Operation Manual – IPv6
H3C S5500-EI Series Ethernet Switches
Chapter 1 IPv6 Basics Configuration
1-5
Note:
There are no broadcast addresses in IPv6. Their function is superseded by multicast
addresses.
The type of an IPv6 address is designated by the first several bits called format prefix.
Table 1-1
lists the mappings between address types and format prefixes.
Table 1-1
Mapping between address types and format prefixes
Type
Format prefix (binary)
IPv6 prefix ID
Unassigned
address
00...0 (128 bits)
::/128
Loopback
address
00...1 (128 bits)
::1/128
Link-local
address
1111111010 FE80::/10
Site-local
address
1111111011 FEC0::/10
Unicast
address
Global unicast
address
other forms
—
Multicast address
11111111 FF00::/8
Anycast address
Anycast addresses are taken from unicast address
space and are not syntactically distinguishable from
unicast addresses.
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.
z
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.
z
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.
z
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).
z
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