IGMP

• IGMP manages multicast group membership on “last hop” networks

• • Between a host and its local router
  • TTL must be set to 1
  • The router alert IP option should be used

• Like ICMP it is on layer 3 but encapsulated by IP

• Also like IGMP, it is connectionless and unreliable

• Technically, IGMP is required for all IP hosts

• • In practice it is not necessary unless multicasting support is needed