Roll DNS changes with TTL strategy
Lower TTL, dual-publish, cut over, then raise TTL again.
Objective
Manage DNS changes safely
Plan TTL reductions, dual-publish windows, and cutovers for mail-critical DNS.
Starting state
A mail-critical DNS change is planned
Prerequisites
- Current TTL known
- Change window scheduled
Estimated time
2–4 hours
Difficulty
advanced
Required access
- DNS zone edit rights
Inputs
- Records to change
- Target TTL values
- Rollback plan
Step-by-step instructions
- Lower TTL in advanceReduce TTL and wait for prior cache expiry.
- Publish new recordsApply the cutover RRset at the authority.
- Observe then raise TTLConfirm success, then restore longer TTL values.
Verification
- Recursive and authoritative views converge
Common mistakes
- Mixed answers persist beyond planned window
- How long to keep reduced TTL after cutover
Rollback / recovery
- Republish prior RRset; keep low TTL until stable
Expected outcome
DNS change completes with bounded mixed-cache risk.
When to escalate
- Mail flow disruption during cutover