receiving multicast packets

Posted on 2006-05-16
Last Modified: 2010-04-21
Let's say my application wants to receive two different multicast streams.  One is broadcast to and one to

I have two different sockets (on different threads) which go through the following process:
   setsockopt() // to allow binding on the same port
   bind() // bind to port 9020
   setsockopt() // to join the multicast group for the multicast address we want to listen to
   recvfrom() // call this in a loop to get our multicast packets

The problem I'm having is that each socket is receiving packets from BOTH multicast groups!  Shouldn't the socket only receive packets from the multicast address that is joined to via setsockopt?

Also it should be noted that if the two multicast streams I'm receiving are on different ports, then this problem doesn't exist.
Question by:lwinkenb
    LVL 3

    Expert Comment

    can you post the snippet of the sequence so I can look at the docs......I haven't written code listening to
    multicast in a long time...

    Just wanna check to see what you're doing...

    If you have a test program, that would be even better!!

    LVL 5

    Author Comment

    I ended up figuring out the problem.  As it turns out, I had to bind to the multicast address in order to only receive those multicast packets.  What threw me off was that all the example code I saw always bound to INADDR_ANY.

    Accepted Solution

    Closed, 500 points refunded.
    Community Support Moderator
    replacement part #xm34

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