, duplex/speed mismatch, etc, or spanning-tree port blocking.

[glen.grant]

It also depends in what mode it is in on front . There is usually a mode button on the left that you you push and it will cycle thru like utilization and status and maybe one other state. For like a 2950 take a look here.

http://www.cisco.com/en/US/docs/switches/lan/catalyst2950/hardware/installation/guide/hgovrev.html#wp1089458