Do not understanding difference between IGMPv2 and v3

[xine xine]

Hi !

I'm in my finaL preparation of my BSCI certification Exam, I do not understanding the difference between IGMPv2 and IGMPv3.  In Network academy documentation it's written :

Host H3 sends a join message with an explicit request to join sources in the source list. IGMPv3 uses a source list for source filtering, which allows a system to report interest in receiving packets only from specific source addresses or from all but specific source addresses that are sent to a particular multicast address. Multicast routing protocols can use that information to avoid delivering multicast packets from specific sources to networks where there are no interested receivers.

What I do not understand in this is the multicast trafficfor specific group which is not destinated on the subnet is never forward on the interface with IGMPv2.  What they are meaning in the previous quotes....

A rapid answer will appreciate, my exam is schedule at the and of the week !

Thanks a lot !

[rahurao · Accepted solution]

HI Xine,

As per the point for the version 2 is  concenred in IGMPv2 hosts send a Leave Group message to the reserved multicast address 224.0.0.2, the "all routers on this segment" address. You can understand the main difference between the IGMP versions through this:

Version 1, specified in [RFC-1112], was the first widely-deployed version and the first version to become an Internet Standard.

Version 2, specified in [RFC-2236], added support for "low leave latency", that is, a reduction in the time it takes for a multicast router to learn that there are no longer any members of a particular group present on an attached network.

Version 3 adds support for "source filtering", that is, the ability for a system to report interest in receiving packets *only* from specific source addresses, or from *all but* specific source addresses, sent to a particular multicast address.

I am attaching a powerpoint slide show for you to have a better understanding.

HTH

RAHUL