Which DNS record indicates the Start of Authority and contains zone administrative information?

• A. NS
• B. A
• C. MX
• D. SOA

Answer: (D)

The Start of Authority (SOA) record is the authoritative source for a DNS zone and carries its administrative details. It designates the primary name server for the zone and includes important zone management information such as the zone administrator’s contact, the zone’s serial number, and timing parameters (refresh, retry, expire, and minimum TTL). These fields govern how secondary DNS servers refresh data and how long cached records remain valid, ensuring consistent updates across the zone. That’s why this record is the one that contains zone administrative information.

Other records have different purposes: NS records list the authoritative name servers for the zone, but do not hold administrative details; A records map hostnames to IPv4 addresses; MX records specify which mail servers handle email for the domain.