CompTIA A+ Core 2 (220-1202)Operating SystemsMedium
A technician is troubleshooting network connectivity on a Linux server. The server is unable to reach resources on the internet but can communicate with other devices on its local subnet. The technician suspects a DNS resolution issue. Which command-line utility should they use to verify DNS resolution for a specific domain?
- Anslookup google.com
- Bifconfig
- Cping google.com
- Dip addr
Show answer & explanationAnswer & explanation
Correct answer: A. nslookup google.com
The nslookup command is specifically designed to query Domain Name System (DNS) servers and obtain domain name or IP address mapping information, making it ideal for diagnosing DNS resolution issues.
Why the other options are wrong
- B. ifconfig displays network interface configuration (legacy), not DNS resolution.
- C. ping tests reachability by sending ICMP packets, but doesn't isolate DNS issues from network path issues.
- D. ip addr displays network interface configuration, not DNS resolution.
nslookup (Linux)
A command-line tool used to query the Domain Name System (DNS) to obtain domain name or IP address mapping or for any other specific DNS record.
- Useful for diagnosing DNS resolution problems.
- Can specify a particular DNS server to query.
- Provides information on A records, MX records, NS records, etc.
Memory trick: Network Services Look Up Domain Names for Solutions.