Saturday, May 12, 2012

IGMP: Internet Group Management Protocol

  • IGMP is automatically enabled when PIM enabled.
  • IGMP enables the communication between multicast routers and their hosts.
  • Multicast routers uses the IGMP to send ip packets to what multicast groups on what interfaces.
  • Host Membership query:
    • Routers use the queries to discover the presence of multicast group member on a subnet.
    • general membership query is sent to the group address 0.0.0.0.
    • group specific query is sent to the group address that is required.
  • Host Membership Reports:
    • Hosts replies to queries.