HP A7500 Series Configuration Manual page 110

CAUTION:
A double colon may appear once or not at all in an IPv6 address. This limit allows the device to determine
how many zeros the double colon represents, and correctly convert it to zeros to restore a 128-bit IPv6
address.
An IPv6 address consists of an address prefix and an interface ID, both of which are equivalent to the
network ID and the host ID of an IPv4 address, respectively.
An IPv6 address prefix is written in IPv6-address/prefix-length notation where the IPv6-address is
represented in any of the formats previously mentioned and the prefix-length is a decimal number
indicating how many leftmost bits of the IPv6 address comprises the address prefix.
IPv6 address types
IPv6 addresses fall into three types: unicast address, multicast address, and anycast address.
Unicast address: An identifier for a single interface, similar to an IPv4 unicast address. A packet
•
sent to a unicast address is delivered to the interface identified by that address.
Multicast address: An identifier for a set of interfaces (typically belonging to different nodes),
•
similar to an IPv4 multicast address. A packet sent to a multicast address is delivered to all
interfaces identified by that address.
• Anycast address: An identifier for a set of interfaces (typically belonging to different nodes). A
packet sent to an anycast address is delivered to the nearest one of the interfaces identified by that
address. The nearest interface is chosen according to the routing protocols' measure of distance.
NOTE:
There are no broadcast addresses in IPv6. Their function is replaced by multicast addresses.
The type of an IPv6 address is designated by the first several bits, the format prefix.
mappings between address types and format prefixes.
Table 7 Mappings between address types and format prefixes
Type
Unicast
address
Multicast address
Anycast address
Unicast addresses
Unicast addresses comprise global unicast addresses, link-local unicast addresses, site-local unicast
addresses, the loopback address, and the unspecified address.
Global unicast addresses, equivalent to public IPv4 addresses, are provided for network service
•
providers. This type of address allows efficient prefix aggregation to restrict the number of global
routing entries.
Unspecified address
Loopback address
Link-local address
Site-local address
Global unicast address
Format prefix (binary)
00...0 (128 bits)
00...1 (128 bits)
1111111010
1111111011
Other forms
11111111
Anycast addresses use the unicast address space and have the
identical structure of unicast addresses.
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Table 7
IPv6 prefix ID
::/128
::1/128
FE80::/10
FEC0::/10
—
FF00::/8
lists the