Configuration
D-Link Web Smart Switch User Manual
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Figure 4.45 – L2 Functions > Multicast > IGMP Snooping
By default, IGMP is
Disabled
. If enabled, the IGMP Global Settings will need to be entered:
Host Timeout (130-153025):
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.
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. The default value is
2
.
Query Interval (60-600):
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.
Router Timeout (60-600):
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 are no Query control
messages received for 'Router Port Purge Interval' time, the learned router port entry will be purged. Default
is
125
seconds.
Last Member Query Interval (1-25):
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.
Max Response Time (10-25):
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 the
moment the last host leaves a group and when the multicast server is notified that there are no more
members. It also allows adjustments for controlling the frequency of IGMP traffic on a subnet. Default is
10
seconds.
To enable IGMP snooping for a given VLAN, select Enabled and click the
Apply
button. Then, click the
VLAN ID hyperlink to see the following window. Select the ports to be assigned as router ports for IGMP
snooping for the VLAN, and click
Apply
for changes to take effect. A router port configured manually is a
Static Router Port
, and a
Dynamic Router Port
is dynamically configured by the Switch when query control
message is received.
