What is the purpose of a PTR Record?

What is the purpose of a PTR Record?

• A. Used for reverse DNS lookups, mapping an IP address back to a domain name.
• B. Used to rotate keys for DNSSEC.
• C. Used to designate the primary DNS server for a domain.
• D. Used to specify mail routing policies.

Answer: (A)

PTR records are used for reverse DNS lookups, mapping an IP address back to a domain name. This helps verify which domain is tied to an IP, aids in troubleshooting, and is commonly used by mail servers and logging systems to determine the domain associated with an address. PTR records live in the reverse DNS space (IPv4 uses in-addr.arpa, IPv6 uses ip6.arpa). The other options describe DNSSEC key rotation, NS records for designating the primary DNS server, and MX-like mechanisms for mail routing, none of which are functions of PTR records.

PTR records are used for reverse DNS lookups, mapping an IP address back to a domain name. This helps verify which domain is tied to an IP, aids in troubleshooting, and is commonly used by mail servers and logging systems to determine the domain associated with an address. PTR records live in the reverse DNS space (IPv4 uses in-addr.arpa, IPv6 uses ip6.arpa). The other options describe DNSSEC key rotation, NS records for designating the primary DNS server, and MX-like mechanisms for mail routing, none of which are functions of PTR records.