LevelOne GEL-2670 User Manual page 152

| Configuring the Switch
C 4
HAPTER
IGMP Snooping
P
ARAMETERS
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.
Leave Proxy Enabled - Suppresses leave messages unless received
◆
from the last member port in the group. (Default: Disabled)
IGMP leave proxy suppresses all unnecessary IGMP leave messages so
that a non-querier switch forwards an IGMP leave packet only when the
last dynamic member port leaves a multicast group.
The leave-proxy feature does not function when a switch is set as the
querier. When the switch is a non-querier, the receiving port is not the
last dynamic member port in the group, the receiving port is not a
router port, and no IGMPv1 member port exists in the group, the switch
will generate and send a group-specific (GS) query to the member port
which received the leave message, and then start the last member
query timer for that port.
When the conditions in the preceding item all apply, except that the
receiving port is a router port, then the switch will not send a GS-query,
but will immediately start the last member query timer for that port.
Leave proxy is also included in the general proxy function described
below. Therefore if Leave Proxy Enabled is not selected, but Proxy
Enabled is selected, leave proxy will still be performed.
Proxy Enabled – Enables IGMP Snooping with Proxy Reporting.
◆
(Default: Disabled)
When proxy reporting is enabled with this command, the switch
performs "IGMP Snooping with Proxy Reporting" (as defined in DSL
Forum TR-101, April 2006), including report suppression, last leave,
and query suppression.
Report suppression intercepts, absorbs and summarizes IGMP reports
coming from downstream hosts. Last leave sends out a proxy query
when the last member leaves a multicast group, and query suppression
means that neither specific queries nor general queries are forwarded
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