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DGS-3600 Series Layer 3 Gigabit Ethernet Managed Switch CLI Manual
322 
config mld_snooping querier 
guarantees MLD snooping. 
Syntax 
config mld_snooping querier [vlan_name <vlan_name 32> | all] {query_interval <sec 1-
65535> | max_response_time <sec 1-25> | robustness_variable <value 1-255> | 
last_listener_query_interval <sec 1-25> | state [enable | disable] | version <value 1-2> 
}(1) 
Description 
This command configures the timer in seconds between general query transmissions, the 
maximum time in seconds to wait for reports from listeners, and the permitted packet loss 
that is guaranteed by MLD snooping. 
Parameters 
vlan_name
- Specify the name of the VLAN for which MLD snooping querier is to be 
configured. 
all
- Specify all VLANs for which MLD snooping querier is to be configured. 
query_interval
- Specify the amount of time in seconds between general query transmissions. 
The default setting is 125 seconds.. 
max_reponse_time
- Specify the maximum time in seconds to wait for reports from listeners. 
The default setting is 10 seconds. 
robustness_variable
- Provides fine-tuning to allow for expected packet loss on a subnet. The 
value of the robustness variable is used in calculating the following MLD message intervals: 
Group listener interval
- Amount of time that must pass before a multicast router decides 
there are no more listeners of a group on a network. This interval is calculated as follows: 
(robustness variable * query interval) + (1 * 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 * query interval) + (0.5 * query response interval). 
Last listener query count
- Number of group-specific queries sent before the router 
assumes there are no local listeners 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 loosely. 
last_listener_query_interval
- Specify the maximum amount of time between group-specific 
query messages, including those sent in response to done-group messages. You might lower 
this interval to reduce the amount of time it takes a router to detect the loss of the last listener 
of a group. 
state
- This allows the switch to be specified as an MLD Querier (sends MLD query packets) 
or a Non-Querier (does not send MLD query packets). Set to enable or disable. 
version <value 1-2>
- Specify the version of MLD packet that will be sent by this port. If a 
MLD packet received by the interface has a version higher than the specified version, this 
packet will be dropped. 
Restrictions 
Only Administrator and Operator-level users can issue this command. 
Example usage: 
To configure the MLD snooping querier: 
DGS-3627:admin# config mld_snooping querier vlan default query_interval 125 state enable 
Command: config mld_snooping querier vlan default query_interval 125 state enable 
Success. 
DGS-3627:admin# 
config mld_snooping mrouter_ports 
Purpose 
Used to configure ports as router ports.