Collision errors with hub attached to 3750.

whiteford · ‎08-21-2009

Hi,

I'm getting collisions on a port on my 3750 where a 3com 10/100mb hib is attached. Due to hubs working in half duplex I decided to set the interface to "duplex half" and "speed auto" and the port goes down (no green or amber lights). If I set the interface to "duplex half" "speed 100" I get the same response, as soon as I do a "no duplex" and "no speed" the interface comes back up with and works but with collisons.

i thought setting to half duplex will remove the collisions not the function of the port :/ ?

Jon Marshall · ‎08-21-2009

"i thought setting to half duplex will remove the collisions not the function of the port :/ ?"

No it wont. If the link is running at half duplex then you will always see collisions. That is the whole idea of using a switch and running full duplex on the links ie. no collisions.

Is there a reason you are connecting hubs to your switches ?

Jon

whiteford · ‎08-21-2009

The single port goes into a test domain running tonens of packet ininstecting tools and sniffers. I span various ports from my stack to this port and the servers on the test domain get the info to analyse.

So a hub on a switch will always see collisions, no probs.