Part 5. IPv6

For decades, the dominant version of the Internet Protocol has been IPv4. Also for decades, however, another version has been slowly gaining adoption: Internet Protocol version 6 (IPv6), the topic of part 5 of this book. As the pool of available IPv4 addresses has all but dried up in recent years, IPv6 adoption has accelerated, and modern network professionals must be familiar with both IPv4 and IPv6.

Chapter 20 starts with a look at IPv6 addresses. We will explore the concepts of global unicast, unique local, link-local, and multicast addresses in IPv6, as well as how to configure them in Cisco IOS. For CCNA students, who have often just become comfortable with IPv4, IPv6 can seem intimidating. But rest assured that they are actually quite similar, with the most significant differences being the address sizes (32 bits for IPv4 versus 128 bits) and representation (decimal versus hexadecimal).

The similarities between IPv4 and IPv6 will become clear when we cover IPv6 routing in chapter 21, which covers familiar IPv4 concepts from an IPv6 perspective: connected and local routes, static route configuration, default routes, floating static routes, and others. The knowledge and skills you acquire in these two chapters are critical for the CCNA exam, but on top of that, they will be invaluable in your journey as a network professional; IPv6 is the future, and its adoption is consistently growing year after year.