> -----Original Message----- > From: centos-bounces at centos.org [mailto:centos-bounces at centos.org] On > Behalf Of Vipul Agarwal > Sent: Wednesday, March 06, 2013 12:14 PM > To: CentOS mailing list > Subject: Re: [CentOS] Replacing Multiple Servers with One > > 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 > > _______________________________________________ > > CentOS mailing list > > CentOS at centos.org > > http://lists.centos.org/mailman/listinfo/centos > > > > 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 > _______________________________________________ Also, if you want to be really safe, you could set the old server to forward requests to the new one via a redirect in apache, in the mailertable (if using sendmail), and change the welcome message on old ftp server to use the new one until DNS propogates.