How to spread a zone on two DNS servers?

Question

Domain Name System

There is a DNS zone. I would like to raise a new DNS server without the ability to import the zone from the old DNS server. The reasons are different, but the point is that all records will have to be transferred by hand for some long time.
I would like to keep the old DNS server and have a new DNS server with the same zone, but it will be filled gradually. As records are transferred to the new DNS, they will be removed from the old one.
Can you please tell me how to implement such a scenario?

Answer 1

we calmly form a dns zone on the new server without deleting records from the old
one when everything is ready, on the old and new we indicate the address of the new server in the NS records, while leaving the old one in operation for a day or two (during this time all clients will know that dns server has changed). after 2 days, disable dns on the old one.
Everything, all requests are handled by the new