3Com Switch 7750 Configuration Guide Guide

380 CHAPTER 39: MULTICAST OVERVIEW
Note that:
■ The IP addresses of a permanent multicast group keep unchanged, while the
members of the group can be changed.
■ There can be any number of, or even zero, members in a permanent multicast
group.
■ Those IP multicast addresses not assigned to permanent multicast groups can
be used by temporary multicast groups.
Class D IP addresses range from 224.0.0.0 to 239.255.255.255. For details, see
Table 301.
As specified by IANA, the IP addresses ranging from 224.0.0.0 to 224.0.0.255 are
reserved for network protocols on local networks. The following table lists
commonly used reserved IP multicast addresses:
Tabl e 301 Range and description of Class D IP addresses
Class D address range Description
224.0.0.0 to 224.0.0.255
Reserved multicast addresses (IP addresses for
permanent multicast groups). The IP address
224.0.0.0 is reserved. Other IP addresses can
be used by routing protocols.
224.0.1.0 to 231.255.255.255
233.0.0.0 to 238.255.255.255
Available any-source multicast (ASM)
multicast addresses (IP addresses of temporary
groups). They are valid for the entire network.
232.0.0.0 to 232.255.255.255
Available source-specific multicast (SSM)
multicast group addresses.
239.0.0.0 to 239.255.255.255
Local management multicast addresses, which
are used in the local use only.
Tabl e 302 Reserved IP multicast addresses
Class D address range Description
224.0.0.1 Address of all hosts
224.0.0.2 Address of all multicast routers
224.0.0.3 Unassigned
224.0.0.4
Distance vector multicast routing protocol
(DVMRP) routers
224.0.0.5 Open shortest path first (OSPF) routers
224.0.0.6
Open shortest path first designated routers
(OSPF DR)
224.0.0.7 Shared tree routers
224.0.0.8 Shared tree hosts
224.0.0.9 RIP-2 routers
224.0.0.11 Mobile agents
224.0.0.12 DHCP server / relay agent
224.0.0.13
All protocol independent multicast (PIM)
routers
224.0.0.14
Resource reservation protocol (RSVP)
encapsulation