All things related to multicast

[Nicholas J Humfrey <>]

Yes, I wasn't expecting this behaviour, but it certainly seems to  
happen. Could this be a known Cisco bug? Does it keep group  
membership state in a single table or multiple tables for each IGMP  
version?

nick.

On 5 Jul 2007, at 15:54, Stig Venaas wrote:

> Gary Parker wrote:
> > On 5 Jul 2007, at 14:26, Nicholas J Humfrey wrote:
> > > I find that these kinds of problems are the result of using a  
> > > mixture of IGMPv2 and IGMPv3. Mac OS X uses IGMPv2, and I guess  
> > > Vista should be using IGMPv3.
> > Cheers Nick, that makes sense.
>
> It might be the reason, but it should/does not make sense. When an
> IGMPv2 host sends IGMPv2 reports, the router should start doing IGMPv2
> queries and the IGMPv3 host should fall back to using IGMPv2 for that
> group as well. See section 7 of RFC 3376.
>
> It would be good to investigate this further and find out what is
> broken. This is supposed to work perfectly fine.
>
> Stig
>
> > > Btw; udp://@233.80.58.114:5000 is working fine here on my Mac! Is  
> > > this a Freewire channel?
> > Yes it is, Inuk multicast all their traffic over JANET and  
> > although the video is only viewable with their client or a lot of  
> > fiddling around with graphedit and DLLs in Windows the radio  
> > stations are all plain MPEG2 audio and can be listened to quite  
> > happily in VLC. We have a local SAP announcer on campus that lists  
> > all the Inuk radio streams for the use of people who can't/won't  
> > use the Freewire client.
> > Gary