Which statement best describes the purpose of a zone transfer in DNS?

• A. They decrypt DNS traffic for monitoring.
• B. They replicate DNS records from a primary DNS server to a secondary DNS server.
• C. They assign IP addresses dynamically.
• D. They configure firewall rules.

Answer: (B)

Zone transfer is the process of keeping DNS data consistent by copying the zone records from a primary DNS server to one or more secondary servers. This replication ensures that if the primary server is down, queries can still be answered by the secondary servers, and it helps distribute the load by allowing multiple servers to answer for the same zone. Transfers typically happen as full or incremental copies of the zone data (AXFR or IXFR) over TCP, and they can be secured to prevent unauthorized access.

The other options describe unrelated functions: decrypting DNS traffic for monitoring doesn’t affect DNS data replication, dynamic IP assignment is handled by DHCP, and firewall rule configuration is about network access control rather than DNS data synchronization.