IP Multicast Overview
For multicast addressing, there are generally two types of addresses as follows: Well known addresses designated by IANA
Packets using the following Reserved Link Local Addresses (also called the Local Network Control Block [188.8.131.52 - 184.108.40.206]) are sent throughout the local subnet only and are transmitted with TTL=1.
The addresses listed below are just a few of the many addresses in the Link Local Address space.
—Sent to all systems on a subnet.
—Sent to all routers on a subnet.
—Sent to all OSPF routers.
—Sent to all OSPF DRs.
—Sent to all RIPv2 routers.
—Sent to all IGRP routers.
—Sent to all PIMv2 routers.
—Sent to all IGMPv3 devices.
Packets using the following Internetwork Control Block (220.127.116.11 - 18.104.22.168) addresses are
also sent throughout the network.
The addresses listed below are just a few of the many addresses in the Internetwork Control Block.
— Cisco-RP-Discovery (Auto-RP)
Administratively scoped addresses (22.214.171.124 - 126.96.36.199). For more information, see RFC 2365.
For more information about multicast addresses, see http://www.iana.org/assignments/multicast-addresses.
Administratively-scoped addresses should be constrained to a local group or organization. They are used in a private address space and are not used for global Internet traffic. “Scoping” can be implemented to restrict groups with a given address or range from being forwarded to certain areas of the network.
Organization-local and site-local scopes are defined scopes that fall into the administratively scoped address range.
Organization-local scope (188.8.131.52 - 184.108.40.206)—Regional or global applications that are
used within a private enterprise network.
Site-local scope (220.127.116.11 - 18.104.22.168)—Local applications that are isolated within a site/region and blocked on defined boundaries.
Scoping group addresses to applications allows for easy identification and control of each application.
The addressing used in this chapter reflects the organization-local scope and site-local scope ranges found in the administratively scoped address range.
Cisco AVVID Network Infrastructure IP Multicast Design