ABSTRACT
The nodes and pipes that make up cyberspace must be able to talk to each other so the rules for interaction, the protocols such as Internet Protocol (IP) and Transmission Control Protocol, make this possible. Cyberspace is a dynamic system, particularly because systems near the edges come and go. Traffic to and from Domain Name Service (DNS) servers uses User Datagram Protocol, but this traffic is invisible to users—it is embedded in web browsers, mailers, and other applications that need to resolve names to IP addresses. In other words, authoritative DNS servers hold the definitive mapping between a domain name and an IP address while lower-level DNS servers hold copies of such a mapping. In organizations where security is paramount, computers may have their entire software and systems reloaded every day.
