Lenovo Flex System Fabric CN4093, Application Manual

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CN4093 Application Guide for N/OS 8.4
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.
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:
 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. Auto ‐ configured
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
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.
Routers must not forward any packets with link ‐ local source or destination
addresses to other links.
Multicast Address
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.
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
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:
FF00:::::::0
through
FF0F:::::::0