D-Link DGS-1520 User Manual - Page 288

DGS-1520 Series Gigabit Ethernet Smart Managed Switch Web UI Reference Guide The fields that can be configured are described below: Parameter Version State Query Interval Query Max Reponses Time Robustness Variable Last Member Query Interval Subscriber Source IP Check Description Select the IGMP version number here. The range is from 1 to 3. By default, this value is 3. Select the Default option to use the default version. Select to enable or disable the IGMP state on this interface here. Enter the query interval value here. The range is from 1 to 31744 seconds. The IGMP querier sends IGMP query messages at the interval specified here to discover the receivers attached to the interface interested in joining the multicast group. Hosts respond to the query with IGMP report messages to indicate the multicast group they are interested in joining. Select the Default option to use the default value. Enter the maximum query response time value here. The range is from 1 to 25 seconds. This configures the period of time, which the group member can respond to an IGMP query message before the router removes the membership. The group membership lifetime is equal to the query interval times the robustness plus the maximum response time. Select the Default option to use the default value. Enter the robustness variable value here. The range is from 1 to 7. The robustness variable provides fine-tuning to allow for expected packet loss on an interface. Select the Default option to use the default value. Enter the Last Member Query Interval value here. The range is from 1 to 25 seconds. When the router receives a leave message from a receiver to leave a group or a channel, the router will send the Group Specific Query or Group-Source Specific Query message to the receiver interface. The IGMP Last Member Query Interval will be advertised in the query message and conveyed to the receiver. This configures the period that the router will send the next group-specific query or group-source specific query message if there is no report from receiver for the specific group or specific channel. The router will retry for the last member query count. If no report messages are received after the retry count, the interface will remove the membership from the specific group or specific channel. Select the Default option to use the default value. Select to enable or disable the subscriber source IP check feature here. By default, the IGMP report or leave messages received by the interface will be checked to determine whether its source IP is in the same network as the interface. If they are not in the same network, the message information won't be learned by the IGMP protocol. Click the Back button to return to the previous window. Click the Apply button to accept the changes made. 278