Ruijie RG-S2900G-E Series - Page 416

Configuration Guide IGMP Snooping Configuration
Aging timer
for the
dynamic
router port
Enable a timer for
each dynamic router
port. The timeout time
is the aging time of
the dynamic router
port.
Receive the IGMP
general query packet
or the IP PIM Hello
packet.
Remove the port
from the router port
list.
Aging timer
for the
dynamic
member
port
Enable a timer for
each dynamic
member port. The
timeout time is the
aging time of the
dynamic member
port.
Receive the IGMP
query packet.
Remove the port
from the IGMP
Snooping multicast
group forwarding list.
Working Principle
General Query and Specific-Group Query
IGMP querier sends the general query packets to all hosts and routers(with the address:
224.0.0.1) in the local network segment periodically to query for the IP multicast group member
in the network segment. Upon receiving the IGMP general query packets, the switch forwards
those query packets to all ports in this VLAN, and processes the packet-receiving port as
follows:
 If this port has already been in the router port list, reset the aging timer.
 If this port has not been in the router port list, add the port to the list and enable the aging
timer.
 After receiving the IGMP general query packets, the multicast device enable the aging
timer for all member ports. Set the aging time as the maximum respond time of the IGMP
query packets. When the aging time is 0, no member port receives the multicast flow and
the port will be removed from the IGMP Snooping forwarding list.
After receiving the IGMP specific-group query packets, the multicast device enable the aging
timer for all member ports in the specific group. Set the aging time as the maximum respond
time of the IGMP query packets. When the aging time is 0, no member port receives the
multicast flow and the port will be removed from the IGMP Snooping forwardin.
For the IGMP specific-group source query packets, it is no need to update the aging timer.
Membership Report
In the following circumstances, the host sends the IGMP membership report to the IGMP
querier: