CompTIA Network+ Practice Test 2025 - Free Network+ Practice Questions and Exam Prep Guide

The TTL, or Time to Live, setting on an authoritative DNS server indicates the duration for which the DNS records can be cached by resolvers or other DNS servers before they must be refreshed by querying the authoritative server again. Essentially, it tells the cache how long to consider the DNS response as valid. A longer TTL reduces the number of queries to the authoritative server but may lead to stale data being used longer, while a shorter TTL allows changes in DNS records to propagate more quickly, at the cost of increased traffic to the server.

The other options do not correctly describe the function of the TTL setting. The number of queries processed pertains more to server performance metrics rather than caching behavior. The level of server authorization is related to whether a server is authoritative for a particular zone, but not to TTL settings. The maximum zone information size is related to the total data that can be stored in a zone file, but again, does not pertain to how long that information can be cached. The focus of the TTL is strictly on cache validity duration.