Reserved Ip Multicast Addresses; Ip Multicast Routing - Alcatel-Lucent OmniSwitch 6850-48 Network Configuration Manual

Configuring IP Multicast Switching

Reserved IP Multicast Addresses

The Internet Assigned Numbers Authority (IANA) created the range for multicast addresses, which is
224.0.0.0 to 239.255.255.255. However, as the table below shows, certain addresses are reserved and
cannot be used.
Address or Address Range
224.0.0.0 through 224.0.0.255
224.0.1.0 through 224.0.1.255
224.0.2.0 through 224.0.255.0
224.1.0.0 through 224.1.255.255
224.2.0.0 through 224.2.255.255
224.252.0.0 through 224.255.255.255
225.0.0.0 through 231.255.255.255
232.0.0.0 through 232.255.255.255
233.0.0.0 through 233.255.255.255
234.0.0.0 through 238.255.255.255
239.0.0.0 through 239.255.255.255

IP Multicast Routing

IP multicast routing can be used for IP Multicast Switching and Routing (IPMSR). IP multicast routing is
a way of controlling multicast traffic across networks. The IP multicast router discovers which networks
want to receive multicast traffic by sending out Internet Group Management Protocol (IGMP) queries and
receiving IGMP reports from attached networks. The IGMP reports signal that users want to join a multi-
cast group.
If there is more than one IP multicast router in the network, the router with the lowest IP address is elected
as the querier router, which is responsible for querying the subnetwork for group members.
The IP multicast routing package provides the following two separate protocols:
•
Protocol Independent Multicast — Sparse Mode (PIM-SM) and Dense Mode (PIM-DM), which is
described in "PIM" on page
•
Distance Vector Multicast Routing Protocol (DVMRP), which is described in
page 42-8.
The multicast routing protocols build and maintain a multicast routing database. The multicast routing
protocols forward multicast traffic to networks that have requested group membership to a specific multi-
cast group. IPMS uses decisions made by the routing protocols and forwards multicast traffic to ports that
request group membership. See the OmniSwitch AOS Release 6 Advanced Routing Configuration Guide
for more information on IP multicast routing protocols.
OmniSwitch AOS Release 6 Network Configuration Guide
Description
Routing protocols (e.g., OSPF, RIP2)
Internetwork Control Block (e.g., RSVP, DHCP, commer-
cial servers)
AD-HOC Block (e.g., commercial servers)
ST Multicast Groups
SDP/SAP Block
DIS Transient Groups
Reserved
Source Specific Multicast
GLOP Block
Reserved
Administratively Scoped
42-8.
September 2009
IPMS Overview
"DVMRP" on
page 42-7