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How does IGMP snooping works?
IGMP snooping works with Layer 2 interfaces and RVIs to forward multicast traffic in a switched network. When the device receives a multicast packet, its Packet Forwarding Engines perform a multicast lookup on the packet to determine how to forward the packet to its local interfaces.
What is the difference between IGMP and IGMP snooping?
IGMP is a network layer (Layer 3) protocol used to establish membership in a Multicast group and can register a router to receive specific Multicast traffic. IGMP snooping checks IGMP packets passing through the network, picks out the group registration, and configures Multicasting accordingly.
Is Igmp UDP or TCP?
Just like ICMP, IGMP does not use a transport layer protocol such as TCP or UDP.
What is the purpose of IGMP snooping on a network?
Purpose. IGMP snooping is designed to prevent hosts on a local network from receiving traffic for a multicast group they have not explicitly joined. It provides switches with a mechanism to prune multicast traffic from links that do not contain a multicast listener (an IGMP client).
Do you need a multicast router for IGMP snooping?
In order for IGMP, and thus IGMP snooping, to function, a multicast router must exist on the network and generate IGMP queries. Without a querier IGMP membership reporting may be incomplete and the tables associating member ports and multicast groups are potentially incomplete and snooping will not work reliably.
Is there a way to disable IGMP snooping in Junos?
If no snooping is configured, the IRB output interface list is expanded to all Layer 2 interfaces in the bridge. The Junos OS does not support IGMP snooping in a VPLS configuration on a virtual switch. This configuration is disallowed in the CLI.
Where does IGMP snooping take place in Layer 2?
Essentially, IGMP snooping is a layer 2 optimization for the layer 3 IGMP. IGMP snooping takes place internally on switches and is not a protocol feature.