HP-UX IPv6 Porting Guide (February 2007)

IPv6 Addressing
Types of IPv6 addresses
Chapter 26
Types of IPv6 addresses
IPv6 supports both single-destination (unicast) and multiple-destination (multicast)
addresses. Addresses comprise three different scopes.
IPv6 Address scope
Link-local: An IPv6 address used over one local link; assigned during autoconfiguration.
Global: An IPv6 address used throughout the Internet.
An IPv6 node always has a link-local address. It may have one or more global addresses.
IPv4 to IPv6 Transition Addresses
To ease the transition from IPv4 to IPv6, the IPv6 Protocol Specifications define two global
IPv6 addresses containing unique IPv4 address in the low-order 32-bits of the IPv6 address.
IPv4-Mapped Address
An IPv4-mapped IPv6 address enables an IPv6 application on an IPv4/IPv6 host to
communicate with an IPv4-only node. IPv4-mapped IPv6 addresses are created internally by
the Name Service resolver when an IPv6 application requests the host name for a node with
an IPv4 address only.
The IPv6 module encodes the IPv4 address in the low-order 32 bits of the IPv6 address.
Figure 2-1 IPv4-Mapped Address