D-Link DGS-3612G Product Manual - Page 276

xStack® DGS-3600 Series Layer 3 Managed Gigabit Ethernet Switch The states a computer will go through to join or to leave a multicast group are shown below: Figure 4- 115. IGMP State Transitions IGMP Version 3 The current release of the Switch now implements IGMPv3. Improvements of IGMPv3 over version 2 include: • The introduction of the SSM or Source Specific Multicast. In previous versions of IGMP, the host would receive all packets sent to the multicast group. Now, a host will receive packets only from a specific source or sources. This is done through the implementation of include and exclude filters used to accept or deny traffic from these specific sources. • In IGMP v2, Membership reports could contain only one multicast group whereas in v3, these reports can contain multiple multicast groups and multiple sources within the multicast group. • Leaving a multicast group could only be accomplished using a specific leave message in v2. In v3, leaving a multicast group is done through a Membership report, which includes a block message in the group report packet. • For version 2, the host could respond to a group query but in version 3, the host is now capable to answer queries specific to the group and the source. IGMP v3 is backwards compatible with other versions of IGMP. The IGMPv3 Type supported codes are shown below: Type Meaning 0x11 Membership Query 0x12 Version 1 Membership Report 0x16 Version 2 Membership Report 0x17 Version 2 Leave Group 0x22 IGMPv3 Membership Report 260