IGMP snooping
This provides a method
for intelligently forwarding multicast packets within a Layer 2 broadcast domain. By
“snooping” the
IGMP (Internet Group Management Protocol) registration information, the device forms
a distribution list that determines which endstations receive packets with a specific
multicast address. Layer 2 switches listen for IGMP messages and build mapping tables and
associated forwarding filters. IGMP snooping also reduces IGMP protocol traffic.