Linux Essentials (010-160) — Question 78

Reverse DNS assigns hostnames to IP addresses. How is the name of the IP address 198.51.100.165 stored on a DNS server?

Answer options

• A. In the A record for 165.100.51.198.ipv4.arpa.
• B. In the PTR record for 165.100.51.198.in-addr.arpa.
• C. In the RNAME record for 198-51-100-165.rev.arpa.
• D. In the ARPA record for 165.100.51.198.rev.
• E. In the REV record for arpa.in-addr.198.51.100.165.

Correct answer: B

Explanation

The correct answer is B, as the PTR record is specifically used for reverse DNS lookups, mapping an IP address to its corresponding hostname. Option A is incorrect because A records are used for forward lookups. Options C, D, and E mention incorrect record types or formats that do not conform to how reverse DNS is structured.