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Switch Lights Blinking Fast

jpannorfi
Level 1
Level 1

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

11 Replies 11

Mohamad Qayoom
Level 3
Level 3

Just check to see if there is a duplex mismatch.

There are none.

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

Not blinking crazy and there are no performance issue.

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

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.

Any errors yet?

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 .

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

Leo Laohoo
Hall of Fame
Hall of Fame

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.

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

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