[H-GEN] DNS Question for the DNS Gurus

[Rick Phillips]

I have a web/mailserver running with a number of virtual domains.  I am
about to change my ISP after a number of years and will be "churning"
the account.  This means that sometime on the nominated day, a Telstra
technician makes a change in the exchange.  The new ISP can only
guarantee that it will be done some time on the day nominated.

As I cannot afford to be off the air for too long and because
re-delegation can take up to 24 hours, does anyone know if I can have my
backup DNS server (on another machine and on another ISP) be changed to
point to my new address while my own DNS server points to my current
address.

The theory is that when the changeover happens, the new IP address will
be available to the world immediately off the backup server.  My own DNS
server can be changed after the event to match.  Would this work?

Regards,

Rick Phillips