Specifications

xStack DGS-3400 Series Layer 2 Gigabit Managed Switch CLI Manual
To configure IGMP snooping:
DGS-3400:4# config igmp_snooping vlan default host_timeout 250 state enable
Command: config igmp_snooping vlan default host_timeout 250 state enable
Success.
DGS-3400:4#
NOTE: The Fast Leave function in the config igmp_snooping command can only be implemented if
IGMP is disabled for all IP interfaces on the Switch. Configuring this function when IGMP is enabled
will produce the error message “Cannot set Fast leave when IGMP is running” and consequently will
not be implemented.
config igmp_snooping querier
Purpose This command configures IGMP snooping querier.
Syntax
config igmp_snooping querier [vlan <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 <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. Users may 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.
• 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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