In a Simple Network

The basic principle you'll rely on is that a DNS server that receives a query will answer the query if it knows the answer. Thus, by merely setting up BIND with your zone and no root.hints, you have a working DNS service your DNS clients can use. The normal root.hints file is, of course, useless inside your closed network. For redundancy, you then can set up secondary servers for your zone in the normal manner, but also without a root.hints file. In a simple scenario in a simple company, this is all you must do.

Harmless Error Messages

When you drop the root.hints file, you get errors about it being missing and messages such as sysquery: nlookup error on ?. These are all harmless and can be safely ignored.

If you're not alone on your network and other people control other parts of the network, you should probably have several zones so that each network administrator can take care of her own zone, which will help expedite things. In that case, you still might not need any rootservers as long as all your DNS servers are authoritative for all the zones in your network, they are masters or slaves for all the zones, or they have NS records for any subzones in your domains.

So, using our previous Bouvet scenario, a simple network of slaves and masters would be set up, they would all be authoritative for each other's zones, and all names would be available from all nameservers at all times.