We are using Extreme and Enterasys product in my foundation.
Even though I configured spanguard on Enterasys B5 and B3, Spanguard didn't work.
I configured span guard on my switch as follows:
set spantree adminedge ge.1.1-23 true
set spantree spanguardtrapenable enable
set spantree spanguard enable
I'm waiting for your help.