Multicast issue, interface not leaving Mutlicast Group

[Abelenda Diego]

On Sun, 09 Aug 2020 13:55:02 +0000
"Bjoern A. Zeeb" <bzeeb-lists at lists.zabbadoz.net> wrote:

> On 8 Aug 2020, at 12:31, Abelenda Diego wrote:
> 
> > On Sat, 8 Aug 2020 12:54:37 +0200
> > Hans Petter Selasky <hps at selasky.org> wrote:
> >  
> >> On 2020-08-07 15:25, Abelenda Diego wrote:  
> >>> Hello,
> >>>
> >>> I have discovered that I had a multicast issue for years I did not 
> >>> know
> >>> about. I use a FreeBSD (opnsense) setup as router for my home 
> >>> network and
> >>> have igmpproxy for IPTV. Somehow everything seems to work, until I 
> >>> realized
> >>> that my ISP was making a DoS with multicast. It is pretty much what 
> >>> was
> >>> described years ago here:
> >>> https://forum.netgate.com/topic/62591/igmp-issues-causing-isp-to-perform-multicast-dos-on-my-pfsense/7.
> >>> But the solution of not using FreeBSD seem weird. So dug a lot 
> >>> learning
> >>> about Multicast IGMPv{2,3} etc in the process. Here is an abstract 
> >>> of what
> >>> I found:  
> >>
> >> Which version of FreeBSD is this (uname -a) ?
> >>
> >> There has been some fixes in the multicast area from time to time, 
> >> and
> >> you should make sure you've got all the fixes incorporated in the 
> >> kernel
> >> you are using, typically by testing a kernel based on a -stable or
> >> -current branch of FreeBSD.
> >>
> >> --HPS
> >>  
> >
> > Hello,
> >
> > This is opnsense, so it is not like I can change kernel as I want. 
> > Moreover the
> > kernel used by opnsense has some patches for stf 6rd support for 
> > example,
> > things like that.
> >
> > Anyway, the kernel I use is:
> >
> > FreeBSD $hostname 12.1-RELEASE-p7-HBSD FreeBSD 12.1-RELEASE-p7-HBSD #0 
> >  427d53bc125(stable/20.7)-dirty: Sun Jul 26 05:51:42 CEST 2020     
> > root at sensey64:/usr/obj/usr/src/amd64.amd64/sys/SMP  amd64
> >
> > But from what you are asking, it seems you suggest my issue is kernel 
> > related
> > and in no way a userspace problem. So I cannot do anything to mitigate 
> > the
> > issue?
> >
> > BTW I said reset the interface fixed the issue, but in fact, I need to 
> > reboot,
> > I found no way to clear the multicast group memberships.  
> 
> 
> Is this related to:
> 
> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=248512  and the there 
> referenced other bugs?
> 
> 
> /bz


Hello,

Yes seems to be that, even the address already in use error is present in the
log of imgpproxy.

Thank you for pointing that. I will try to make opnsense include this patch
quickly.

Best regards,
Diego Abelenda
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