How to point to new DNS server IP?

[Kevin Darcy]

Roy Arends wrote:

> On Tue, 3 Jul 2001, uunet wrote:
>
> > Hi,
> >       We are going to change our ISP, this mean that we are going to get new
> > network IP range. Then we need to change all our DNS entries and change the
> > nameserver name/ip  for all of our web sites at the Network Solutions. I
> > have to move our DNS/Web servers from my old ISP to new ISP. What is the
> > easiest way to do this? I mean with minimum downtime and making my websites
> > available for most of the time. How shold I proceed, change the name server
> > address first or move the servers first?
> >
> > Thank You
> > Babu.
>
> 1) copy your old zone to the new ISP's machine.
> 2) Change the NS records in your zone so they point to the new ISP's
>    machine.

> 3) Request Network Solutions to change the delegation NS records so they
>    point to the new ISP's machine.
>
> When the TTL has expired from your old delegation, i.e. say the delegation
> NS records have a TTL of 2 days, you can:
>
> 4) After 2 days (!!!!!!) request the old ISP to remove the zone from their
>    servers.
>
> note that the TTL issue is very important to make sure that your zone is
> available to resolvers.

Note also that any changes you make to the zone between steps #2 and #4 need to
be made in parallel to both the old and new servers, since there's no telling
which set of servers will answer any given query for any given external resolver.
If at all possible, it is best to just freeze all changes to the zone during this
transition period.


- Kevin