Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 1 Lesson 9 Internet Group Management Protocol (IGMP)

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 2 Internet Group Management Protocol (IGMP) IP multicasting overview Host and router support for IP multicasting IGMP version 1 IGMP version 2 IGMP version 3 Windows support for IGMP

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 3 IP Multicasting Overview One-to-many delivery w/o broadcasting Class D IP multicast addresses /4 Address range of to Specific address is a group address Multicast or host group The set of hosts listening on a specific IP multicast address Group can be any size Members located anywhere on the IP internetwork

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 4 Host Support for IP Multicasting Sending IP multicast traffic Host determines destination multicast traffic Multicast route(s) in IP routing table ARP not used when sending Receiving IP multicast traffic Maintain multicast MAC address table entries Send IGMP Host Membership Report message is sent to inform local routers to forward the host group traffic to the network segment of the listening host

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 5 Router Support for IP Multicasting Listen for IGMP Host Membership Report messages sent from hosts on local network segments Track and maintain group membership for hosts on local network segments Communicate host group membership information to neighboring routers Listen for all IP multicast traffic on all attached network segments Forward IP multicast traffic with a valid TTL on appropriate network segments

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 6 Multicast-Enabled IP Internetwork Multicast routing protocols IGMP Host Membership Report IP multicast traffic Listening host Sending host

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 7 IGMP Message Encapsulation IP HeaderIGMP Message IP Datagram Network Interface Header Network Interface Trailer Network Interface Layer Frame

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 8 IGMP version 1 (IGMPv1) Two types of IGMPv1 messages Host Membership Report  Used by a host to report host membership in a specific group Host Membership Query  Used by a router to query host group membership on a network segment

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 9 IGMPv1 Message Structure Version Type Unused Checksum Group Address = 1 Type = 1: Host Membership Query Type = 2: Host Membership Report = 1 or 2

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 10 IGMP version 2 (IGMPv2) Changes from IGMPv1 The Leave Group message The Group-Specific Query message The election of a multicast querier New format for the IGMPv2 Host Membership Report message

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 11 IGMPv2 Message Structure Type Maximum Response Time Checksum Group Address Type = 17: Host Membership Query Type = 22: IGMPv2 Host Membership Report Type = 23: Leave Group Message = 17, 22, or 23

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 12 IGMP version 3 (IGMPv3) Supports multicast source-specific reports and queries IGMPv3 Host Membership Report message can specify: The list of multicast sources from which the host can receive the multicast packets (the include list) or The list of the multicast sources from which the host must not receive multicast packets (the exclude list)

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 13 IGMPv3 Host Membership Query Type Maximum Response Time Checksum Group Address Reserved Supress Router-Side Processing Querier’s Robustness Variable Querier's Query Interval Number of Sources Source Address 1... = 0x11

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 14 IGMPv3 Host Membership Report Type Reserved Checksum Reserved Number of Group Records Group Record 1... Group Record N = 0x22...

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 15 IGMPv3 Host Membership Report Message Group Record Record Type Auxiliary Data Length Number of Sources Multicast Address Source Address 1 Source Address n Auxiliary Data...

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 16 Windows Support for IGMP TCP/IP Protocol IGMPv3-capable host Mapping of IP multicast addresses for Ethernet, FDDI, and Token Ring Multicast forwarding based on the entries in the TCP/IP multicast forwarding table Routing and Remote Access service Limited multicast forwarder using IGMPv1, IGMPv2, or IGMPv3 to track local group membership IGMP routing protocol component  Interfaces set for IGMP Router Mode or IGMP Proxy Mode

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 17 IGMP Router Mode and Proxy Mode IP multicast-enabled internetwork Sending or receiving host Windows Server 2003 router Neighboring IP multicast-enabled router IGMP proxy mode interface IGMP router mode interface

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 18 Review IP multicasting overview Host and router support for IP multicasting IGMP version 1 IGMP version 2 IGMP version 3 Windows support for IGMP