> The old cached DNS entries in DNS resolvers simply expire, in an arbitrary order. I really wish that was so. There's lots of weird resolvers out there used

> The old cached DNS entries in DNS resolvers simply expire, in an arbitrary order. I really wish that was so. There's lots of weird resolvers out there used by weird ISPs that don't properly respect the TTL value. Setting TTL to some really low number a full day before making a major change is no guarantee that your zone will expire in a bunch of places. All kinds of weird ISPs try to do things with the dns results they present to their customers.