Networking Guide
Chapter 6, Configuring the Domain Name Service

Tuning the time-to-live variable

Tuning the time-to-live variable

The Minimum time-to-live assigned to records and to the zone is very important. A high value leads to low network traffic and fast response time, while lower values generate additional traffic but allow faster propagation of changes. A general guideline followed in this chapter is to set the minimum TTL to three days (259200 seconds). If your zone is very stable, consider setting the value even higher.

If you need to propagate changes more quickly, reduce the Minimum TTL several days before making the changes, then restore it to its previous values after making your changes.

Only changes and deletions are affected by the Minimum TTL; additions are governed by the Refresh TTL.