I am changing server and I have been using my own nameservers for all my domains, these nameservers have the same ip on both ns1. and ns2. (i only had the main server ip when i set it up), now I have to change the nameservers ip for the new server and I have a few doubts.
What happen if I only set the new ip in ns1. but let ns2. with the old server ip?
Should I use different ips (both from the new server) on ns1. and ns2.? Whats the benefit if any?
You're supposed to have two IP addresses because you're using two servers for redundancy (master and slave nameservers). If you are putting both IPs on the same machine, there's very little redundancy from using two IP addresses (sure, it's possibly you could just lose one IP, but very unlikely) so it doesn't matter.
Using one (and not two) nameserver is usually OK. Using the IP of a wrong or non-existant nameserver spells trouble, even if it's only for the 2nd NS.
