Cisco Certified Network Associate (CCNA) Practice Exam

What command allows you to apply a MAC access group to a specific interface?

1. SW1(config-if)#mac access-list extended LIST NAME

2. SW1(config-if)#mac access-group in/out

3. SW1(config)#interface INTERFACE

4. SW1(config)#ip nat inside

The correct answer is: SW1(config-if)#mac access-group in/out

To apply a MAC access group to a specific interface, the correct command is the one that specifically utilizes the "mac access-group" syntax. This command allows you to link an access control list (ACL) for MAC addresses with either incoming or outgoing traffic on a designated interface. Using "mac access-group in/out" enables you to define how the switch or device processes frames based on MAC addresses for that specific interface. When you specify "in," it applies the access list to incoming traffic, whereas "out" applies it to outgoing traffic. This capability is crucial for network security, allowing administrators to control which devices can communicate on the network based on their MAC addresses. The other options listed do not achieve the same purpose. For instance, using "mac access-list extended LIST NAME" actually creates a MAC access list but does not apply it to any interface. The command "interface INTERFACE" does simply switch to interface configuration mode but does not apply any access control. Lastly, "ip nat inside" pertains to NAT configurations and does not relate to MAC address filtering or access control lists.