CompTIA Network+ Practice Test

Which type of DNS server contains zone information that is read-only?

1. Primary DNS server

2. Secondary DNS server

3. Local DNS server

4. Authoritative DNS server

The correct answer is: Secondary DNS server

The correct answer pertains to the nature of how zone information is managed on DNS servers. A secondary DNS server is typically a read-only server that gets its zone information by receiving a zone transfer from a primary DNS server. In this setup, the primary server holds the original read-write zone data, whereas the secondary server maintains a copy of that data, which cannot be modified directly on the secondary server itself. This read-only characteristic is essential for maintaining consistency and integrity in DNS records across different servers, ensuring that all queries to the secondary server return the same information that is managed by the primary server. The secondary server can respond to DNS queries, but any updates or modifications must be made on the primary server and then propagated to the secondary server. In contrast, primary DNS servers have the capacity to modify their zone data, and local DNS servers often operate in a caching role rather than holding persistent zone records. Authoritative DNS servers can refer to both primary and secondary servers; however, the distinction of read-only applies specifically to secondary DNS servers wherein the zone data is not subject to changes made directly on that server.