My company is the Maintainer for at least one second level domain like example.com. The previous sysadmin created a GNU/Linux Bind9 DNS server running on a public IP address x.x.x.x which resolves "public" dns queries for that domain. Now we are migrating from one ISP to another and our public IP address will soon change in something like y.y.y.y. I think we will loose our DNS reachability. How can I avoid this? We also run a mail server inside our network and we don't want to loose mail server reachability.
How can I change the Bind9 DNS server IP? What's the technical procedure to do that? We are not Registrant but only Maintainers
Thank you in advance for your help