Re: [magma] Question about IGMPv3 state change

Kunal Shah <> Mon, 07 March 2011 12:21 UTC

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From: Kunal Shah <>
To: Indranil Bhattacharya <>
Date: Mon, 7 Mar 2011 07:22:34 -0500
Thread-Topic: [magma] Question about IGMPv3 state change
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Subject: Re: [magma] Question about IGMPv3 state change
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Hi Indranil,

Consider this,

X= s1,s2
Y= s3,s4


Then X+A= s1,s2,s4,s5

s5 is in X even when it is not being blocked ??


From: Indranil Bhattacharya []
Sent: Monday, February 28, 2011 6:57 PM
To: Kunal Shah
Subject: Re: [magma] Question about IGMPv3 state change

Hi Kunal,

x = s1,s2
y= s3,s4

x+a = s1,s2,s3
y-a = s4
Does it answer your question?


On Tue, Feb 15, 2011 at 1:28 AM, Kunal Shah <<>> wrote:
Hi all,

I have a question about IGMPv3 state machine. If a group is in EX(X,Y) and a TO_IN(A) is received, the new state according to the RFC is EX (X+A, Y-A). I think this mean remove all the elements of A from Y and add all elements of A to X. This also implies that sources not removed from Y will still end up being added to X. My question is why cant we add only those elemets of A to X which are removed from Y as opposed to adding all the elements of A to X ??

If only the elements that are removed from Y are added to X, the new state would look like EX (X+(Y*A), Y-A).

Am I missing something here??


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