Configuring and Monitoring Port Security

MAC Lockout

MAC Lockout

MAC Lockout involves configuring a MAC address on all ports and VLANs for a switch so that any traffic to or from the “locked-out” MAC address will be dropped. This means that all data packets addressed to or from the given address are stopped by the switch. MAC Lockout is implemented on a per switch assignment.

You can think of MAC Lockout as a simple blacklist. The MAC address is locked out on the switch and on all VLANs. No data goes out or in from the blacklisted MAC address to a switch using MAC Lockout.

To fully lock out a MAC address from the network it would be necessary to use the MAC Lockout command on all switches.

To use MAC Lockout you must first know the MAC Address you wish to block.

Syntax: [no] lockout-mac < mac-address>

Lockout the specified MAC address.

How It Works. Let’s say a customer knows there are unauthorized wireless clients who should not have access to the network. The network administrator “locks out” the MAC addresses for the wireless clients by using the MAC Lockout command (lockout-mac<mac-address>). When the wireless clients then attempt to use the network, the switch recognizes the intruding MAC addresses and prevents them from sending or receiving data on that network.

If a particular MAC address can be identified as unwanted on the switch then that MAC Address can be disallowed on all ports on that switch with a single command. You don’t have to configure every single port—just perform the command on the switch and it is effective for all ports.

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