[linux-dvb] Re: Routing multicast - broken linuxtv networking?

Luca Bertagnolio lucaberta at yahoo.com
Wed Jul 13 21:17:26 CEST 2005


Stonewall,

you're not the only one affected by this issue, as I too use IP
multicasting over DVB-S to receive the digital images of the
weather satellite over Europe, called MSG-1.

EUMETCast uses a few PIDs on a stream on the HotBird TV
satellite, but over the last couple of months me (and a friend
of mine) are not able to receive the IP multicast data
correctly, albeit it is shown by tcpdump and Ethereal.  This
happens on two different systems, one using a B2C2 DVB-S card,
and the other one with a budget NOVA DVB-S card.

Net effect is that the tq-recv application, which is used to
authenticate the user and "connect" to the session that sends
the data file, is not able to connect, and remains hanging
indefinitely.

I would really like to work to solve this issue, as it's quite
annoying to be forced to use an old kernel and dvb-kernel build
in order to keep receiving the weather satellite images.

Let me know if I can be of any help.

Bye, Luca

--- stonewall at inebraska.com wrote:
> Just tried bridging on a NOVA-S . . . same results as the B2C2
> card.  So, 
> something generic to all PCI network drivers broke bridging.
> 
> Stonewall
> 
> On Wednesday 13 July 2005 18:23, stonewall at inebraska.com
> wrote:
> > Julian - and others.
> >
> > It didn't work - but smcroute hasn't been updated since
> 2002; my guess is
> > it is not 2.6.x aware, or at least enabled to manipulate
> such.
> >
> > I didn't get any errors - it just doesn't route anything.
> >
> > Having said that, though, I did a test with a couple
> ethernet devices and
> > an external DVB-S modem.
> >
> > I was able to bridge them - using the 2.6.12.2 kernel - with
> no problem. 
> > This implies that the kernel bridge module maintainer is
> correct - that
> > something is broke in the 2.6.12.2 patched linuxtv-dvb
> network interfaces.
> >
> > I'm no kernel/driver hacker, by any means, but I will see
> what I can see. 
> > The change that broke this evidently occurred between
> 2.6.11.11 and
> > 2.6.12.2.
> >
> > My next test is to put my NOVA-S in this box, and see if it
> is purely the
> > new driver . . . or if it is the whole linuxtv-dvb network
> interface.
> >
> > Stonewall
> >
> > On Wednesday 13 July 2005 16:40, Julian Somers wrote:
> > > On Wed, Jul 13, 2005 at 03:06:55PM +0000,
> stonewall at inebraska.com wrote:
> > > > I am attempting to solve a problem that has began to
> plague me since
> > > > kernel version 2.6.11.
> > > >
> > > > I have a single DVB-S PCI card.  I receive six PIDs via
> that card for
> > > > news streaming (I'm a news junky).  The problem is that
> the multicast
> > > > streams on each of the six PIDs come from the same
> address -
> > > > 10.230.17.5.
> > > >
> > > > When I configure the dvb0_? devices, I had been using
> 10.230.17.20-25
> > > > up through kernel 2.6.11.  All worked fine - I was able
> to connect to
> > > > the six multicasts and see all six PIDs.
> > > >
> > > > Starting with 2.6.11, though, the routing table had
> become much
> > > > tighter, and it would then only stream through the first
> device I
> > > > configured for that subnet.  I can tcpdump all the
> devices and see the
> > > > stream packets - but I cannot "read" or forward on any
> except the first
> > > > I configure for that subnet.
> > > >
> > > > I initially tried:
> > > >
> > > > route add -net 224.0.6.10 netmask 255.255.255.255 dvb0_0
> > > > route add -net 224.0.6.11 netmask 255.255.255.255 dvb0_1
> > > > route add -net 224.0.6.12 netmask 255.255.255.255 dvb0_2
> > > > route add -net 224.0.6.13 netmask 255.255.255.255 dvb0_3
> > > > route add -net 224.0.6.14 netmask 255.255.255.255 dvb0_4
> > > > route add -net 224.0.6.15 netmask 255.255.255.255 dvb0_5
> > > >
> > > > This did not help - I still could only see the first
> device configured
> > > > for the subnet.  I configured each device for a
> completely different
> > > > subnet - each, and then attempted to route - still
> failure.
> > > >
> > > > I have read, unfortunately, that multicast cannot be
> routed.  Or at
> > > > least with the traditional methods.
> > >
> > > SMCRoute might provide a workaround: it can make static
> routes for
> > > multicast streams without IGMP. I think you can define
> source as well as
> > > destination interfaces. http://www.cschill.de/smcroute/
> > >
> > > Julian
> > >
> > > > So then I bridged all the devices together:
> > > >
> > > > brctl addbr br0
> > > > brctl stp br0 off
> > > > brctl addif br0 dvb0_0
> > > > brctl addif br0 dvb0_1
> > > > brctl addif br0 dvb0_2
> > > > brctl addif br0 dvb0_3
> > > > brctl addif br0 dvb0_4
> > > > brctl addif br0 dvb0_5
> > > > ifconfig dvb0_0 0.0.0.0 up
> > > > ifconfig dvb0_1 0.0.0.0 up
> > > > ifconfig dvb0_2 0.0.0.0 up
> > > > ifconfig dvb0_3 0.0.0.0 up
> > > > ifconfig dvb0_4 0.0.0.0 up
> > > > ifconfig dvb0_5 0.0.0.0 up
> > > > ifconfig br0 10.230.17.20
> > > >
> > > > And this worked through kernel version 2.6.11.11.  But,
> I use the
> > > > skystar2 card, and until 2.6.12.2, it's flaky.  Under
> 2.6.12.2, the new
> > > > b2c2_flexcop driver seems to work grand - but now
> bridging no longer
> > > > works.  I can bridge without errors, but now no data
> flows from any of
> > > > the PIDs.
> > > >
> > > > I corresponded briefly with the kernel bridge
> maintainer, and from the
> > > > initial conversation, I used macchanger to change the
> mac address for
> > > > each dvb0_? device so that each was unique within my
> system.  Still no
> > > > go.  The final statement from the bridge module
> maintainer is that the
> > > > networking device from linuxtv-dvb must be broke.
> > > >
> > > > All I want to do is be able to stream all six PIDs and
> see them
> > > > (outside of tcpdump).
> > > >
> > > > Final notes - multicast is compiled into the kernel, and
> ifconfig shows
> > > > MULTICAST on the devices.
> > > >
> > > > Any ideas?
> > > >
> > > > Stonewall
> > > >
> > > > _______________________________________________
> > > > linux-dvb mailing list
> > > > linux-dvb at linuxtv.org
> > > >
> http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
> > >
> > > _______________________________________________
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> > > http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
> >
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> > http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
> 
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