Which zone file is a read-only copy of the zone data?

Which zone file is a read-only copy of the zone data?

• A. Primary
• B. Cache-only
• C. Forward
• D. Secondary

Answer: (D)

In DNS, a writable authoritative copy is kept on the primary server, and other servers replicate that data. The secondary server holds a read-only replica of the zone data that it receives through zone transfers from the primary. You can query the zone on the secondary, but you can’t edit it there, which is why it’s the read-only copy. A cache-only server doesn’t store a full zone file as a persistent copy; it only caches responses. A forward zone forwards queries to another server instead of providing its own data. So the read-only replica the secondary holds is the correct fit.

In DNS, a writable authoritative copy is kept on the primary server, and other servers replicate that data. The secondary server holds a read-only replica of the zone data that it receives through zone transfers from the primary. You can query the zone on the secondary, but you can’t edit it there, which is why it’s the read-only copy. A cache-only server doesn’t store a full zone file as a persistent copy; it only caches responses. A forward zone forwards queries to another server instead of providing its own data. So the read-only replica the secondary holds is the correct fit.