Time-to-live (TTL) values affect how quickly DNS changes propagate—and how much load you place on resolvers.
Lower TTLs speed up cutovers after incidents or migrations but increase query volume. Higher TTLs reduce resolver chatter yet slow rollback when something breaks.
Practical defaults
- Stable records: 15–60 minutes for apex and mail exchangers.
- During migrations: temporarily lower to 300 seconds 24–48 hours before the change, then restore.
- CDN / failover aliases: follow your provider’s recommendation (often 300–900 seconds).
Document who may change DNS, attach approvals for apex edits, and verify propagation from multiple regions before closing a change ticket.