Spanning Tree Blocking Port

[burhanburhan]

Hi all, please see the attached. 

SW0 has lower bridge ID than SW1, but SW0 fa0/1 port is in blocking mode. Why? Isn't lower is better ?

SW3 is root bridge.

SW O 33342
Mac : 0002.4AC7.115A

SW1 33342
Mac: 00D0.97D7.58A0

[Milos Megis · Accepted solution]

Hi,
it should be due to fact that root path cost of SW1 is lower than root path cost of SW0.

Because in this step is decided which BPDU is better, sender bridge IDs are not compared.

[burhanburhan]

thank you Milos.