DNS Change Day Checklist: How to Avoid Traffic Loss

DNS cutovers look simple and fail quietly. A single record mistake can send traffic to the wrong origin, break SSL, or split users across old and new infrastructure.

Use this checklist to make DNS change day predictable instead of stressful.

Before the cutover

• Lower TTL values 24-48 hours in advance
• Export and back up existing DNS zone records
• Verify target origin health and certificates
• Prepare rollback records and owner contacts
• Schedule monitoring windows around propagation

During the cutover

Monitor DNS resolution from multiple regions and networks. Confirm the domain resolves to expected targets everywhere.

Track HTTP status, redirect behavior, and certificate validity as records propagate.

After the cutover

Watch conversion-critical paths for at least 24 hours. Propagation edge cases can appear long after initial success checks.

Compare traffic, errors, and conversion rates against pre-change baselines.

Common DNS migration traps

Missing CAA records, incorrect CNAME flattening behavior, and stale AAAA records frequently cause partial outages.

Keep a checklist item for each record type your stack depends on.

Escalation triggers

Set explicit triggers for rollback, like failed TLS checks across multiple probes or conversion drops beyond threshold.