Collisions

[maff]

Hi,
We are an Art Institute in Dorset and have a LAN with two subnets seperated through a router. We have three main buildings each with thier own Summit switch installed connected via gigabit FDDI. These summits are divided into two VLANS corrosponding to the subnets.

We have been experiencing collisions on the network. One example is an uplink directly from a summit to a Asante switch and to a 10/100 hub. The cable has been checked and is fully working all the way to the summit, but we are getting constant collisions to the hub.

Any ideas, pleas help as we are desperate!!
[sig]<p>Matt ffolliott-Powell<br><a href=mailto:maff_ffolliottpowell@yahoo.com>maff_ffolliottpowell@yahoo.com</a><br><a href=

http://www.arts-inst-bournemouth.ac.uk>The

Arts Institute at Bournemouth</a><br>King of the wild frontier[/sig]

 

[Pritch5000]

Hey.
1. Try moving perimeter hubs (and all its device connections) to different ports see if the problem follows the hub or remains with the port, it could be a dodgy port.
2. Try swapping perimeter hubs (leaving all its device connections on the same switch portthru the new hub) around see if the problem follows the hub or remains with the port, it could be a dodgy hub.
3. Try switching off all computers connected to the affected hub. Check that the collision go away. Switch them back on one at a time, wait a good while between each one. See when the problem occurs, if you can identify it to be a specific machine. switch them all of again and repeat the process leaving the offending PC out of the equation. There could be more than one offending machines or it could be numbers. If it is machines it could be a driver, NIC or cable problem.
4. Swap patch leads around or replace them. Could still be cables.
5. Some hardware do not auto-sense 10/100 and half/full duplexing very well, particularly when you've different manufacturers. You can find that the switch is talking 100full and the hub is talking 100half or 10full or even 10half, or it could be hub and computer. Try forcing these settings.
Pritch. [sig][/sig]