The IP addresses for our ns2service.net DNS servers have changed today.
NS2service.net users will need to ensure that their primary DNS server's configuration accepts zone transfer requests from the new IP addresses (e-mail sent directly with this / available when logged into our website).
Note that our servers are still handling your DNS requests, but if your primary DNS server is configured to only accept zone transfer requests from the specific IP addresses of our secondary DNS servers, any changes to your zones (on your primary DNS server), will not appear on our (secondary) DNS servers until you allow zone transfer requests from the new IP addresses.
Alternatively (and recommended) you can limit zone transfer requests using TSIG signatures. This way you don't need to worry about changes to secondary DNS server IP addresses.
We did this (changed the IP addresses) because of an incident at our previous data center (Microsoft Azure) which forced a change of the IP address on one of our servers. Rather than just using the new IP address at Microsoft Azure, we decided to move all our DNS servers to Amazon AWS.
Amazon AWS has a different concept around IP addresses ("Elastic IP"), which should ensure that, going forward, we can continue using the same IP addresses even if we decide swap out servers, switch operating systems, etc.