6-16 Port Security ConfigurationWhen configuring port security, go to these sections for information you are interested in:z Introduction to Port Securityz Port Security Configuration Task Listz Displaying and Maintaining Port Securityz Port Security Configuration Examplesz Troubleshooting Port SecurityIntroduction to Port SecurityPort Security OverviewPort security is a MAC address-based security mechanism for network access controlling. It is anextension to the existing 802.1X authentication and MAC authentication. It controls the access ofunauthorized devices to the network by checking the source MAC address of an inbound frame andthe access to unauthorized devices by checking the destination MAC address of an outbound frame.With port security, you can define various port security modes to make a device learn only legal sourceMAC addresses, so that you can implement different network security management as needed. Whena port security-enabled device detects an illegal frame, it triggers the corresponding port securityfeature and takes a pre-defined action automatically. This reduces your maintenance workload andgreatly enhances system security.The following types of frames are classified as illegal:z Received frames with unknown source MAC addresses when MAC address learning is disabled.z Received frames with unknown source MAC addresses when the number of MAC addresseslearned by the port has already reached the upper limit.z Frames from unauthenticated users.The security modes of the port security feature provide extended and combined use of 802.1Xauthentication and MAC authentication and therefore apply to scenarios that require both 802.1Xauthentication and MAC authentication. For scenarios that require only 802.1X authentication or MACauthentication for access control, however, you are recommended to configure the 802.1Xauthentication or MAC authentication for simplicity. For information about 802.1X and MACauthentication, refer to 802.1X Configuration and MAC Authentication Configuration in the SecurityVolume.
