[CentOS] Replacing Multiple Servers with One

Vipul Agarwal
2013-03-06T17:14:17Z

On Wed, Mar 6, 2013 at 4:40 PM, Tim Evans <tkevans at tkevans.com> wrote:

> We are replacing four servers, running mail, web, ftp, and dns,
> respectively, with a single server to run all four services.
>
> The new server will have a new IP address.
>
> It seems fairly straightforward to redirect mail, web, and ftp services
> to the new server via DNS CNAMES, but I'm not quite sure about how to
do
> the change for the DNS service itself.
>
> Is there a need to maintain the old DNS server's IP address during a
> transition, or longer? Via a virtual IP with the old DNS server's IP
> address on the new machine, perhaps? Or a second NIC with the old
> address? Or just have the router redirect incoming DNS requests?
>
> Thanks.
> --
> Tim Evans                       |   5 Chestnut Court
> Linux/UNIX Consulting           |   Owings Mills, MD 21117
> http://www.tkevans.com/         |   443-394-3864
> tkevans at tkevans.com
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Hi Tim,

To migrate the DNS server, ideally the steps as follows,

   - Provision the new server and setup as the secondary DNS server
   - Sync the zones
   - Reduce the TTL of the nameservers
   - Change the new server to primary
   - Change the glue DNS records (from domain registrar panel - if
   applicable)
   - Let the old server running for few days and monitor for any traffic

Regards,
Vipul