So I am making the change between Server A and Server B for cost reasons, and have changed the IP's of my nameservers to reflect this. I have also moved my dns records across to my new server. What has happened over about 12 hours is the changeover has happened between my old IP (Server A's) to being resolved as nothing (no IP listed) using https://www.whatsmydns.net and my browser. My understanding was that it would change at some point over the 48 hours instantly from A to B, not to nothing in between. Is this normal or have I broken something?
A simple checklist of what I would try:
- Double check that the DNS server itself is available and you have the correct nameserver/IP combinations.
- That DNS is working and responding on the proper ports (53 and perhaps 953).
Try using a tool like dig to verify what DNS records are actually being returned, especially for a given third party e.g Google Public DNS:
dig @220.127.116.11 NS example.com
Test your site connection on a separate network. It seems unlikely to reveal much in this instance but I have found it good practice on principle.
Also, since you mentioned transferring records, I would double check these. Particularly, I would update the serial, double check any SOA/NS entries generally and might adjust TTLs, etc. as appropriate.