I fail how to understand how changing IP addresses leaves DNS out. But I
will try to guess; you have a network consultant who maintains your DNS
and he only works on your site on the second Thursday of the month. You
want to bring this system up on the first Saturday and can't afford the
wait. If this is the case ask him how to do it yourself or get him in on
your demand (or replace him).
We change our DNS entry for our system once a quarter for a weekend and
then change it back. Part of our Mimix switch process from one machine to