預設 port-security maximum 為1
switch #conf t
switch (config)#interface fastEthernet 0/24 (例如在24埠設定)
switch (config-if)#switchport mode access (Port改成Access Mode)
switch (config-if)#switchport port-security (啟用Port Security)
switch (config-if)#switchport port-security maximum 3 (設定最大的MAC數量為3)
switchport port-security mac-address 001b.ad94.6d34(第一組)
switchport port-security mac-address 002b.bd94.7d34(第二組)
switchport port-security mac-address 003b.cd94.8d34(第三組)
switchport port-security violation {protect | restrict | shutdown(預設)}