UMN:CLI User ManualV8102500TCN Flooding SuppressionWhen TCN is received, the switch where an IGMP snooping is running will flood multicasttraffic to all ports until receiving two general queries, or during two general query intervalsby default. You can also configure the switch to stop multicast flooding according to aspecified query count or query interval.To specify a query count to stop multicast flooding, use the following command.Command Mode Descriptionip igmp snooping tcn flood que-ry count <1-10> GlobalSpecifies a query count to stop multicast flooding.1-10: query count value (default: 2)no ip igmp snooping tcn floodquery countDeletes a specified query count to stop multicast flood-ing.To specify a query interval to stop multicast flooding, use the following command.Command Mode Descriptionip igmp snooping tcn flood que-ry interval <1-1800> GlobalSpecifies a query interval to stop multicast flooding inthe unit of second. An actual stop-flooding interval iscalculated by (query count) x (query interval).1-1800: query interval value (default: 125)no ip igmp snooping tcn floodquery intervalDeletes a specified query interval to stop multicastflooding.TCN Flooding Query SolicitationTypically, if a network topology change occurs, the spanning tree root switch issues aquery solicitation which is actually a global leave message with the group address 0.0.0.0.When a multicast router receives this solicitation, it immediately sends out IGMP generalqueries to hosts, allowing the fast convergence. You can direct the switch where an IGMPsnooping is running to send a query solicitation when TCN is received.To enable the switch to send a query solicitation when TCN is received, use the followingcommand.Command Mode Descriptionip igmp snooping tcn querysolicit [address A.B.C.D] GlobalEnables the switch to send a query solicitation whenTCN is received.address: source IP address for query solicitationTo disable the switch to send a query solicitation when TCN is received, use the followingcommand.Command Mode Descriptionno ip igmp snooping tcn querysolicit [address] Global Disables the switch to send a query solicitation whenTCN is received.
