Cisco Certified Network Associate (CCNA) Practice Exam

Which command configures the maximum allowed MAC addresses for port security?

1. (config)#switchport port-security maximum NUMBER

2. (config)#switchport max-mac NUMBER

3. (config)#switchport port-security limit NUMBER

4. (config)#interface MAX MAC NUMBER

The correct answer is: (config)#switchport port-security maximum NUMBER

The command "switchport port-security maximum NUMBER" is used in Cisco networking to configure the maximum number of MAC addresses that can be learned on a specific switch port, which is a fundamental aspect of setting up port security. This command is crucial for preventing MAC flooding attacks, where a malicious user overwhelms a switch with fake MAC addresses, potentially disrupting network operations. Setting a limit on the number of MAC addresses helps enhance security by ensuring that only a defined number of devices are allowed to access the network through that port. When the specified number of MAC addresses is reached, the port can take pre-defined actions such as shutting down, restricting, or protecting the port to mitigate potential threats. Other choices do not correspond to valid Cisco commands for configuring port security's maximum MAC addressing capabilities. Most notably, "switchport max-mac NUMBER" and "switchport port-security limit NUMBER" are not standard command syntax, while "interface MAX MAC NUMBER" does not relate to configuring MAC address limits within the context of port security. This highlights the importance of using the correct syntax and understanding the intended functionality when working with network configurations.