I listed my website in Cloudflare. I got two Name Servers (NS) and tried fetching their IP addresses from some DNS lookup websites. I got disappointed as I received 3 ip addresses for first name server and 3 ip addresses again for the second name server. But my domain registrar usually require one IP address per one Name Server.
A domain registrar shouldn’t require any IP address, as it is the very idea of nameservers to provide hostnames and not IP addresses. It never is clear what those registrars do with these addresses, particularly when they change. Does it break then?
The returned addresses are all valid, so you can probably pick any, but if you are unsure you best clarify this with your registrar and you might also want to ask them about this awkward requirement.
I find the terms “suck” and “disappointed” however very interesting in the context of increased redudancy
It’s worse than “shouldn’t require”, they literally can’t do anything with IP information if they have it. They can’t write it into the TLD zone as glue as the TLD won’t accept it, and even if they could, it would be ignored by the TLD nameservers (and even if it wasn’t, it would also be ignored by any resolver as being out of scope).
Nothing will break when the IPs change as nothing is using the IP in the first place.
Now this isn’t to say a poorly designed UI might not check them, and then ignore them. Although it would be cynical of me to assume, it could even be designed to make moving a domain’s hosting away from the registrar more difficult by asking for and validating unnecessary information. But more likely whoever developed their system didn’t have any technical understanding of what nameservers are and how DNS actually works.
