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New Member

3560 Troubleshooting

I just installed a couple of 3560's in one of our buildings and a couple of days later users in that building were complaining that the network was slow. In particular our mac users were complaining that accessing network shares took a long time. On one 3560(switch A)Gig 0/1 is connected via fiber to our core 3550 in our server room. Gig0/2 is connected to Gig 0/2 on the second 3560. I noticed while observing the switches that on switch A gig 0/2 would flash amber and green every so often which seemed to coincide with instances of slowness. Could it be a bad GBIC? I am a newbie to troubleshooting these type of issues so any help would be appreciated.

Thanks.

Jeff

4 REPLIES
Purple

Re: 3560 Troubleshooting

Jeff,

The LEDs mean different things depending on which display mode is selected. If it's set to show port status, the alternating green-amber means there are errors on the links such as:

"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."

The following link has more info on what the LEDs mean:

http://www.cisco.com/en/US/products/hw/switches/ps5528/products_installation_guide_chapter09186a008043a542.html#wp1021241

I would check the output of 'sh interface ' on both switches to see what sort of errors you getting at. It may be as simple as a faulty cable.

Hope that helps - pls rate the post if it does.

Paresh

New Member

Re: 3560 Troubleshooting

Thanks Paresh. I also noticed that the uplinks on the 3560's were set to switchport mode dynamic desirable. I changed all of those ports to switchport mode trunk and switchport trunk encapsulation dot1q. I will take a look at the errors.

Thanks.

Jeff

Purple

Re: 3560 Troubleshooting

Generally the way you have is the cisco reccomended way of trunking (desirable). Look at the interfaces and look for errors and also look in the loggs for any problems like bouncing links . From the switch ping the addresses the users are complaining about and see if you are dropping anything and the ping response times . Unless you see errors on the connecting trunk links changing them won't do anything . Also you have to look on the 3550 side for errors also and look at the logs for problems .

New Member

Re: 3560 Troubleshooting

Jeff,

Can you post the config on the gig ports on each switch & also did you double check the server NIC setting?

mohAmed

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