How to protect my Router OR Switch ports from attack /hacker ?

Use Port Security in the Switch

use following commands

CISCO(config)# int (your desired port)

CISCO(config-if)# switchport mode access

CISCO(config-if)# switchport port-security

CISCO(config-if)# switchport port-security maximum (number of system allowed to pass through that port)

CISCO(config-if)# switchport port-security mac-address (write down your desired mac address you want to allow or use command "sticky" to get mac address automatically when that mac address will hit the port)

CISCO(config-if)# switchport port-security violation shutdown/restrict/protect (use any one of these)

If you mean hysically by putting them into lockers and any LAN ports avaialabe (not used) on walls should be covered.

...I MEAN LOGICAL CONFGIURE ON ROUTER OR SWITCH