Which command is used on a Catalyst 2950 series switch to enable basic port security on the interface?

A.
set port-security

B.
switchport port-security

C.
set port-security enable

D.
switchport port-security enable

Explanation:
The switchport port-security command is an interface configuration command used on a Catalyst 2950 series
switch to enable basic port security on the interface. The syntax of the command is as follows:
switch(config-if)#switchport port-security
Switchport security can be used to:
Limit the computers that are allowed to connect to the LAN (by specifying the MAC addresses allowed on
the port)
Limit the number of MAC address allowed to be accessing a port
Set the action the port will take when a violation of the security rule occurs
The set port-security, set port-security enable, and switchport port-security enable commands are incorrect
because these are not valid Cisco IOS commands.
Objective:
Infrastructure Security
Sub-Objective:
Configure, verify, and troubleshoot port security

Cisco > Catalyst 2950 and Catalyst 2955 Switch Command Reference, 12.1(22)EA11 and Later > Catalyst
2950 and 2955 Switch Cisco IOS Commands – s > switchport port-security