The protocol number of IGMP (Internet Group Management Protocol) is 2. This number is assigned to IGMP in the IP protocol header to identify and distinguish it from other protocols at the Network layer (Layer 3) of the OSI model.
IGMP is primarily encapsulated within IP packets, specifically IPv4, and it operates as a part of the IP protocol suite. Its protocol package consists of messages exchanged between hosts and multicast routers to manage membership in multicast groups. These messages include Join Group, Leave Group, and Group Query messages, allowing hosts to signal their interest in receiving multicast traffic for specific groups.
IGMP operates at Layer 3 (Network layer) of the OSI model. It is designed to manage multicast group memberships within a network, facilitating the efficient delivery of multicast traffic. By enabling hosts to join and leave multicast groups dynamically, IGMP supports the distribution of multicast data streams across networks.
The port number used for IGMP is 0. Unlike many other protocols that use specific port numbers for communication, IGMP does not rely on port numbers for its operation. Instead, it uses IP addresses and specific IGMP message types to manage multicast group memberships and multicast traffic flow within a network.
IGMPv3 (Internet Group Management Protocol version 3) is an extension to IGMP that introduces enhancements for managing multicast group memberships in IPv4 and IPv6 networks. It improves on previous versions by adding support for source-specific multicast (SSM) and allowing hosts to specify which sources they want to receive multicast traffic from. IGMPv3 helps optimize network bandwidth and reduce unnecessary traffic by providing finer control over multicast group subscriptions and data delivery.