Blade ICE G8124 Manuale Utente
BLADEOS 6.5.2 Application Guide
232
Chapter 16: Internet Protocol Version 6
BMD00220, October 2010
IPv6 Address Types
IPv6 supports three types of addresses: unicast (one-to-one), multicast (one-to-many), and anycast
(one-to-nearest). Multicast addresses replace the use of broadcast addresses.
(one-to-nearest). Multicast addresses replace the use of broadcast addresses.
Unicast Address
Unicast is a communication between a single host and a single receiver. Packets sent to a unicast
address are delivered to the interface identified by that address. IPv6 defines the following types of
unicast address:
address are delivered to the interface identified by that address. IPv6 defines the following types of
unicast address:
Global Unicast address: An address that can be reached and identified globally. Global Unicast
addresses use the high-order bit range up to FF00, therefore all non-multicast and
non-link-local addresses are considered to be global unicast. A manually configured IPv6
address must be fully specified. Autoconfigured IPv6 addresses are comprised of a prefix
combined with the 64-bit EUI. RFC 4291 defines the IPv6 addressing architecture.
addresses use the high-order bit range up to FF00, therefore all non-multicast and
non-link-local addresses are considered to be global unicast. A manually configured IPv6
address must be fully specified. Autoconfigured IPv6 addresses are comprised of a prefix
combined with the 64-bit EUI. RFC 4291 defines the IPv6 addressing architecture.
The interface ID must be unique within the same subnet.
Link-local unicast address: An address used to communicate with a neighbor on the same link.
Link-local addresses use the format
Link-local addresses use the format
FE80::EUI
Link-local addresses are designed to be used for addressing on a single link for purposes such
as automatic address configuration, neighbor discovery, or when no routers are present.
as automatic address configuration, neighbor discovery, or when no routers are present.
Routers must not forward any packets with link-local source or destination addresses to other
links.
links.
Multicast
Multicast is communication between a single host and multiple receivers. Packets are sent to all
interfaces identified by that address. An interface may belong to any number of multicast groups.
interfaces identified by that address. An interface may belong to any number of multicast groups.
A multicast address (FF00 - FFFF) is an identifier for a group interface. The multicast address most
often encountered is a solicited-node multicast address using prefix
often encountered is a solicited-node multicast address using prefix
FF02::1:FF00:0000/104
with the low-order 24 bits of the unicast or anycast address.
The following well-known multicast addresses are pre-defined. The group IDs defined in this
section are defined for explicit scope values, as follows:
section are defined for explicit scope values, as follows:
FF00:::::::0
through
FF0F:::::::0