My problem is that I am trying to set my domain's nameservers to the nameservers of my dedicated server.

My domain is hosted by Namecheap, and everytime I try to input the two nameservers for my private server, one of them is rejected for being unregistered.

My dedicated server's control panel is managed through Parallels Plesk 11.5, and the nameservers provided to me are one from the actual provider, OVH (sdns1.ovh.ca), and the other is an actual unique nameserver that points directly to my specific dedicated server.

Previously, for another domain I own, I was successfully able to get Namecheap to take the nameserver without an error, so I know this is possible. I know that it works for one of my other domains.

After being redirected by Namecheap to contact the server provider, I called OVH and they said it was something I would have to do myself.

One interesting detail the OVH representative mentioned was that he saw that my port 53 was closed, which is the port that handles DNS. The only problem is that I have no idea or knowledge as how to open this port back up.

So, my final question is how can I get this nameserver working in Namecheap to point to my dedicated server?

If you need any more details, feel free to ask for clarification.