Re: root servers (URGENT)
Web search "get list of root servers with dig".
But it is not clear what you are trying to do. If you want to resolve your own private names or IPs, you should configure your nameserver(s) with "proper" zone files to resolve whatever non-public names to IPs or IPs to names (reverse lookup). Then your nameserver(s) will use themselves for whatever zones they have, and public DNS for anything else. If you have multiple nameservers "properly" configured with one as master and other(s) as slaves, any updates to the master will propagate to any slaves.
i5 650 3.2 GHz, 8 GB, nvidia GTX 550 Ti 32" 1080p | i7-4700, 8 GB, Intel HD 4600/nvidia GTX 765M 15.6" 1080p | etc.