Daisy Chained Switches - spanning tree problems lurking

Ran into a situation where a customer had 8 cisco 2950 switches patched randomly into each other. Cleaned the configuration up where 1 master switch will feed all the other switches. Ideally this will be replaced with a 3560 gig switch. Here is what happens to layer2 networks that keep growing as users add new switches. Normally routers would be used to break up large layer2 domains but sometimes companies forget to do this and a mess can result. http://www.cio.com.au/article/65115/all_systems_down/     For cisco switches BPDU Guard is very helpful. Any loop beyondthe edge port would also return BPDUs from your switch and thus disablethe port in the event of a loop.   In the event a device gets added that allows a loop but filters BPDUs then "switchport port-security maximum" and "switchport port-security violation shutdown" might help by shutting down the affected port.