Datasheet

“main” (Installation and Administration) — 2004/6/25 — 13:29 — page 427 — #453
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21
Linux in the Network
2 or 3 as the first
digit
Aggregatable global unicast addresses. As is the
case with IPv4, an interface can be assigned to form
part of a certain subnetwork. Currently, there are
the following address spaces: 2001::/16 (produc-
tion quality address space) and 2002::/16 (6to4
address space).
fe80::/10 Link-local addresses. Addresses with this prefix
should not be routed and should therefore only be
reachable from within the same subnetwork.
fec0::/10 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 (e.g.,
10.x.x.x).
ff These are multicast addresses.
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 Inter-
net. 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.
I S/390, zSeries
Devices without MAC addresses on IBM S/390 and zSeries are IUCV
and CTC (point-to-point). J
427SUSE LINUX Enterprise Server