D-Link DES-1210/ME Series Manual page 53

4 Configuration
By default, IGMP is disabled. If enabled, the IGMP Global Settings will need to be entered:
Host Timeout (130-153025 sec): This is the interval after which a learned host port entry will be purged. For
each host port learned, a 'Port Purge Timer' runs for 'Host Port Purge Interval'. This timer will be restarted
whenever a report message from host is received over that port. If no report messages are received for 'Host
Port Purge Interval' time, the learned host entry will be purged from the multicast group. The default value is
260 seconds.
Max Learned Entry Value (1-512): The Max Learned Entry Value allows adjustment for the value. Default
value is 256.
Router Timeout (60-600 sec): This is the interval after which a learned router port entry will be purged. For
each router port learned, a 'Router Port Purge Timer' runs for 'Router Port Purge Interval'. This timer will be
restarted whenever a Query control message is received over that port. If there were no Query control
messages received for 'Router Port Purge Interval' time, the learned router port entry will be purged. Default
is 260 seconds.
Click IGSEdit button to enter the IGMP Parameters Settings page, and the parameters to be configured in
the following page.
Figure 4.70 – Configuration > IGMP Snooping > IGMP Snooping – IGSEdit page
Robustness Variable (2-255): The Robustness Variable allows adjustment for the expected packet loss on
a subnet. If a subnet is expected to be lossy, the Robustness Variable may need to be increased. The
Robustness Variable cannot be set to zero, and it SHOULD NOT be. Default is 2 seconds.
Last Member Query Interval (1-25 sec): The Last Member Query Interval is the Max Response Time
inserted into Group-Specific Queries sent in response to Leave Group messages, and is also the amount of
time between Group-Specific Query messages. This value may be adjusted to modify the "leave latency" of
the network. A reduced value results in reduced time to detect the loss of the last member of a group. Default
is 1 second.
Query Interval (60-600 sec): The Query Interval is the interval between General Queries sent. By adjusting
the Query Interval, the number of IGMP messages can be increased or decreased; larger values will cause
IGMP Queries to be sent less often. Default value is 125 seconds.
Max Response Time (10-25 sec): The Max Response Time specifies the maximum allowed time before
sending a responding report message. Adjusting this setting effects the "leave latency", or the time between
DES-1210/ME Series Metro Ethernet Managed Switch User Manual
Figure 4.69 – Configuration > IGMP Snooping > IGMP Snooping
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