Looking at the above figure we can determine that this SW1 is not the root bridge.
- The Address fields do not match, if this was the root bridge both mac address fields would match
- The STS (status) field is another give away, a root switch does not have any ports being blocked BLK
- Role is another sign, a root switch would not list another root switch in its connected interfaces.
|This is the root bridge as we can see the address fields match and all ports are in FWD|
Another way to tell would be to add the priority and the MAC address together creating the BID
Which is the root bridge?