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New Member

Poor peformace on new LAN

I recently upgraded my LAN to a catalyst 6509 and 3525XL switches. Since then, my LAN peformance has gone downhill. The problems I am experiencing are as follows; Users getting disconnected from the LAN at random times. It only seems to happen when large amounts of data are being transfered across the network. (ie file transfers or network installations) Any suggestions??

4 REPLIES
New Member

Re: Poor peformace on new LAN

Hi Mike,

This could be an issue of speed/duplex mismatch between the switch ports and the NIC on the end stations. Auto speed/duplex on one side and 100/Full-duplex on the other side is a misconfiguration, and will result in a duplex mismatch.

Take a look at "sh port " and "sh mac " and look for errors. Check the port status when users complain that they are getting disconnected and confirm what is going on. Check "sh logging buffer -1023" for any messages logged in the circular buffer.

For Troubleshooting Cisco Catalyst Switches to Network Interface Card (NIC) Compatibility Issues, please refer to this document:

http://www.cisco.com/warp/customer/473/46.html

Nash

New Member

Re: Poor peformace on new LAN

You didn't mention what you upgraded from. We went from a flat 10mb concentrator based IDF to 100mb switch IDFs. I also introduced several subnets which greatly improved performance. Have you introduced subnets or is your architecture the same?

Another thing to consider is your physical plant. We have found some bad links that worked under our old 10mb concentrators but fail now that we are 100mb switched. Some links were over length, some were spliced (never know what you will find when you check your installers). I've even corrected some problems by repunching the patch panels with my 110 punch tool.

New Member

Re: Poor peformace on new LAN

try trunking between switches using three or four channels...

Best Regards / Sampath

SampathSR@yahoo.com, New York, NY.

New Member

Re: Poor peformace on new LAN

Also, in addition to what was already said, please check the following document.

http://www.cisco.com/warp/public/473/12.html

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