DNS forwarding

Hi,

A customer have an dedicated server and register a domainname on my DNS server.
I put into MY dns the A records:
ns1.domain.net. a xxx.xxx.xxx.xxx
ns2.domain.net. a xxx.xxx.xxx.xxx

On his server I add the domain: domain.net
Into resellers aria I select his 2 IP`s and set for that domain the nameservers.

Other registered domainnames we give HIS DNS nameservers but doesent resolve.
DNSreport see the nameservers off the dedicated box but can`t get contact: A timeout occurred getting the NS records from your nameservers! None of your nameservers responded fast enough. They are probably down or unreachable. I can't continue since your nameservers aren't responding.
If I visit: http://ns1.domain.net I get access to this page.

Where can I find the error?
Thanks for any advice

Delataned,

If you'd like help please use real domain and IP# info.

You may think you're doing something in the way of security but all you're doing is obfuscating the problem.

DNS is the world's largest public distributed database; you're not hiding anything but our opportunity to help you.

Please repost with real information.

What domain name are the nameservers running on?

Are the IP#s for those nameservers on your server, or on your client's server?

Let's start with these questions and see if we can help you.

Jeff