The TTL for negative caching is pas arbitrary. C'est taken depuis le SOA record at le top of le zone to qui le requested record would have belonged, had it existed. Par exemple:
example.org. IN SOA master-ns1.example.org. Hostmaster.example.org. (
2012091201 43200 1800 1209600 86400 )
The dernier value in le SOA record ("86400") is le amount of time clients are asked to cache negative results under example.org..
If a client requests doesnotexist.example.org., it will cache le result for 86400 seconds.
