Multicast Filtering
RocketLinx ES7528 Industrial Managed PoE Rack Mount User Guide
: 2000509 Rev. A
- 95
Multicast Filtering
Multicast Filtering
For multicast filtering, the RocketLinx ES7528 uses IGMP (Internet Group Management Protocol) Snooping technology.
IGMP is an internet protocol that provides a way for internet device to report its multicast group membership to adjacent
routers. Multicasting allows one computer on the internet to send data to a multitude of other computers that have identified
themselves as being interested in receiving the originating computers data.
Multicasting is useful for such applications as updating the address books of mobile computer users in the field, sending out
newsletters to a distribution list, and broadcasting streaming media to an audience that has tuned into the event by setting up
multicast group membership.
In effect, IGMP Snooping manages multicast traffic by making use of switches, routers, and hosts that support IGMP. Enabling
IGMP Snooping allows the ports to detect IGMP queries, report packets, and manage multicast traffic through the switch.
IGMP has three fundamental types of messages, as shown in the following table.
You can enable
IGMP Snooping
and
IGMP Query
functions. This section illustrates the information of the IGMP Snooping
function, including different multicast groups’ VID and member ports, and IP multicast addresses that range from 224.0.0.0 to
239.255.255.255.
The following commands are included in this group:
•
IGMP Snooping
on Page 96
•
IGMP Query
on Page 97
•
Unknown Multicast
on Page 97
•
GMRP Configuration
on Page 98
•
CLI Commands for Multicast Filtering
on Page 99
Message
Description
Query
A message sent from the querier (an IGMP router or a switch) that asks for a
response from each host that belongs to the multicast group.
Report
A message sent by a host to the querier to indicate that the host wants to be or is
a member of a given group indicated in the report message.
Leave Group
A message sent by a host to the querier to indicate that the host has quit as a
member of a specific multicast group.
