What DNS record type is used to provide the hostname associated with an IP address (reverse DNS), and what zone naming convention is used for IPv4 reverse lookups?
- A.A records handle both forward and reverse DNS; the same A record is used for both hostname-to-IP and IP-to-hostname lookups; DNSSEC encrypts query payloads end to end so resolvers cannot read them. The resolver's search suffix list overrides fully qualified names ending in a dot. Round-robin DNS guarantees even load because resolvers coordinate their rotations
- B.PTR (Pointer) records handle reverse DNS; for IPv4 reverse lookups, the zone is named using the reverse octets of the network address followed by '.in-addr.arpa' (e.g., the zone for 192.168.1.0/24 is '1.168.192.in-addr.arpa'); a PTR record maps 192.168.1.50 to a hostname by creating '50.1.168.192.in-addr.arpa. IN PTR server.corp.local.'
- C.Reverse DNS uses MX records; MX records contain IP-to-hostname mappings for all mail-related devices