H3C S3610-28P Operation Manual page 273

Operation Manual – IPv6
H3C S3610&S5510 Series Ethernet Switches
The type of an IPv6 address is designated by the first several bits called format prefix.
Table 1-1
Table 1-1 Mapping between address types and format prefixes
Unicast
address
Multicast address
Anycast address
III. Unicast address
There are several forms of unicast address assignment in IPv6, including aggregatable
global unicast address, link-local address, and site-local address.
The aggregatable global unicast address, equivalent to an IPv4 public address, is
provided for network service providers. The type of address allows efficient route
prefix aggregation to restrict the number of global routing entries.
The link-local address is used for communication between link-local nodes in
neighbor discovery and stateless autoconfiguration. Routers must not forward any
packets with link-local source or destination addresses to other links.
IPv6 unicast site-local addresses are similar to private IPv4 addresses. Routers
must not forward any packets with site-local source or destination addresses
outside of the site (equivalent to a private network).
Loopback address: The unicast address 0:0:0:0:0:0:0:1 (represented in the
shortest format as ::1) is called the loopback address and may never be assigned
to any physical interface. Like the loopback address in IPv4, it may be used by a
node to send an IPv6 packet to itself.
Unassigned address: The unicast address "::" is called the unassigned address
and may not be assigned to any node. Before acquiring a valid IPv6 address, a
node may fill this address in the source address field of an IPv6 packet, but may
not use it as a destination IPv6 address.
IV. Multicast address
IPv6 multicast addresses listed in
lists the mappings between address types and format prefixes.
Type
Unassigned
address
Loopback address
Link-local address
Site-local address
Global unicast
address
Chapter 1 IPv6 Basics Configuration
Format prefix (binary)
00...0 (128 bits)
00...1 (128 bits)
1111111010
1111111011
other forms
11111111
Anycast addresses are taken from unicast address
space and are not syntactically distinguishable from
unicast addresses.
Table 1-2 are reserved for special purpose.
1-5
IPv6 prefix ID
::/128
::1/128
FE80::/10
FEC0::/10
—
FF00::/8