Technical data

BLADE OS 5.1 Application Guide
BMD00136, November 2009 Chapter 12: IPv6 Host Management
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Multicast
Multicast is communication between a single host and multiple receivers. Packets are sent to all
interfaces identified by that address. An interface may belong to any number of multicast groups.
A multicast address (FF00 - FFFF) is an identifier for a group interface. The multicast address most
often encountered is a solicited-node multicast address using prefix FF02::1:FF00:0000/104
with the low-order 24 bits of the unicast or anycast address.
The following well-known multicast addresses are pre-defined. The group IDs defined in this
section are defined for explicit scope values, as follows:
FF00:::::::0 through FF0F:::::::0
Anycast
Packets sent to an anycast address or list of addresses are delivered to the nearest interface identified
by that address. Anycast is a communication between a single sender and a list of addresses.
Anycast addresses are allocated from the unicast address space, using any of the defined unicast
address formats. Thus, anycast addresses are syntactically indistinguishable from unicast addresses.
When a unicast address is assigned to more than one interface, thus turning it into an anycast
address, the nodes to which the address is assigned must be explicitly configured to know that it is
an anycast address.
IPv6 Address Autoconfiguration
IPv6 supports the following types of address autoconfiguration:
 Stateful address configuration
Address configuration is based on the use of a stateful address configuration protocol, such as
DHCPv6, to obtain addresses and other configuration options.
 Stateless address configuration
Address configuration is based on the receipt of Router Advertisement messages that contain
one or more Prefix Information options.
The switch supports stateless address configuration.
Stateless address configuration allows hosts on a link to configure themselves with link-local
addresses and with addresses derived from prefixes advertised by local routers. Even if no router is
present, hosts on the same link can configure themselves with link-local addresses and
communicate without manual configuration.