This redbook provides an introduction as well as a reference to the Transmission Control Protocol/Internet Protocol (TCP/IP) suite of protocols and applications, which provide the foundation and framework for many computer networks, among them the world's largest, the Internet. This redbook explains the basics of TCP/IP and also includes an overview of the latest developments in the world of TCP/IP and the Internet. Special areas of interest are security (IPSec, VPN, certificate and key management, etc.), Java, IP mobility and address management, multicasting, priority and bandwidth reservation, IPv6, directory protocols and, last but not least, the latest hardware and software developments.