TABLE OF CONTENTS Sections 7.4 through Section 7.6 cover the IPv6 addressing scheme is some detail. The previous subsections introduced some basic concepts on addressing, and these concepts are expanded in this chapter.
The IPv6 addressing scheme is defined in The IPv6 Addressing Architecture specification, IETF RFC 3513, April 2003 [HIN200401] (RFC 3513 obsoletes RFC 2373). The IPv6 Addressing Architecture specification defines the address scope that can be used in an IPv6 implementation and the various configuration architecture guidelines for network designers of the IPv6 address space. Two advantages of IPv6 are that support for multicast is intrinsic (it is required by the specification), and nodes can create link-local addresses during initialization [DRO200301]. Some portions of this discussion are based on [MSD200401].
As we saw in Chapter 1, the IPv6 128-bit address is divided along 16-bit boundaries; each 16-bit block is then converted to a 4-digit hexadecimal number, separated by colons. The resulting representation is called colon-hexadecimal. This is in contrast to the 32-bit IPv4 address represented in dotted-decimal format, divided along 8-bit boundaries, and then converted to its decimal equivalent, separated by periods. The following examples show 128-bit IPv6 addresses in binary form:
Address 1: 0010000111011010000000001101001100000000000000000010111100111011
0000001010101010000000001111111111111110001010001001110001011010
Address2: 0010000111011010000000001101001100000000000000000010111100111011
0000001010101010000000001111111100000000000000001001110001011010
Address 3: 0010000111011010000000001101001100000000000000001001110001011010
0000001010101010000000001111111100000000000000001001110001011010
Address 4: 0010000111011010000000001101001100000000000000001001110001011010
0000001010101010000000001111111100000000000000000010111100111011
The following example shows these same addresses divided along 16-bit boundaries:
Address 1: 1:0010000111011010:0000000011010011:0000000000000000:0010111100111011:
0000001010101010:0000000011111111:1111111000101000:1001110001011010:
Address 2: 0010000111011010:0000000011010011:0000000000000000:0010111100111011:
0000001010101010:0000000011111111:0000000000000000:1001110001011010:
Address 3: 0010000111011010:0000000011010011:0000000000000000:1001110001011010:
0000001010101010:0000000011111111:0000000000000000:1001110001011010:
Address 4: 0010000111011010:0000000011010011:0000000000000000:1001110001011010:
0000001010101010:0000000011111111:0000000000000000:0010111100111011:
The following...
