31: Configuring multicasting using PIM and IGMP interfaces
_______________________________________________________________________________________________________
_______________________________________________________________________________________________________
© Virtual Access 2018
GW2020 Series User Manual
Issue: 2.1
Page 320 of 423
31
Configuring multicasting using PIM and IGMP interfaces
31.1
Overview
IP multicast is a bandwidth-conserving technology that reduces traffic by simultaneously
delivering a single stream of information to potentially thousands of corporate recipients.
Applications that take advantage of multicast include video conferencing and corporate
communications.
IP multicast delivers application source traffic to multiple receivers without burdening the
source or the receivers while using a minimum of network bandwidth.
PIM (Protocol Independent Multicast) and IGMP (Internet Group Management Protocol)
are protocols used to create multicasting networks within a regular IP network.
A multicast group is an arbitrary group of receivers that expresses an interest in
receiving a particular data stream. The receivers (the designated multicast group) are
interested in receiving a data stream from the source. They indicate this by sending an
Internet Group Management Protocol (IGMP) host report to their closest router in the
network. The routers are then responsible for delivering the data from the source to the
receivers. The routers use Protocol Independent Multicast (PIM) between themselves to
dynamically create a multicast distribution tree. The data stream will then be delivered
only to the network segments that are in the path between the source and the receivers.
To summarize: PIM is used between routers while IGMP is used between a receiver and
its router only. As a result, PIM must be enabled on all the interfaces on the route from
the multicast source to the multicast client while IGMP must be enabled on the interface
to the multicast client only.
31.2
Configuration package used
Package
Sections
pimd
pimd
interface
31.3
Configuring PIM and IGMP using the web interface
To configure PIM through the web interface, in the top menu, select Network -> PIM.
The PIM page appears. To access the Global settings, click Add.
Figure 156: The global settings interface