During the planning of an Internet Group Management Protocol (IGMP) network, a device is generally elected to act as a querier; the querier sends a query message to devices in the same multicast group on the IGMP network, and forwards data traffic.
When the devices on the network receive the query message from the querier, the devices compare their own addresses with the address of the querier, and the device with a lower address acts as the current querier. During the research and practice of the prior art, the inventor finds the following problems in the prior art: During the network planning, the network planner generally elects a device with the lowest address to act as the querier; when a new device is added on the network or the address of a device on the network is modified, the new device or the device whose address is modified may become the current querier when receiving a query message if the address of the new device or the device whose address is modified is lower than the address of the current querier. In this case, the current querier on the network may be changed frequently, causing instability of the network.