D-Link DGS-3120-48PC Reference Manual page 313

®
xStack
and 25 seconds.
robustness_variable - (Optional) 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:
<value 1-7> - Enter the robustness variable value here. This value must be between 1 and 7.
By default, the robustness variable is set to 2. You might want to increase this value if you
expect a subnet to be loosely.
•
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.
last_member_query_interval - (Optional) Specify the maximum amount of time between group-
specific query messages, including those sent in response to leave-group messages. You
might lower this interval to reduce the amount of time it takes a router to detect the loss of the
last member of a group. On receiving a leave message, the router will assume there are no
local members on the interface if there are no reports received after the response time (which
is last member query interval * robustness variable)
<sec 1-25> - Enter the last member query interval value here. This value must be between 1
and 25 seconds.
state - (Optional) If the state is enabled, it allows the Switch to be selected as an IGMP Querier
(sends IGMP query packets). It the state is disabled, then the Switch cannot play the role as a
querier. Note that if the Layer 3 router connected to the Switch provide only the IGMP proxy
function but does not provide the multicast routing function, then this state must be configured
as disabled. Otherwise, if the Layer 3 router is not selected as the querier, it will not send the
IGMP query packet. Since it will not send the multicast-routing protocol packet, the port will be
timed out as a router port.
enable - Enter enable to enable this state.
disable - Enter disable to disable this state.
version - (Optional) Specify the version of IGMP packet that will be sent by this port. If an IGMP
packet received by the interface has a version higher than the specified version, this packet
will be dropped.
<value 1-3> - Enter the version number here. This value must be between 1 and 3.
Restrictions
Only Administrator, Operator and Power-User level users can issue this command.
Example
To configure the IGMP snooping querier:
DGS-3120-24TC:admin# config igmp_snooping querier vlan_name default
query_interval 125 state enable
Command: config igmp_snooping querier vlan_name default query_interval 125
state enable
Success.
DGS-3120-24TC:admin#
DGS-3120 Series Managed Switch CLI Reference Guide
309