Private nameservers are just custom DNS and HOST records that point to our DNS Cluster IPs. These will not be a 'separate' set of servers nor will you use IP addresses that are different from those provided to you in your "New Account Information" email. This allows you to give your clients a set of nameservers that are specific to your company and non-generic in nature. We do also provide you a generic set of nameservers that you are welcome to use should you not wish to set up private nameservers.
Depending on what registrar you used for your domain name you may be able to set up your private nameservers on your own or you may have to contact your registrar to have them set up for you. Generally your registrar will list this feature as "Host Records", "Child Nameservers", or "Private Nameservers". If you do not see the option in your domain control panel you will want to get with your registrar for support.
If the domain was registered through us, you can follow the directions in "Setting up Private Nameservers on a domain registered with MDDHosting"
If you need any assistance setting up your private nameservers please submit a support ticket and include which domain registrar you are using and we will do our best to help you get them set up. In some cases your domain registrar will need to make the changes in which case you will need to contact them and ask them to do it for you.
The IP addresses used to set up your private nameservers can be found in your Reseller Account Information.