Cisco Certified Network Associate (CCNA) Practice Exam

What command is used to display information about a specific router interface?

1. show interface

2. show ip interface INTERFACE NUMBER

3. display router interface

4. show routing interface

The correct answer is: show ip interface INTERFACE NUMBER

The command used to display information about a specific router interface is indeed "show ip interface INTERFACE NUMBER." This command provides detailed information about the specified interface, including its IP address, status (up or down), and other attributes such as the encapsulation type and whether it is administratively down. The reason this command is particularly effective is that it allows network administrators to troubleshoot specific interfaces by providing targeted information. By specifying the interface number, the administrator can quickly access relevant data without sifting through information about all interfaces on the router. Other commands in the options may provide broader insights or are not valid commands in the context of Cisco IOS. For instance, "show interface" displays details for all interfaces or a specific one based on the additional context given, but it lacks the specificity of addressing a single interface's IP details directly. "Display router interface" is not a recognized command in Cisco's command-line interface. Lastly, "show routing interface" does not exist as a command, as it may confuse routing tables with physical interfaces. Each of these misconceptions highlights why focusing on "show ip interface INTERFACE NUMBER" is the most effective approach for retrieving precise interface information.