Robustness Value - Supermicro SSE-G24-TG4 Configuration Manual

IGMP Configuration Guide
Robustness value is 2
IGMP querying router is 2.2.2.2 (this system)
Fast leave is disabled on this interface
No multicast groups joined

1.7.3 Robustness Value

The robustness value can be fine-tuned to allow for expected packet losses on a subnet. The value of
this variable affects certain IGMP message intervals for IGMPv2 and IGMPv3 as specified below:
Group membership interval: Amount of time that must pass before a multicast router
•
determines that there are no more members of a group on a network.
Group membership interval = (Robustness value * query interval) + query response interval.
Other querier present interval: The robustness value is used to calculate the amount of time that
•
must pass before a multicast router determines that there is no longer another multicast router
that is the querier.
Other querier present interval = (Robustness value * query interval) + (0.5 * query response
interval).
Last-member query count: Number of group-specific queries sent before the router assumes
•
that there are no local members of a group. The number of queries is equal to the robustness
value.
In IGMPv3, devices send a state-change report whenever the interface state changes. The number of
times a state-change report is retransmitted is equal to the robustness value minus one.
The default robustness value is 2. You should increase this value if the subnet is expected to lose
packets.
Supermicro switches provide flexibility for users to configure different robustness value on different
interfaces.
Follow the steps below to change the robustness value on any interface.
Step Command
Step 1 configure terminal
interface <interface-type> <interface-id>
Step 2
or
interface range <interface-type> <interface-id> ....
Description
Enters the configuration mode.
Enters
mode.
interface-type – may be any of the
following:
gigabit ethernet – gi
extreme-ethernet – ex
qx-ethernet – qx
vlan
interface-id is in slot/port format for all
Supermicro L2/L3 Switches Configuration Guide
the interface configuration
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