Overview

Port security combines and extends 802.1X and MAC authentication to provide MAC-based network access control. This feature applies to networks, such as a WLAN, that require different authentication methods for different users on a port.

Port security provides the following functions:

• Prevents unauthorized access to a network by checking the source MAC address of inbound traffic.

• Prevents access to unauthorized devices or hosts by checking the destination MAC address of outbound traffic.

• Controls MAC address learning and authentication on a port to make sure the port learns only source trusted MAC addresses.

A frame is illegal if its source MAC address cannot be learned in a port security mode or it is from a client that has failed 802.1X or MAC authentication. The port security feature automatically takes a predefined action on illegal frames. This automatic mechanism enhances network security and reduces human intervention.

	NOTE: As a best practice, use the 802.1X authentication or MAC authentication feature rather than port security for scenarios that require only 802.1X authentication or MAC authentication. For more information about 802.1X and MAC authentication, see "Configuring 802.1X" and "Configuring MAC authentication."