[prev in list] [next in list] [prev in thread] [next in thread] 

List:       mythtv-users
Subject:    Re: [mythtv-users] IP_ADD_MEMBERSHIP Error
From:       Jan Ceuleers <jan.ceuleers () computer ! org>
Date:       2009-01-17 12:02:16
Message-ID: 4971C8C8.2020809 () computer ! org
[Download RAW message or body]

Matthias Burtscher wrote:
...
> 2008-12-21 18:15:37.353 QMulticastSocket: setsockopt - IP_ADD_MEMBERSHIP
> Error
...
> Maybe you can explain me, what this IP_ADD_MEMBERSHIP error means and
> how I can solve this problem.

Matthias,

I don't know whether any of this is actually your problem, but here's 
some background information for you.

The error message suggests that you have a multicast problem [1]. The 
multicast implementation in Linux includes IGMP [2], which provides a 
way for hosts to declare which multicast streams they're interested in.

The error message you are seeing says that your box is unable to declare 
such membership: the IP_ADD_MEMBERSHIP is a socket option [3].

Do you have a multicast route, as suggested in the multicast howto [4]? 
In my case, it's the following:

   route add -net 224.0.0.0/3 dev eth0

(Note that my box works just fine without this multicast route, both in 
native mode and as a UPnP server. The SSDP [5] part of UPnP uses 
multicasting, so I know that multicast can work without an route 
present. In any event this discussion is only relevant in case you have 
multiple interfaces, which my box does, and if you want to use another 
interface than the first-one for multicasting. So you may still need one 
if you have, for example, recently added an interface to your box).

Still, the troubleshooting section of the UPnP article on the MythTV 
wiki [6] also talks about a multicast route. The route shown above is 
more general than the 239.0.0.0/8 destination, so either should be fine.

Hope this helps.

[1]: http://en.wikipedia.org/wiki/Multicast
[2]: http://en.wikipedia.org/wiki/IGMP
[3]: http://www.sockets.com/ch16.htm#Multicast
[4]: http://www.tldp.org/HOWTO/Multicast-HOWTO-3.html
[5]: http://en.wikipedia.org/wiki/Simple_Service_Discovery_Protocol
[6]: http://www.mythtv.org/wiki/UPnP

Cheers, Jan
_______________________________________________
mythtv-users mailing list
mythtv-users@mythtv.org
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users

[prev in list] [next in list] [prev in thread] [next in thread]