A Protected Port does not forward unicast, broadcast, or multicast packets to any other port that is also a protected port. Control Plane traffic is still forwarded, but Layer 2 Data Plane traffic that needs to pass between two protected ports must pass through a Layer 3 switch. Forwarding between a protected port and a nonprotected port proceeds as usual.
The Protected Port feature can be configured on a physical interface or on an EtherChannel group.
SW1(config)# interface GigabitEthernet0/1
SW1(config-if)# switchport protected
SW1(config-if)# exit
Protected ports only have local switch significance.