Why would a network administrator configure port security on a switch?

A.
to prevent unauthorized Telnet access to a switch port

B.
to prevent unauthorized hosts from accessing the LAN

C.
to limit the number of Layer 2 broadcasts on a particular switch port

D.
block unauthorized access to the switch management interfaces

Explanation:
You can use the port security feature to restrict input to an interface by limiting and identifying
MAC addresses of the stations allowed to access the port. When you assign secure MAC
addresses to a secure port, the port does not forward packets with source addresses outside
the group of defined addresses. If you limit the number of secure MAC addresses to one and
assign a single secure MAC address, the workstation attached to that port is assured the full
bandwidth of the port.
If a port is configured as a secure port and the maximum number of secure MAC addresses is
reached, when the MAC address of a station attempting to access the port is different from any
of the identified secure MAC addresses, a security violation occurs. Also, if a station with a
secure MAC address configured or learned on one secure port attempts to access another
secure port, a violation is flagged.