D-Link DES-6500 - Switch User Manual page 178

part of a report packet. If the filter mode is exclude, traffic is being denied from at least one specific source, yet other hosts may be
accepting traffic from the multicast group. If the group timer expires for the multicast group, the filter mode is changed to include
and other hosts can receive traffic from the source. If no group report packet is received and the filter mode is include, the Switch
presumes that traffic from the source is no longer wanted on the attached network and the source record list is then deleted after all
source timers expire. If there is no source list record in the multicast group, the multicast group will be deleted from the Switch.
Timers are also used for IGMP version 1 and 2 members, which are a part of a multicast group when the Switch is running
IGMPv3. This timer is based on a host within the multicast group that is running IGMPv1 or v2. Receiving a group report from an
IGMPv1 or v2 host within the multicast group will refresh the timer and keep the v1 and/or v2 membership alive in v3.
xStack DES-6500 Modular Layer 3 Chassis Ethernet Switch User Manual
NOTE: The length of time for all timers utilized in IGMPv3 can be determined using
IGMP configurations to perform the following calculation:
(Group Membership Interval x Robustness Variable) + One Query Response Interval
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