Multicast issue, interface not leaving Mutlicast Group

[Bjoern A. Zeeb]

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