Users Guide

• Reporting is more efficient and robust: hosts do not suppress query responses (nonsuppression helps
track state and enables the immediate-leave and IGMP snooping features), state-change reports are
retransmitted to insure delivery, and a single membership report bundles multiple statements from a
single host, rather than sending an individual packet for each statement.
The version 3 packet structure is different from version 2 to accommodate these protocol enhancements.
Queries are still sent to the all-systems address 224.0.0.1, as shown in the following illustration, but reports
are sent to the all IGMP version 3-capable multicast routers address 244.0.0.22, as shown in the second
illustration.
Figure 49. IGMP Version 3 Packet Structure
Figure 50. IGMP Version 3–Capable Multicast Routers Address Structure
Internet Group Management Protocol (IGMP) 450