D-Link DES-3550 Command Line Interface Reference Manual page 167

config igmp_snooping querier
Purpose This command configures IGMP snooping querier.
Syntax config igmp_snooping querier [<vlan_name 32> | all] {query_interval <sec 1-65535> |
max_response_time <sec 1-25> | robustness_variable <value 1-255> |
last_member_query_interval <sec 1-25> | state [enable | disable]
Description Used to configure the time in seconds between general query transmissions, the maximum
time in seconds to wait for reports from members and the permitted packet loss that
guarantees IGMP snooping.
Parameters <vlan_name 32> − The name of the VLAN for which IGMP snooping querier is to be
configured.
query_interval <sec 1-65535> − Specifies the amount of time in seconds between general
query transmissions. The default setting is 125 seconds.
max_response_time <sec 1-25> − Specifies the maximum time in seconds to wait for
reports from members. The default setting is 10 seconds.
robustness_variable <value 1-255> − 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:
last_member_query_interval <sec 1-25> − 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.
state [enable | disable] − Allows the Switch to be specified as an IGMP Querier or Non-
querier.
Restrictions Only administrator-level users can issue this command.
DES-3550 Layer 2 Fast Ethernet Switch
•
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.
•
By default, the robustness variable is set to 2. You might want to increase this
value if you expect a subnet to be lossy. Although 1 is specified as a valid entry,
the roubustness variable should not be one or problems may arise.
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