Simple definition
IGMP Snooping is a concept or mechanism used in a network & multicast to limit the IPv4 multicast to really interested ports.
Technical definition
In a business environment, IGMP Snooping mainly intervenes to limit the IPv4 multicast to the ports really interested. Its implementation depends on the architecture, equipment and security policies in place.
What is it used for?
limit IPv4 multicast to really interested ports.
Practical example
one switch sends an IPTV stream only to the members of the group.
Common issues
- quarier absent
- Multicast flood
- VLAN incorrect
Key takeaway: Always adapt the diagnosis to the product version and the architecture actually deployed.