Novell LINUX ENTERPRISE DESKTOP 10 SP2 - DEPLOYMENT GUIDE 08-05-2008 Deployment Manual page 622

Prefix (hex)
fe80::/10
fec0::/10
ff
A unicast address consists of three basic components:
Public Topology
The first part (which also contains one of the prefixes mentioned above) is used to
route packets through the public Internet. It includes information about the company
or institution that provides the Internet access.
Site Topology
The second part contains routing information about the subnetwork to which to
deliver the packet.
Interface ID
The third part identifies the interface to which to deliver the packet. This also allows
for the MAC to form part of the address. Given that the MAC is a globally unique,
fixed identifier coded into the device by the hardware maker, the configuration
procedure is substantially simplified. In fact, the first 64 address bits are consoli-
dated to form the EUI-64 token, with the last 48 bits taken from the MAC, and
the remaining 24 bits containing special information about the token type. This also
makes it possible to assign an EUI-64 token to interfaces that do not have a MAC,
such as those based on PPP or ISDN.
On top of this basic structure, IPv6 distinguishes between five different types of unicast
addresses:
:: (unspecified)
This address is used by the host as its source address when the interface is initialized
for the first time—when the address cannot yet be determined by other means.
606 Deployment Guide
Definition
Link-local addresses. Addresses with this prefix should not be
routed and should therefore only be reachable from within the
same subnetwork.
Site-local addresses. These may be routed, but only within the
network of the organization to which they belong. In effect, they
are the IPv6 equivalent of the current private network address
space, such as 10.x.x.x.
These are multicast addresses.