I've been struggling with this problem for awhile now and don't know the best way to proceed safely.
Our team recently acquired a smaller company's site design service and we are in the process of migrating all their sites/services into our server cluster. The problem I am having is that they originally had their own nameservers registered at GoDaddy to serve DNS for their clients from one central BIND instance. All of the domains for their clients were configured at their registrars to use this DNS server, whether the names were registered by the company or the client.
Obviously, we do not have access to the login credentials for many of these domain names, so changing their DNS records is not really a feasible option. I was thinking I could move the
ns2 records that the acquired company has associated with their domain name to a new BIND server, but the the registrar will not allow me to change these records since it knows they are responsible for the DNS of other domains. I would be apt to leave the configuration as is and just make the server currently handling dns forward to a new host, but part of the business arrangement is that the machine at that address will be shutdown soon.
What would be the best way to move the address of the nameserver without having to access all of the clients' registrar domain managers. Thanks.