220-1101 Question 167
Single answer2.8 Explain networking tools and their purposes.A technician is troubleshooting a workstation that cannot reach a file server by hostname, but it can successfully connect to the server by IP address. The user reports that the issue started after a network change earlier that day. The technician wants to quickly verify whether the problem is related to DNS name resolution from the affected PC. Which tool should the technician use FIRST?
- A
nslookup
- B
crimper
- C
tone generator and probe
- D
cable tester
Show answer and explanation
Correct answer: A
Explanation
This question focuses on selecting the correct networking tool for the symptom presented. If a device can communicate with a remote system by IP address but not by hostname, the most likely issue is DNS resolution. The best first tool to use is nslookup because it directly tests whether DNS can resolve the target name and whether the configured DNS server is responding correctly. In A+ Core 1, candidates are expected to match tools to practical troubleshooting situations. CompTIA's networking objectives emphasize understanding the purpose of tools such as cable testers, crimpers, tone generators, and software utilities like nslookup. Best practice in troubleshooting is to choose the tool that most directly validates the suspected fault domain before moving to unrelated physical-layer tools.
- A. Correct.
Correct. nslookup is the appropriate tool to test DNS name resolution directly from the workstation. In this scenario, the PC can reach the server by IP address but not by hostname, which strongly suggests a name resolution issue rather than a basic connectivity issue. Using nslookup allows the technician to query DNS and determine whether the hostname resolves to the correct IP address.
- B. Incorrect.
Incorrect. A crimper is used to attach connectors, such as RJ-45 ends, to network cabling. It is useful when creating or repairing Ethernet cables, but it does not test DNS resolution or help determine whether a hostname can be translated into an IP address.
- C. Incorrect.
Incorrect. A tone generator and probe are used to identify and trace cables in walls, patch panels, or bundles. A technician might use this tool when locating the physical path of a cable, but it does not verify DNS functionality or hostname resolution from a workstation.
- D. Incorrect.
Incorrect. A cable tester checks cable continuity, wire mapping, shorts, and related physical-layer issues. Although physical cabling problems can cause connectivity failures, the scenario specifically states that the workstation can connect by IP address, which indicates the network path is functioning. That makes DNS testing the more appropriate first step.