Hey Network Experts,

at work our company does network service for multiple customers. Consistently again and again we have Spanning Tree Problems at various customers because of different reasons (Cisco and Enterasys Networks).

My questions is, How do you troubleshoot Spanning Tree failures or Loops in the network? Is there a best practice method? Is there a tool out there of monitoring the BPDU Counters of the Ports or something like that? How are your experiences?

Best Regards, Sunny

Depends on the STP issue your having. If your using a mix of different vendors gear you may need to make sure they are all using the same STP revision (802.1d for example). You also shouldn't be getting any loops (that would defeat the purpose of STP) unless someone configured portfast on a redundant switch link or something like that. As for tools to use, I know they exist, I'm thinking fluke probably makes something. Probably one of their DSP or Optiview models, but they can be pretty pricey. When ever I've had to trouble shoot an STP issue (with cisco gear) I just do it the old fashioned way; verify configs, walk the path that the data flows, and utilize cdp to make sure you Switch <-> Switch links are configured properly. However if you were to read a book it would probably say that 99% of the time STP issues are misconfiguration or someone mistakenly connected a HUB to create a redundant link between two switches.

HTH

-Ian