User manual

C HAPTER 4 | Configuring the Switch
IGMP Snooping
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passing between multicast clients and servers, and dynamically configure
the switch ports which need to forward multicast traffic.
Multicast routers use information from IGMP snooping and query reports,
along with a multicast routing protocol such as DVMRP or PIM, to support
IP multicasting across the Internet.
PATH
Advanced Configuration, IPMC, IGMP Snooping, Basic Configuration
PARAMETERS
These parameters are displayed:
Global Configuration
◆ Snooping Enabled - When enabled, the switch will monitor network
traffic to determine which hosts want to receive multicast traffic.
(Default: Enabled)
This switch can passively snoop on IGMP Query and Report packets
transferred between IP multicast routers/switches and IP multicast host
groups to identify the IP multicast group members. It simply monitors
the IGMP packets passing through it, picks out the group registration
information, and configures the multicast filters accordingly.
◆ Unregistered IPMC Flooding Enabled - Floods unregistered
multicast traffic into the attached VLAN. (Default: Disabled)
Once the table used to store multicast entries for IGMP snooping is
filled, no new entries are learned. If no router port is configured in the
attached VLAN, and Unregistered IPMC Flooding is disabled, any
subsequent multicast traffic not found in the table is dropped,
otherwise it is flooded throughout the VLAN.
◆ IGMP SSM Range - The Source-Specific Multicast Range allows SSM-
aware hosts and routers to run the SSM service model for groups in the
specified address range. (Default: 232.0.0.0/8)
IPv4 addresses in the 232.0.0.0 to 232.255.255.255 range are
currently designated by RFC 4607 as SSM destination addresses and
are reserved for use by source-specific applications and protocols.
SSM-aware hosts and routers running the SSM service model can pass
traffic for any group within the specified address range.
When using IGMPv3 snooping (see the Compatibility parameter under
"Configuring VLAN Settings for IGMP Snooping and Query"), service
requests from IGMP Version 1, 2 or 3 hosts are all forwarded to the
upstream router as IGMPv3 reports. The primary enhancement
provided by IGMPv3 snooping is in keeping track of information about
the specific multicast sources which downstream IGMPv3 hosts have
requested or refused. The switch maintains information about both
multicast groups and channels, where a group indicates a multicast
flow for which the hosts have not requested a specific source (the only
option for IGMPv1 and v2 hosts unless statically configured on the
switch as described under "Configuring IGMP Filtering"), and a channel
indicates a flow for which the hosts have requested service from a