Igmp Querier; Introduction - Raisecom ISCOM2600G-HI (A) Series Configuration Manual

Raisecom
ISCOM2600G-HI (A) Series Configuration Guide
Checking results
Disconnect any link in the ring, and check whether the multicast flow can be received
normally.

8.4 IGMP Querier

8.4.1 Introduction

MVR Querier is an MVR protocol proxy mechanism. It runs on Layer 2 devices to assist in
managing and controlling multicast groups. MVR Querier will terminate IGMP packets. It can
agent host functions upstream and also proxy multicast router functions downstream. The
Layer 2 network device enabled with MVR Querier has two roles:


The proxy mechanism can control and access user information effectively, and reduce the
network side protocol packet and network load.
IGMP Querier establishes a multicast packet forwarding list by intercepting IGMP packets
between the user and multicast routers.
IGMP Querier is used in cooperation with IGMP Snooping/MVR.
The following concepts are related to IGMP Querier.

IGMP packet suppression means that the switch filters identical Report packets. When
receiving multiple Report packets from a multicast group member in a query interval, the
switch sends the first Report packet to the multicast router only while it suppresses other
identical Report packets, to reduce packet quantity on the network.
When IGMP Snooping, IGMP MVR, or multicast VLAN copy is enabled, IGMP packet
suppression can be enabled or disabled respectively.

If a switch is enabled with this function, it can actively send IGMP Query packets to query
information about multicast members on the interface. If it is disabled with this function, it
only forwards IGMP Query packets from routers.
When IGMP Snooping, IGMP MVR, or multicast VLAN copy is enabled, IGMP
Querier can be enabled or disabled respectively.
At the user side, it is a query builder and undertakes the role of the server, sending Query
packets and periodically checking user information, and processing the Report and Leave
packets from users.
At the network routing side, it is a host and undertakes the role of the client, responding
the multicast router Query packet and sending Report and Leave packets. It sends the
user information to the network as required.
IGMP packet suppression
IGMP Querier
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