IGMP snooping and IGMP snooping proxy have the same functions but different principles. IGMP snooping is used to obtain user information by snooping IGMP messages, whereas IGMP snooping proxy snoops and processes IGMP messages sent from user hosts before sending them to an upper-layer router.

Compared with a device enabled with IGMP snooping, a Layer 2 device enabled with IGMP snooping proxy plays the role of a router at the user side and periodically sends Query messages, and plays the role of a host at the network side and sends IGMP Report or Leave messages to its upstream device. Compared with IGMP snooping, IGMP snooping proxy suppresses multicast traffic flooding on a Layer 2 network and reduces the number of protocol packets and network loads. An IGMP snooping proxy-enabled device needs to maintain the member port entry database and function as a proxy of a router. As a result, IGMP snooping proxy increases device implementation complexity and device resource consumption.

S7700, S9700