they are some switches that I have just taken over, they are nortel 450T, I normally use cisco so Im new to them, spanning tree is enabled on them and surely if there was a loop it would of been blocked ?? if im using ethereal what should I be looking for ??

thanks a million

Cisco and Nortel deal with Spanning Tree in totally different ways (almost 90 degrees).

Cisco does Per VLAN Spanning Tree as default, Nortel puts all the VLANs in one spanning tree instance by default, as one example.

Cisco includes all VLANs in a trunk port unless EXCLUDED, Nortel EXCLUDES all VLANs ina "tagged" port unless included..

And don't even get started with "etherchannel" vs what Nortel calls "trunking" (link aggregation) and compatibility..

If things were running before and you don't/haven't added/removed/changed VLANs on ports, then this might not be the problem, but if you do, it can create a huge STP loop problem.

I've run into compatibility issues before, and usually, the easiest way to troubleshoot is to not have to go cross-vendor... Other option would be to use access ports (instead of trunk ports) on a single VLAN to link the 450T up to the core, that would eliminate some of the STP agita that can occur.

Good luck --

...Nick

these are some stats from a port in vlan 1

these are average per sec

InOctets 18,975.19

OutOctets 15,912.68

InUcastPkts 91.53

OutUcastPkts 37.57

InMulticastPkts 44.03

OutMulticastPkts 0.17

InBroadcastPkts 0.54

OutBroadcastPkts 0.08

does this say anything ????