External name servers provide two important services to a corporate network: Resolving Internet domain names, usually on behalf of internal resolvers and name servers; and answering queries about the company’s domain names for name servers on the Internet. The former role is critical to accessing web sites, sending electronic mail, and just about any other use of the Internet by the company and its employees. The latter role is necessary to the company’s conducting business on the Internet, for access to the company’s web site, for inbound electronic mail delivery, and more. In well-designed DNS architectures, these roles are split between two sets of external name servers. In this paper, I’ll refer to the name servers that assist in the resolution of Internet domain names as “forwarders,” and to the name servers that answer queries about the company’s domain names as “authoritative name servers.”