Amer Networks E5Web GUI - Manual (Page 332)

4.7.3. IGMP Configuration
IGMP signalling between hosts and routers can be divided into two categories:
• IGMP Reports
Reports are sent from hosts towards the router when a host wants to subscribe to new
multicast groups or change current multicast subscriptions.
• IGMP Queries
Queries are IGMP messages sent from the router towards the hosts in order to make sure that
it will not close any stream that some host still wants to receive.
Normally, both types of rule have to be specified for IGMP to function but there are two
exceptions:
1. If the multicast source is located on a network directly connected to the router, no query
rule is needed.
2. If a neighboring router is statically configured to deliver a multicast stream to the Clavister
Security Gateway, an IGMP query would also not have to be specified.
cOS Core supports two IGMP modes of operation:
• Snoop Mode
• Proxy Mode
The operation of these two modes are shown in the following illustrations:
Figure 4.22. Multicast Snoop Mode
Chapter 4: Routing
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