Concise Guide to DNS and BIND, The

Split DNS, NAT, and Network Hiding

Many companies don't want to share the complete DNS information for their internal network with the world for security reasons. Another reason is that they might be using a NATing Internet gateway and that the complete DNS information contains hosts with IP numbers that are not routable over the Internet. So, they make this DNS information unavailable from the outside. But, they still want some hosts to be seen and used by the outside. They therefore provide that DNS information to the world.

The network management principle is known as network hiding, and the accompanying DNS configuration is known as split DNS. Many will argue that network hiding is an exercise in futility, that scores of things cross over ...