Re: Booting 2.5.63 vs 2.4.20 I can read multicast data

brian@worldcontrol.com
Thu, 6 Mar 2003 01:49:11 -0800


> On Tuesday, 4 March 2003, brian@worldcontrol.com wrote:
> > The apps I have vlc, and mpeg2dec (with mods) cannot read multicast
> > data under 2.5.63, but both work under 2.4.20.
> >
> > I also have some PERL tools which do multicasting stuff and they don't
> > work any longer either.
> >
> > However, I added 'eth0' to the IO::Socket::Multicast::mcast_add()
> > call and now the data is showing up.
> >
> > I believe this means back in the C/C++ paradigm you can't rely on
> > INADDR_ANY to do the right thing. So you may have to set the specific
> > IP of the interface you want your multicast data to come from in
> > imr_interface.s_addr of the struct ip_mreq you pass in via setsockopt(
> > sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, ...
> >
> > I'll give this a try and let you know what I find.
>
On Wed, Mar 05, 2003 at 09:25:20AM +0100, Niels den Otter wrote:
> But lot of multicast applications use INADDR_ANY and most don't provide
> an option to choose a specific interface. So I really think that the
> kernel should bind the application to an ethernet interface and not to
> the loopback interface to make them work.

I have to agree that the kernel is broke. After further reading
the expected behavior looks well defined, and the apps along
with my code are designed properly.

> Can you please check if it tries to bind to the loopback interface when
> using INADDR_ANY by checking 'netstat -n -g' output?

I will do my best to give it a try.

-- 
Brian Litzinger
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