TestOut LabSim A+ Certification Practice Exam

Which command is used to verify that TCP/IP is functioning correctly on a local computer?

1. tracert 127.0.0.1

2. ipconfig

3. ping 127.0.0.1

4. netstat

The correct answer is: ping 127.0.0.1

Using the command "ping 127.0.0.1" is an effective way to verify that the TCP/IP stack is functioning properly on a local computer. This command sends Internet Control Message Protocol (ICMP) echo request packets to the loopback address (127.0.0.1), which is a special IP address that routes the packets back to the same device. If the TCP/IP stack is working correctly, the computer will respond with echo reply packets, confirming that the network layer is operational. This method is specifically used to check the basic functionality of the networking software and stack on the computer without involving any external network devices or configurations. A successful ping to the loopback address indicates that core networking functions are active, which is a foundational step in diagnosing network-related issues. Other commands, while useful for different purposes, do not directly verify the TCP/IP functionality in the same clear and straightforward manner. For instance, running "tracert 127.0.0.1" is unnecessary for local verification because tracert is typically used to track the path packets take to a destination across a network, and 127.0.0.1 will always resolve to the local machine. The "ipconfig" command primarily displays