Practice Quiz

MSCA 70-291 Windows Server 2003 Exam Prep

Category - 70-291

Start a Study Session Sign up for Question of the Day
Your colleague has set the default TTL value for your company’s primary DNS zone to 15 minutes. Which of the following is most likely to occur as a result of this change?
  1. Resource records cached on the primary DNS server will expire after 15 minutes.
  2. Secondary servers will initiate a zone transfer every 15 minutes.
  3. DNS hosts will re-register their records once every 15 minutes.
  4. DNS clients will have to query the server more frequently to resolve names for which the server is authoritative.
Explanation
Answer - D - When the default TTL value is changed to 15 minutes, DNS clients have to query the server more frequently to resolve names for which the server is authoritative.

Key Takeaway: When a caching nameserver queries the authoritative nameserver for a resource record, it caches that record for the time specified by the TTL, or Time To Live. The unit used to specify a TTL is seconds. The default value is 86400 seconds, which is equal to 24 hours.

This value means that if a DNS record was changed, DNS servers around the world could still be showing the old value from their cache for up to 24 hours after the change. Reducing this TTL value can cause heavier loads on an authoritative nameserver, because the cache is refreshed once every 15 minutes.
Previous Next
Was this helpful? Upvote!
Login to contribute your own answer or details
Start a Study Session Sign up for Question of the Day

Top questions

Related questions

Most popular on PracticeQuiz