Internal Rootservers and the Internet
A thing you must consider is reserving the domain name you want to use with the appropriate Internet name authority. If you connect to the Internet or use it to exchange email or other documents, you—and those with whom you communicate—can use your reserved name in all contexts, eliminating any need to duct-tape together things with mismatched naming schemes. Reserving a domain is discussed in Chapter 4, "Getting a Domain."
Implementing internal rootservers is a good option if one of the following is true: Your organization is somewhat complex; you want to use several TLDs internally because your organization is international; you want to use several TLDs internally because your organization ...