D-Link DES-3026 Reference Manual - Page 148

DES-3000 Series Layer 2 Switch CLI Reference Manual config igmp_snooping querier Purpose Used to configure the time in seconds between general query transmissions, the maximum time in seconds to wait for reports from members and the permitted packet loss that guarantees IGMP snooping. Syntax config igmp_snooping querier [vlan_name | all] {query_interval | max_response_time | robustness_variable | last_member_query_interval | state [enable | disable]} Description This command configures IGMP snooping querier. Parameters vlan_name − The name of the VLAN for which IGMP snooping querier is to be configured. all - Selecting this parameter will configure IGMP for all VLANs on the Switch. query_interval − Specifies the amount of time in seconds between general query transmissions. The default setting is 125 seconds. max_response_time − Specifies the maximum time in seconds to wait for reports from members. The default setting is 10 seconds. robustness_variable − Provides fine-tuning to allow for expected packet loss on a subnet. The value of the robustness variable is used in calculating the following IGMP message intervals: • Group member interval-Amount of time that must pass before a multicast router decides there are no more members of a group on a network. This interval is calculated as follows: (robustness variable x query interval) + (1 x query response interval). • Other querier present interval-Amount of time that must pass before a multicast router decides that there is no longer another multicast router that is the querier. This interval is calculated as follows: (robustness variable x query interval) + (0.5 x query response interval). • Last member query count-Number of group-specific queries sent before the router assumes there are no local members of a group. The default number is the value of the robustness variable. • By default, the robustness variable is set to 2. Users may wish to increase this value if a subnet is expected to be lossy. last_member_query_interval − The maximum amount of time between group-specific query messages, including those sent in response to leave-group messages. The user may lower this interval to reduce the amount of time it takes a router to detect the loss of the last member of a group. state [enable | disable] − Allows the Switch to be specified as an IGMP Querier or Non-querier. Restrictions Only administrator-level users can issue this command. Example usage: To configure the igmp snooping: DES-3026:4#config igmp_snooping querier vlan_name default query_interval 125 state enable 144