114 CHAPTER 6: MULTICAST PROTOCOL
multicast routing table, to determine the incoming interface at which the
packet arrives. If a source tree is used, the source address is the address of the
source host sending the multicast packet. If a shared tree is used, the source
address is the address of the root of the shared tree. When a multicast packet
arrives at the router, if RPF check succeeds, the packet will be forwarded
according to the multicast forwarding entry. Otherwise, the packet will be
dropped.
Applying Multicast IP multicast technology effectively solves the problem of packet forwarding from
single-point to multi-point. It implements high-efficient data transmission from
single-point to multi-point in IP networks and can save a large amount of network
bandwidth and reduce network loads. New value-added services that use
multicast can be delivered, including direct broadcasting, Web TV, distance
learning, distance medicine, net broadcasting station and real-time audio/video
conferencing.
Multimedia and streaming media applications
Communications of the training and corporate sites
Data repository and finance (stock) applications
Any “point-to-multi-point” data distribution
With the increase of multimedia services on IP networks, multicast has huge
market potential.
Configuring Common Multicast
A common multicast configuration covers both the multicast group management
protocol and the multicast routing protocol. The configuration includes enabling
multicast, configuring multicast forwarding boundary, and displaying multicast
routing table and multicast forwarding table.
Configuring Common
Multicast
Common multicast configuration includes:
Enabling Multicast
Configuring the Multicast Route Limit
Clearing MFC Forwarding Entries or Statistic Information
Clearing Route Entries From the Core Multicast Routing Table
Displaying and Debugging Common Multicast Configuration
Enabling Multicast
Enable multicast first before enabling the multicast routing protocol.
Perform the following configuration in system view.
By default, multicast routing is disabled.
Tabl e 116 Enabling Multicast
Operation Command
Enable multicast multicast routing-enable
Disable multicast undo multicast routing-enable