Security was one of the first features for securing network ports. Access to the network via this address controlled. The MAC can access port to specific MAC addresses or a number of addresses to be limited.
In violation of a defined traffic rules can be filtered (violation protect or restrict) or the interface will be disabled (shutdown violation).
Port Security Setup
Port Security is configured on the interface.
interface FastEthernet0 / 1
switchport mode access
switchport port-security
Without further parameter is the number of allowable MAC addresses on a set and the Violation Action on shutdown.
Port Security is to limit the number of connected devices (MAC addresses) per switch port. This allows the installation of “wild” Edge switches to prevent ports quite effective.
True security is port security, but difficult to achieve with and the administrative work is very high.