Does an S series switch enabled with IGMP snooping querier participate in IGMP querier election

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After IGMP snooping querier is enabled on an S series switch, the switch periodically sends Query messages to users in a VLAN but does not participate in IGMP querier election or forward Query messages to a VLAN.
Layer 2 multicast querier is used when the switch connects to no upstream Layer 3 device or when the IGMP querier function is not enabled on the upstream Layer 3 device. If an IGMP querier exists on the network, do not enable the IGMP snooping querier function on the switch. This is because this function affects querier election on the upstream Layer 3 device and causes multicast service failures.

Other related questions:
How does an S series switch elect an IGMP querier
When a host subnet is connected to the interfaces on multiple devices, to avoid data conflict, only one interface is allowed to send Query messages. This interface is the querier. The other interfaces running IGMP can receive the IGMP messages in this subnet. In IGMPv1, the querier is elected by a multicast routing protocol such as PIM. In IGMPv2 and IGMPv3, the switch interface with the lowest IP address acts as the querier.

How does IGMP elect a querier from multiple devices on a shared network segment
When a host network segment is connected to the interfaces on multiple devices, to avoid data conflict, only one device interface is allowed to send Query messages. This interface acts as the querier. The other device interfaces that run IGMP can receive to the IGMP messages on the network segment. In IGMPv1, querier selection depends on the multicast routing protocol, such as PIM. In IGMPv2 and IGMPv3, the device interface with the lowest IP address acts as the querier on the network segment.

What is the function of the interval for sending Query messages on an S series switch?
For an S series switch, the interval for sending Query messages configured in a VLAN using the igmp-snooping query-interval command is used to: - Control the interval at which Query messages are sent after the querier function is enabled in the VLAN. - Calculate the aging time of dynamic member ports using the following formula: Aging time = Robustness variable x Query interval + Maximum response time Therefore, the interval is useful even when IGMP snooping querier is not enabled. In addition, you must configure the same interval on all devices when configuring IGMP snooping. Otherwise, some user-side interfaces may be incorrectly deleted, causing multicast forwarding interruption.

How IGMP messages are transparently transmitted on an S series switch enabled with IGMP snooping
After global IGMP snooping is enabled on a switch, the switch sends all the IGMP messages received from a VLAN to the CPU for processing. If the multicast service is not configured in a VLAN and the switch needs to directly forward the IGMP messages of this VLAN without sending them to the CPU, run the protocol-transparent command in the VLAN view to enable transparent transmission of protocol packets. S series fixed switches support transparent transmission of protocol packets starting from V200R001, and only the S3700HI, S5710EI, S5720EI, S5700HI, S5710HI, S5720HI, S6700EI, andS6720EI support this function. S series modular switches support this function.

Difference between IGMP snooping and IGMP snooping proxy on an S series switch
IGMP snooping and IGMP snooping proxy have the same functions but different mechanisms. IGMP snooping obtains required information by listening to IGMP messages; IGMP snooping proxy intercepts and suppresses IGMP requests of terminal users, and then forwards the requests to the router. The Layer 2 network device with IGMP Snooping Proxy configured functions as a server on the user side. It periodically queries user information. On the network side, this switch functions as a client and reports user information after receiving query messages. Therefore, IGMP snooping proxy can not only suppress multicast packets on Layer 2 network, but also reduce the total number of protocol packets on the network. The proxy router is required for maintaining and calculating entry status changes, so the implementation is more complex and the cost is added.

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