DNS Time to Live (TTL) is the duration in seconds that DNS resolvers and browsers cache your record before querying authoritative servers for an update. Because DNS caching isn’t retroactive, updating a CNAME record while a high TTL is active causes traffic to switch over unpredictably and delays emergency rollbacks. Lowering your TTL in advance enables a fast global cutover and provides a short emergency rollback window.

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Make sure you lower TTL in advance before cutting over a site with existing traffic. The change only takes effect globally after one full duration of your current TTL. If your hostnames don't serve traffic yet, you don't need to wait. See If your hostname doesn't serve traffic yet.

If your hostname serves live traffic

1. Before the planned cutover, in your DNS management system, edit your existing DNS record. Set the TTL to 300 seconds (or 60 seconds for a tighter window). Don’t update the CNAME target yet.
2. Wait at least as long as your previous TTL (for example 24 hours for an 86,400s TTL) so that all global resolvers expire old cached values and adopt the new 5-minute TTL.
3. Confirm the new TTL applies. Query your hostname against a public resolver and check the TTL in the answer. If it still reports the old value, resolvers haven't finished expiring their caches, and you need to wait longer before you cut over.

If your hostname doesn't serve traffic yet

A hostname that has never resolved isn't cached anywhere, so there's no old TTL you need to wait out. You can proceed and create the CNAME record directly, with two things in mind:

• Set the TTL to 300 seconds for the launch window rather than your target value. If necessary, this will let you correct the edge hostname or change its security level within minutes instead of hours.
• Check your zone for a wildcard record. If a wildcard such as *.example.com exists, your hostname already resolves through it and that answer is cached under the wildcard's TTL. Treat it as an existing record and follow the steps in If your hostname serves live traffic.

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Avoid querying the hostname before you create it. Resolvers cache negative (NXDOMAIN) answers for a duration set by your zone's SOA record, typically minutes to a few hours, and you can't shorten that retroactively.

Next steps

After resolvers adopt the new short TTL, update your DNS CNAME record to point traffic to Akamai. Keep the short TTL in place for as long as you want a fast rollback available. See Back out of edge network. Once traffic routes stably through Akamai, raise the TTL back to your standard value.