en
conf t

int g0/3
 switchport mode access
 switchport port-security
 switchport port-security mac-address 5000.3333.3333
 switchport port-security max 1
 switchport port-security violation shutdown
exit

do show run | sec 0/3
-----------------------------------
In kali pc
-------------
ping 8.8.8.8
macchanger -r eth0
ping 8.8.8.8
!! in switch -> do show interafaces status err 
                   -> int g0/3
                   -> shut 
                   -> no shut
macchanger -p eth0
ping 8.8.8.8