1. Brief explanation of the internet group management protocols (IGMP) and Multicast listener Discovery protocols.
2. explain in short IGMP and MLD processing group members.
3. summarize IGMP and MLD processing by multicast routers.

 

1.

IGMP (Internet Group Management Protocol) is a networking protocol used by the hosts and the neighboring routers for the multicasting communication with the IP networks and makes effective use of the resources to send the messages or the data packets. Multicast networking can even have single or multiple senders and receivers, so IGMP may be mostly utilized in the streaming the video content, gaming, or online conferencing applications. This protocol is being used on the IPv4 networks, and multicasting on the IPv6 is handled by MLD(Multicast Listener Discovery ). The primary function of IGMP is to handle the dynamic groups for the IP multicast transmissions, which do not operate from the sending system themselves, but through the integrated routers. On one side, such receive the requests for participation from the receiver devices in the particular multicast community.

An IPv6 multicast group is really a group of receivers that want to receive a certain data source. This group does not have any physical or geographical boundaries-receivers may be placed everywhere on the Internet or on any private network. Receivers involved in collecting the data flowing to a specific community should join the group by signaling the local device. This signaling is accomplished by the MLD protocol. Devices just use MLD protocol to figure out if members of a community are available on the directly connected subnets. Hosts join the multicast communities by submitting messages to the MLD article. The network then transfers data to an infinite number of receivers, using just one copy of multicast data across each sub-net. IPv6 hosts wishing to accept traffic are defined as group members.

2.

A group member is a client who belongs to a specific multicast group. Which is practically speaking, implies that it has sent the messages asking it to receive whatever stream is intended for the group, and on receiving that stream, it will process it in some manner. 

In the IGMP, If a process on a host wishes to join a group, it passes a request to that host. Then the host adds the name of the requested process and also the name of the group to the list. If it's the first entry for such a specific group, the host will send a membership report message to the group's multicast router. If it is not the first entry for the requested group, there is no need to submit such a message. When a host feels no process that is interested in the group, it will send the leave report message.

When we allow MLD grouping, the system tracks MLD messages among receivers (hosts) and the multicast routers and utilizes the message content to create the IPv6 multicast routing tables, databases of the IPv6 multicast groups, and also the interfaces which are linked to members who are interested of each group.

3.

Snooping switches can only forward the IGMP Membership Reports to ports where the multicast routers are connected. The switch enabling IGMP snooping should maintain the list of the multicast routers and also the ports to which they have been linked. This list must be compiled by Snooping Switch to submit Multicast Router request messages as defined in the IGMP Multicast Router Discovery. Multicast Router Advertising messages received from and to other nodes can also be snooped.

The guidelines on monitoring and forwarding of data in the IGMP category can also refer to MLD with a few considerations. This ensures that the core features for intercepting MLD packets and constructing group members lists and the multicast router lists are just the same as the IGMP. In IPv6, the guidelines for packet forwarding are the more straight forward since MLD is required for the addresses with the scope 2 (link-scope) or the larger.