ALternating Green-Amber Cisco Switch 3750

Hi there,

I have got Cisco 3750 switch. The port link changes from green to Amber after almost every 30 minutes. Below is the difnition I pasted from the cisco site.

Alternating green-amber
 Link fault. Error frames can affect connectivity, and errors such as excessive collisions, CRC errors, and alignment and jabber errors are monitored for a link-fault indication.

I am pretty sure one of the computers connected to switch causing this issue. can anyone help me how can i found which computer or computers causing network down.

Or do you think this something else causing this issue?
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Scotty_ciscoConnect With a Mentor Commented:
check speed and duplex on device hard set both ends the switch and the device problem should go away also look at a show int and look for errors if there are some what are they?

Sounds like duplex mismatch. Switchport set to auto speed/duplex and host set to 100/full - or the other way around?
Else, do you have dual-homed host using NIC teaming?
nepkAuthor Commented:
devices are working on 100Mbps and i haven't check the switch yet. To tell you one thing we haven't changed anything in our network.

Now i am going to server room and will hook the computer to console and will chekc the status of interfaces.

Do you think that virus or any malicious or spyware issue could cause problem?
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nepkAuthor Commented:
One more think what i have noticed that all ports goes to amber state not one. Each and every port after few seconds change to green then after half an hour goes to amber state.
No not usually this indicates a problem with traffic in the ports usually collisions or runts or giants.  This is either a configuration issue or a bad cable.

lrmooreConnect With a Mentor Commented:
All ports being flooded with broadcast storm?
What mode do you have the button in? There's a button on the face of the unit that changes the behavior of the lights..
nepkAuthor Commented:
1. what would be the status of the port when ports are getting broadcast storm.

Since I moved the cables to other switches Its look like the problem has been solved. Its mean the switch is faulty. I am now going to order for new switch.

any more thoughts

It may not be a faulty switch power cycle the switch and watch the post results first.... very likely that it could have been a bad connection if you do a show int fa 0/x where x is the port number does it show errors?
nepkAuthor Commented:
Ok i will check and let you know. actually we haven't made any changes and didn't install or plug new cable to switch.

anyways i will run show int command and then will let you know the result.
nepkAuthor Commented:
You have slected the wrong answer.

Even the cisco doesn't have the answer for this. We have done lots of thing but couldn't fix the problem.

Finally we have upgraded the IOS which has fixed the problem.

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