On 13-Dec-2005, at 16:28, Steven M. Bellovin wrote:
In message <9828b780512131312q220a5ea6x97a6167e33c654a0@mail.gmail.com>, Sam Cr ooks writes:
I would think you would want to drop your DNS record TTLs for all domains being moved to something very low several days before the switch-over period.
More precisely, you want to change the TTL on the NS records, which are in the parent zone. If you're keeping the name but changing the address, worry about the A records, too.
You also want to check all the registries which are superordinate to zones your server is authoritative for, and check that any IP addresses stored in those registries for your nameserver are updated, otherwise you will experience either immediate or future glue madness. A conservative approach to this kind of transition is to arrange for your nameserver (or different nameservers hosting the same data) to respond on both the old and new addresses, and to continue in that mode until you see no queries directed at the old address for some safe-seeming interval (bearing in mind TTLs and cached records, alluded to by Steven and Sam). Joe