Here's the lowdown: our VPS vendor doesn't own its own nameservers (NS), whereas the domain registrar does. We're rocking VESTA as our VPS panel of choice. We've got a single IP address to work with.

We've added a domain to the VESTA panel and registered it with the registrar, specifying:

A record for '@' pointing to the IPvPS
CNAME record for 'www' pointing to IPvPS
In the VESTA panel, we can manage NS records, including standard ones, A records, mail, and IP addresses. However, we've removed the NS1 and NS2 records, leaving only the SOA record pointing to NS1.localhost.ltd.

So, the burning question is: what NS records need to be added at the registrar and in the VESTA panel to get our three domains up and running on the VPS?

Consider using a DNS service provider like Cloudflare for better performance and security, and add their NS records at your registrar and VESTa panel:

Registrar: Update NS1, NS2, NS3, NS4 with Cloudflare's NS1, NS2, NS3, NS4
VESTa panel: Keep the existing NS records, but add A records for '@' and 'www' pointing to your VPS IP address, and ensure your Cloudflare settings are properly configured

I'd recommend updating your DNS settings by modifying your nameservers at the registrar. If you're looking for a reliable solution, Namecheap's FreeDNS service is worth checking out - just keep in mind that you'll need to be proficient in English. Additionally, it's essential to grasp the fundamentals of DNS and its associated theories to ensure a seamless online experience.

In the vast majority of situations, domain registrars/specialized services provide geo-distributed nameservers, ensuring that even if one region experiences a network outage, the remaining nameservers will continue to function, allowing your website to resolve.

Notwithstanding, if the specific area where your server resides experiences a network failure, it won't be able to resolve the website address.