608
Group1 and Group2, three of four hosts running multicast applications are connected to
port 2, 6, 10 plays program1, while the host is connected to port 12 plays program 2.
IGMP Snooping listening result:
The multicast table built by IGMP Snooping in VLAN 100 indicates ports 1, 2, 6, 10 in
Group1 and ports 1, 12 in Group2.
All the four hosts can receive the program of their choice: ports 2, 6, 10 will not receive
the traffic of program 2 and port 12 will not receive the traffic of program 1.
Scenario 2. IGMP Query
Multicast Router
Mrouter Port
IGMP Snooping
Group 1 Group 1 Group 1 Group 2
Switch2
Group 1 Group 2
IGMP Snooping
Query
Switch1
Fig 15-1 The switches as IGMP Queries
The configuration of SwitchB is the same as the switch in scenario 1, SwitchA takes the
place of Multicast Router in scenario 1. Let’s assume VLAN 60 is configured in SwitchA,
including ports 1, 2, 6, 10 and 12. Port 1 connects to the multicast server, and port 2
connects to SwitchB. In order to send Query at regular interval, IGMP query must
enabled in Global mode and in VLAN60.
SwitchA