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New Member

Very high collision rate on Cat6509 (ws-x6348)

We have immensely collision rates on 10/100tx ports connected to Lancast (Metrobility) media converters. To these are connected clients with ati2450 NICs. Though the collisions are above 10%, the network performance for the clients is not visibly reduced. The auto-negotiation results in a-10 and a-half.

What causes thisamount of collisions and how can they be reduced?

New Member

Re: Very high collision rate on Cat6509 (ws-x6348)

First thing I would try is to turn off the auto-negotiation and force duplex and speed to the desired setting on both the NIC and the 6509.

This may fix your problem.


Barry Hart


Re: Very high collision rate on Cat6509 (ws-x6348)

I agree , I haven't seen too many media converters that are auto negotiating , these ports should be hardcoded , if you connecting to another catos switch then it should be hardcoded to 10/full duplex to completly eliminate collisions .


Re: Very high collision rate on Cat6509 (ws-x6348)

After reading your reply further I see that it is connecting to clients , if the switch connected at 10 meg then the clients are not autonegotiating , if they were they would have negotiated at 100 meg , if the clients are able code to 10/full if not then code 10/half and make the switch port setting equal , do not use auto on the switch .