What is the definition of a zone transfer in DNS?

• A. A process that transfers all zone information maintained by a DNS server.
• B. A method to query DNS servers for records.
• C. A technique to cache DNS records on clients.
• D. A security feature to replicate DNS zones only within local network.

Answer: (A)

Zone transfer is the process by which DNS servers copy and replicate the entire set of records in a zone from a primary server to secondary servers. This keeps multiple servers in sync so queries can be served even if the primary is down. It can be a full transfer (transferring all records) or an incremental one that sends only changes. This concept is why the correct choice describes transferring all zone information maintained by a DNS server.

The other options don’t fit: querying DNS servers for records is just a lookup, not replication; caching stores resolved results on clients, not the zone data itself; and zone transfer is not a security feature nor limited to a local network.