Abstract Due to recent concerns over the impending depletion of the current pool of Internet addresses and the desire to provide additional functionality for modern devices, an upgrade of the current version of the Internet Protocol (IP), called IPv4, is in the process of standardization. This new version, called IP Version 6 (IPv6), resolves unanticipated IPv4 design issues and takes the Internet into the 21st Century. This paper describes the problems of the IPv4 Internet and how they are solved by IPv6, IPv6 addressing, the new IPv6 header and its extensions, the IPv6 replacements for the Internet Control Message Protocol (ICMP) and Internet Group Management Protocol (IGMP), neighboring node interaction, and IPv6 address autoconfiguration. This paper provides a foundation of Internet standards-based IPv6 concepts and is intended for network engineers and support professionals who are already familiar with basic networking concepts and TCP/IP...