Igmp Proxy Overview; Figure 7: Upstream And Downstream Interfaces - Juniper JUNOSE 11.0.X MULTICAST ROUTING Configuration Manual

JUNOSe 11.0.x Multicast Routing Configuration Guide

IGMP Proxy Overview

IGMP proxy enables the router to issue IGMP host messages on behalf of hosts that
the router discovered through standard IGMP interfaces. The router acts as a proxy
for its hosts. E Series routers support IGMP proxy versions 2 and 3.
Figure 7 on page 72 shows a router in an IGMP proxy configuration. You enable
IGMP proxy on one interface, which connects to a router closer to the root of the
tree. This interface is the upstream interface. The router on the upstream interface
is running IGMP.
You enable IGMP on the interfaces that connect the router to its hosts that are farther
away from the root of the tree. These interfaces are known as downstream interfaces.

Figure 7: Upstream and Downstream Interfaces

As described in "IGMP Overview" on page 44, earlier in this chapter, hosts interact
with the router through the exchange of IGMP messages. Similarly, when you
configure IGMP proxy, the router interacts with the router on its upstream interface
72

IGMP Proxy Overview

port Port number on the I/O module
limit Maximum number of IGMP groups that the port can accept. A value
of –1 indicates that no limit has been specified.
count Actual number of IGMP groups that the port has accepted
Example
host1:boston#show multicast group limit
Port limit count
--------- ----- -----
2/0 5 0
2/1 -1 1
See show multicast group limit.