<seconds>.<token>.ttl.dnsp.co
You set the lifetime. We report whether it was respected.
What it does
Every DNS answer carries a TTL, the number of seconds it may be cached before it has to be looked up again. It is what decides how quickly a change to a record takes effect, and a resolver that caches past the TTL will keep handing out an address after it has been changed.
Ask for <seconds>.<token>.ttl.dnsp.co. The seconds value is the TTL you want us to attach, and the token is any label you have not used before. The address we return changes every time we are genuinely asked, so if the answer stays the same for longer than the TTL you requested, something in the path is holding it past its expiry.
Example
Reading the answer
The lifetime is honoured.
Something is serving the record after its expiry.
Correct. Caching inside the lifetime is exactly what a TTL permits.
Normal. The countdown tells you how much longer the cache will keep it.
Notes
- Seconds is the first label, token is the second: 5.mytoken.ttl.dnsp.co asks for a 5 second lifetime.
- Use a token nobody else is using, otherwise you are watching someone else's queries refresh the record.
- Change the token to start over with a clean record rather than waiting out a long TTL.
- Aim it through your resolver. Asked directly there is no cache in the path to test.