A.0.0.0.1 B.0.255.0.1 C.2001:DB8::1 D.2001:DB8:ABCD:FEEF::1
A.excessive collisions B.FCS errors C.runts D.late collisions
A.BPDUs that enter a blocking port are discarded. B.BPDUs that enter a blocking port are processed. C.Loopguard puts an interface into a loop-inconsistent state when BPDUs stop being received on a blocking port. D.BPDUs are only processed on forwarding ports.