Owners manual

DGS-1510 Series Gigabit Ethernet SmartPro Switch CLI Reference Guide
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suppression time expired. For report or leave messages to the same group, only one report or leave
message is forwarded. The remaining report and leave messages are suppressed.
Example
This example shows how to enable report suppression on VLAN 1.
Switch# configure terminal
Switch(config)# vlan 1
Switch(config-vlan)# ip igmp snooping report-suppression
Switch(config-vlan)#
31-12 ip igmp snooping robustness-variable
This command is used to set the robustness variable used in IGMP snooping. Use the no form of this
command to revert to the default value.
ip igmp snooping robustness-variable VALUE
no ip igmp snooping robustness-variable
Parameters
VALUE
Specifies the robustness variable. The range is from 1 to 7.
Default
By default, this value is 2.
Command Mode
Interface Configuration Mode.
Command Default Level
Level: 12.
Usage Guideline
This command is only available for VLAN interface configuration. The robustness variable provides fine-
tuning to allow for expected packet loss on an interface. The value of the robustness variable is used in
calculating the following IGMP message intervals:
• Group member interval – The 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 – The 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 – The 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.
Users can increase this value if a subnet is expected to be loose.
Example
This example shows how to configure the robustness variable to be 3 on interface VLAN 1000.