IPv6 Core Protocols Implementation

2 IPv6 Addressing Architecture

2.1 Introduction

The most well-known and important enhancement introduced by IPv6 is the expansion of the address space as the result of increased bit allocation for an IPv6 address, that is, from 32 bits in IPv4 to 128 bits in IPv6. The IPv6 address architecture also introduces several remarkable characteristics along with the enlarged address space, mainly from operational experience with IPv4.

First, IPv6 has an explicit notion of address scopes, with which the uniqueness and usage of an address is limited to some area of the entire Internet. Whereas limited scoped addresses are used in IPv4 multicasting as an operational technique and IPv4 private addresses used with Network Address Translators can be regarded ...