Foreword
IPv6 has evolved during the last dozen years or so, and the road has not been easy. The process has been driven primarily by the shortage of address space under IPv4, but also by the desire for new applications that don't fit within the older protocol's limitations. The address space crisis has been delayed by several new approaches to IP addressing, the most important of them being CIDR, NAT, and RFC1918 private address space. At the same time, it was clear that these solutions only postponed the inevitable, so efforts began to redesign the IP protocol. These efforts led to IPv6.
Although CIDR, NAT, and private address spaces have been successful, they didn't solve the problem—they only put it off. Today, the Regional Internet Registries have IPv4 address allocation policies that scare away those who would like to get public address space. IPv4 address space has become a scarce resource, and getting a public address block requires too much paperwork and bureaucracy. We can stretch out the IPv4 address space for 5, 10, or 50 years, but if the result is that only a privileged few can get public address space, what's the point?
Enter IPv6. IPv6 provides a clean fix to the fundamental problem: too few bits in the IP address. The increased length of IPv6 addresses means that they can be assigned freely and used comfortably; they're not a scarce resource that needs to be conserved. IPv6 also makes it possible to deploy new types of applications that rely on public address space, ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access