four switches connected as the following topology.
link1
|sy2|-----------------|sy1|
|¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡|
|link2¡¡¡¡¡¡¡¡¡¡¡¡|link3
|¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡|
|sb2|-----------------|sb1|
link4
sy1 is the root and all links have same cost. Backbone fast is enabled on all these four switches. link2 on the sb2 end is blocked.
The question is if we disable the link4 on the sb1 end, what will sb2 and sy2 do? will sb2 send out bpdu to link2 claim that it is the root, or it will wait for the max age timer expired before it send bpdu out to the link2?
