Managing Serviceguard Nineteenth Edition, Reprinted June 2011

H IPv6 Network Support
This appendix describes some of the characteristics of IPv6 network addresses. Topics:
• IPv6 Address Types
• Network Configuration Restrictions
• Local Primary/Standby LAN Patterns
• IPv6 Relocatable Address and Duplicate Address Detection Feature (page 367)
IPv6 Address Types
Several IPv6 types of addressing schemes are specified in the RFC 2373 (IPv6 Addressing
Architecture). IPv6 addresses are 128-bit identifiers for interfaces and sets of interfaces. There are
various address formats for IPv6 defined by the RFC 2373. IPv6 addresses are broadly classified
as follows:
The following table explains the three types of IPv6 address types: unicast, anycast, and multicast.
Table 15 IPv6 Address Types
An address for a single interface. A packet sent to a unicast address is delivered to the interface
identified by that address.
Unicast
An address for a set of interfaces. In most cases these interfaces belong to different nodes. A
packet sent to an anycast address is delivered to one of these interfaces identified by the address.
Anycast
Since the standards for using anycast addresses is still evolving, they are not supported in HP-UX
as of now.
An address for a set of interfaces (typically belonging to different nodes). A packet sent to a
multicast address will be delivered to all interfaces identified by that address.
Multicast
Unlike IPv4, there are no broadcast addresses in IPv6 because their functions are superseded by
multicast.
Textual Representation of IPv6 Addresses
There are three conventional forms for representing IPv6 addresses as text strings:
• The first form is x:x:x:x:x:x:x:x, where x’s are the hexadecimal values of eight 16-bit
pieces of the 128-bit address. Example:
2001:fecd:ba23:cd1f:dcb1:1010:9234:4088.
• Some of the IPv6 addresses may contain a long strings of zero bits. In order to make it easy
for representing such addresses textually a special syntax is available. The use of “::” indicates
that there are multiple groups of 16-bits of zeros. The “::” can appear only once in an address
and it can be used to compress the leading, trailing, or contiguous sixteen-bit zeroes in an
address. Example:
fec0:1:0:0:0:0:0:1234 can be represented as fec0:1::1234.
• When dealing with a mixed environment of IPv4 and IPv6 nodes there is an alternative form
of IPv6 address that will be used. It is x:x:x:x:x:x:d.d.d.d, where 'x's are the hexadecimal
values of higher order 96 bits of IPv6 address and the 'd's are the decimal values of the 32-bit
lower order bits. Typically IPv4 Mapped IPv6 addresses and IPv4 Compatible IPv6 addresses
will be represented in this notation. These addresses will be discussed in later sections.
Examples:
0:0:0:0:0:0:10.1.2.3
and
::10.11.3.123
364 IPv6 Network Support