You need to configure port security on switch R1. Which two statements are true about this
technology? (Select two)

A.
Port security can be configured for ports supporting VoIP.

B.
With port security configured, four MAC addresses are allowed by default.

C.
The network administrator must manually enter the MAC address for each device in
order for the switch to allow connectivity.

D.
With port security configured, only one MAC addresses is allowed by default.

E.
Port security cannot be configured for ports supporting VoIP.

Explanation:
You can use the port security feature to restrict input to an interface by limiting and
identifying MAC addresses of the workstations that are 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.
This feature is indeed supported on voice VLAN ports. If you enable port security on a port
configured with a voice VLAN and if there is a PC connected to the Cisco IP Phone, Cisco
tells us to set the maximum allowed secure addresses on the port to at least 3.
The table below shows the default number of allowed MAC addresses is one.
Default Port Security Configuration

Reference: Configuring Port Security
http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.1E/native/configuration/g
uide/port_sec.html#wpxref25516