We have a Core network which consists of two 6513s with 3524 connnected on the edge, these are connected via Gigabit connections configured as vlan trunks.
The core switches are running IOS 12.1(11b)E4.
I connected a 2948G to a 3524 10/100 port and configured the two ports to act as trunk, everything worked fine and the 2948G received all the correct VLAN information and switch was part of the network.
When I finished my testing I switched off the 2948G and within five minutes the VLANS on the core were going from Active to Standby and the switch processors were running at 100%.
The 2948G is running CATOS 5.5(11).
Does anyone have any ideas why this is happening? Could it be a bug or a configiguration that has gone.