2950 server collisions

wrwiii122 · ‎10-25-2005

I have four servers plugged into ports on a 2950. Both the server and the switch are set to 100Mb half duplex. The NIC has flow control on. When I monitor each interface it has about 7% collisions on each one. I thought switches eliminate collisions? Is there flow control on the switch port? Any suggestions on what is causing this, are the collisions in the switch refering to the link between the server and switch or beyond?

glen.grant · ‎10-25-2005

You are getting collisions because you are running the port in half duplex which means one way communication at a time . You will always get get collisions on any half duplex line , if the server supports it ,it should be changed to full duplex . The counters are talking about the port connection between the server and the switch.

wrwiii122 · ‎10-25-2005

Thats what I thought but the other older IT guy is telling me that everything should run at half. Also any comments on the flow control? There is not much documentation on this. I understand it is used only for full duplex. Does it need to be set on both sides or one?

glen.grant · ‎10-25-2005

You shouldn't have to mess with flow controls with most installs ,(never have had to change it), leave it at defaults. Your other IT guy is incorrect ,everything should run at full duplex if it has the capability . I believe there were some old unix devices that couldn't run at full duplex so maybe thats what he remembers , any windows servers should be able to run full.

wrwiii122 · ‎10-26-2005

Thanks for your help. Should desktop be the same way or leave them at half until there are too many collisions?

b.orth · ‎10-26-2005

There is no reason to run anything at half duplex, unless it is old and only runs half duplex.

Why would you want collisions on your network?