IPv6 supports both single-destination (unicast) and multiple-destination
(multicast) addresses. Addresses comprise three different scopes.
IPv4 to
IPv6 Transition Addresses |
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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.
IPv6 Address
scope |
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Link-local: An IPv6 address used over one local link; assigned
during autoconfiguration.
Site-local: An IPv6 address used inside a local Intranet site
only; not renumbered by an ISP.
Global: An IPv6 address used throughout the Internet.
An IPv6 node always has a link-local address. It may have
a site-local address or one or more global addresses.
IPv4-Compatible
IPv6 Address |
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An administrator assigns an IPv4-compatible IPv6 address and
host name entry to the Name Service for an IPv4/IPv6 host where
no IPv6 router is available.The IPv4-compatible IPv6 address is
an IPv6 address in the format:
IPv4-Compatible Addresses help the migration process by enabling
IPv6 features without requiring IPv6 Routers.
IPv4-Mapped
Address |
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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.
