Spanning-Tree Backbone Fast

Lessons Discussion
7

let me clarify this, correct me if im wrong. this is what i understand on this lesson

  • Link between Sw A and Sw B is down. so Switch B will not receive any BPDU's from root bridge, claiming he's the root bridge.
  • since the link between A and B is down, Switch B's BPDU will send through Switch C.
  • Now switch C receives this BPDU and identifies it as inferior BPDU.
  • Since it receives an inferior BPDU, Switch C will send a Root Link Query on its Root Port to check if the root bridge is still available (this is the purpose of RLQ? to check if root bridge is available? because Switch B is claiming he's the new root bridge, so Switch C just want to verify if root bridge is still alive)
  • now, if Switch C receives a response on his RLQ, it means the root bridge is alive right? then on Switch C's block port, it will skip the max age timer (20secs) and it will go straight listening mode then learning.
is this right? if this is right, then i have a question,

what if Switch C sends a RLQ and didnt receive a response? what will happened? Switch B will be the new root bridge? what is the process?

or i think it will not go through this long process, because not receiving a RLQ response means the RootBridge is dead right? it means directly connected port of Switch C to RootBridge will also detect a link failure, also Switch B will detect a link failure.