This book is about running Internet protocol version 6 (IPv6) in heterogeneous environments: Windows, MacOS, FreeBSD, and Linux operating systems with Cisco and Juniper routers. The intent is to present a clear view to those who are running and administering the protocol, so only those details considered necessary are covered. Rather than explaining IPv6 as a self-contained technology, the book focuses on the impact this protocol has on particular aspects of IP networking, such as host configuration, routing, domain name system applications, security, and providing transit services.

Chapter 1 provides an overview. It answers some basic questions: What is IPv6? Why and when should it be used? What are its benefits? IPv6 offers more address space. While IPv4 hosts use the dynamic host configuration protocol to get an address from a server or router, IPv6 adds stateless autoconfiguration as a means for hosts to be configured with an address. I!Pv6 is more efficient than IPv4: the header has a fixed length and is optimized to process up to 64 bits at a time, routers are no longer required to fragment oversized packets, and all broadcasts for discovery functions are replaced by multicasts. After explaining the benefits, the author addresses some myths that surround the new version. IPv6 is not more secure than IPv4, mobility is also supported by IPv4, there is no additional quality of service, and there is no routing improvement. The remainder of the first chapter explains the differences between IPv6, IPv4, internetwork packet exchange, DECnet Phase IV, AppleTalk, open systems interconnection connectionless network protocol (OSI CLNP), and transmission control protocol/IP (TCP/IP).

Chapter 2, “Getting Started,” covers IPv6 addressing and enabling. Three types of addresses are used: unicast, multicast, and anycast. Regular addresses used for one-to-one communication are unicast. The multicast type !represents group addresses and replaces the broadcast from IPv4, so systems not interested in certain information are no longer forced to spend central processing unit (CPU) cycles to receive it. Anycasts are similar to multicasts, only packets are in this case delivered to one system in the group rather than to all of them. The rest of the chapter explains how to enable IPv6 on Windows XP, FreeBSD, Linux, and MacOS.

Chapter 3 deals with tunneling. A tunnel is a mechanism where one protocol is encapsulated into another protocol to be transported through a part of the network where the original protocol is not supported. Tunneling IPv6 in IPv4 is usually done by adding an IPv4 header to the IPv6 packet. Tunnels come in two flavors: automatic and manual. The chapter presents different mechanisms for automatic tunneling: the one that uses IPv4 compatible addresses (simply called automatic tunneling), 6over4, intra-site automatic tunnel addressing protocol (ISATAP), 6to4, !and Teredo. A large part of the chapter is devoted to 6to4, and covers its installation, security, and monitoring. The remainder of this chapter is reserved for the manually configured tunnels.

Chapter 4 speaks about static and dynamic routing with IPv6. Currently, four dynamic routing protocols work with IPv6 (routing information protocol, open shortest path first, intermediate system to intermediate system (IS-IS), and border gateway protocol-4 (BGP-4)). Linux, FreeBSD, and MacOS machines can be turned into full-fledged IPv6 routers by installing the Zebra (Quagga) software.

Chapter 5 covers the domain name system issues.

Chapter 6, “Applications,” looks at application programming interface issues, and then focuses on IPv6 enabled applications. Firefox supports IPv6 in all distributions. Internet Explorer supports IPv6 under Windows; there are some IPv6 Netscape distributions. As for Apple’s Safari, it can be enabled for IPv6 through ter!minal commands.

Chapter 7 covers the transition issues from IPv4 to IPv6: transition planning, application transition scenarios, proxying, transport protocol translation, and network address translation.

Chapter 8 provides a look at the internals. The differences between IPv4 and IPv6 are emphasized: checksums, extension headers, Internet control message protocol version 6, neighbor discovery, stateless address autoconfiguration, address selection, and path maximum transmission unit (MTU) discovery and fragmentation. Then, the dynamic host configuration protocol for IPv6 is presented, followed by a discussion of IPv6 over ethernet, Wi-Fi, Institute of Electrical and Electronics Engineers (IEEE) 1394, and point-to-point protocol.

Chapter 9 discusses security issues, and chapter 10 is about troubleshooting. The last chapter is about providing transit services. There are two appendices and a postscript at the end of the book.