Which command line tool queries and troubleshoots DNS problems?

• A. Dig
• B. DNS
• C. DDoS
• D. Direct

Answer: (A)

DNS troubleshooting centers on querying name records to verify how a domain should resolve and where the process is breaking. The command-line tool designed for this is dig, a flexible DNS lookup utility. It lets you query specific DNS servers, request particular record types (A, AAAA, MX, NS, TXT, and more), and inspect the full response with details such as authority, caching, and flags. This level of control helps you pinpoint issues like incorrect records, missing delegations, or stale caches.

For example, dig example.com A retrieves the A record for the domain, showing the IP address. You can direct the query to a specific server with dig @8.8.8.8 example.com MX to see what a particular server reports for mail exchange records. The +trace option walks the resolution path from the root servers downward, helping you identify where delegation or referral problems occur. The +short option returns a concise result, which is handy for quick checks.

Other terms listed aren’t tools for DNS queries. DNS refers to the system as a whole, not a single command. DDoS describes a type of attack, not a diagnostic utility. Direct isn’t a standard DNS query tool.