I host my own multiple Websites on my server. How do i setup my own child nameserver?
There are 4 different websites, with .com and .net and .ro at the end. I moved them to my own server.
My Domain Administration (Registrar) let's me define my own child nameserver with my own IP and i've added my nameserver as my domain nameservers list.
ns.something.ro as the first and only in the nameservers list
ns.something.ro with my own IP address as the child nameserver
I've setup everything and it works (kind of). When i use my ns IP adress directly i can of course access everything. Using "normal" external dnses will not work. As expected others on the web can't resolve correctly.
What's wrong? Am i missing something?
If you are just doing web sites consider just defining www.example.com using your registrar's servers. For simple configurations, this is the simplest option.
If your IP address is not static, you will need to use a dynamic DNS service for one of your names. Use CNAME definitions yo point all your other names to the one handled by the dynamic DNS service.
If you have a static address and don't want to use your registrar's servers, you will need to learn how to configure and secure a nameserver like bind. This would likely include a split configuration for inside your network and outside your network. You should also arrange for at least one backup nameserver.
For inside your own network it is common to require different IP addresses than are visible from the Internet. For this to work you need to use your own DNS servers on your network. On Linux systems I use DNSmasq to supply local addresses from cache, and external address from the Internet DNS. I also run a split bind configuration which serves only my domains to the Internet, and acts as a caching nameserver for my DMZ.
In order for DNS to work properly world-wide the name-server specified in the SOA record and any NS records for a domain has to be on public IP addresses and reachable by the general Internet. Additionally, if you're using nameserver names within the domain you're setting (such as you're doing) glue records have to be entered in the parent registry's DNS.
You don't have to do this if the nameserver you configure is NOT in your domain. This is easier to deal with, and you don't have to make sure your parent domain's glue records are updated.
And finally, if you have a few hosts, it is entirely possible to define your subdomain records as A records in your parent domain's DNS if such is allowed.