Managing HP Serviceguard for Linux, Eighth Edition, March 2008

IPv6 Network Support
IPv6 Address Types
Appendix E376
Unicast Addresses
IPv6 unicast addresses are classified into different types. They are:
global aggregatable unicast address, site-local address and link-local
address. Typically a unicast address is logically divided as follows:
Interface identifiers in a IPv6 unicast address are used to identify the
interfaces on a link. Interface identifiers are required to be unique on
that link. The link is generally identified by the subnet prefix.
A unicast address is called an unspecified address if all the bits in the
address are zero. Textually it is represented as “::”.
The unicast address ::1 or 0:0:0:0:0:0:0:1 is called the loopback
address. It is used by a node to send packets to itself.
IPv4 and IPv6 Compatibility
There are a number of techniques for using IPv4 addresses within the
framework of IPv6 addressing.
IPv4 Compatible IPv6 Addresses
The IPv6 transition mechanisms use a technique for tunneling IPv6
packets over the existing IPv4 infrastructure. IPv6 nodes that support
such mechanisms use a special kind of IPv6 addresses that carry IPv4
addresses in their lower order 32-bits. These addresses are called IPv4
Compatible IPv6 addresses. They are represented as follows:
Example:
::192.168.0.1
Table E-2
n bits 128-n bits
Subnet prefix Interface ID
Table E-3
80 bits 16 bits 32 bits
zeros 0000 IPv4 address