D-Link xStack DES-3528 Series Cli Reference Manual page 202

xStack® DES-3528/DES-3552 Series Layer 2 Managed Stackable Fast Ethernet Switch CLI Reference Guide
config igmp_snooping querier
Purpose
This command is used to configure the IGPM snooping querier.
Syntax config igmp_snooping querier [vlan_name <vlan_name 32> | vlanid <vlanid_list> | all]
{query_interval <sec 1-65535> | max_response_time <sec 1-25> | robustness_variable
<value 1-7> | last_member_query_interval <sec 1-25> | state [enable | disable] |
version <value 1-3>}
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 - Specify the name of the VLAN for which IGMP snooping querier is to be
configured.
<vlan_name 32> - Enter the VLAN name here. The VLAN name can be up to 32 characters
long.
vlanid - Specify the VLAN ID for which IGMP snooping querier is to be configured.
<vlanid_list> - Enter the VLAN ID list here.
all - Specify all VLANs for which IGMP snooping querier is to be configured.
query_interval - (Optional) Specify the amount of time in seconds between general query
transmissions. The default setting is 125 seconds.
<sec 1-65535> - Enter the query interval value here. This value must between between 1
and 65535 seconds.
max_reponse_time - (Optional) Specify the maximum time in seconds to wait for reports from
members. The default setting is 10 seconds.
<sec 1-25> - Enter the maximum response time value here. This value must be between 1
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.
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 l3 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 l3 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.
•
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.
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