D-Link DES-3326 User Manual - Multicast Addressing
DES-3326 Layer 3 Fast Ethernet Switch User’s Guide
Switch Management and Operating Concepts
97
single network device to another, single network device. Broadcast
packets are sent to all devices on the subnetwork. Multicast
defines a group of network devices or computers that will receive
the multicast packets. The members of this group are not
necessarily on the same subnetwork. Multicast addresses are used
to send multicast packets to the group members.
Multicast Addressing
Class D IP addresses are assigned to a group of network devices
that comprise a multicast group. The four most significant four
bits of a Class D address are set to “1110”. The following 28 bits is
referred to as the ‘multicast group ID’. Some of the range of Class
D addresses are registered with the Internet Assigned Numbers
Authority (IANA) for special purposes. For example, the block of
multicast addresses ranging from 224.0.0.1 to 224.0.0.225 is
reserved for use by routing protocols and some other low-level
topology discovery and maintenance protocols.
Figure 5-16. Class D Multicast Address
Some of the reserved IP multicast addresses are as follows:
Address Meaning
224.0.0.0
Base Address (reserved)
224.0.0.1
All Systems on this subnet
224.0.0.2
All Routers on this subnet