IGMP on FreeBSD-12.1

[Victor Gamov]

Hi All

I have FreeBSD 12.1-STABLE r354850

When I started
ffmpeg -i 
'udp://232.232.9.57:3344?localaddr=10.200.207.35&source=10.200.205.2'

then IGMP-Join sended out and ifmcstat reports about 232.232.9.57 on 
proper interface.

I kill ffmpeg but ifmcstat still reports about 232.232.9.57 on interface.

Any following ffmpeg start does not generate IGMP-Join as I understand 
because kernel think it still joined to this multicast.


Then I start this scenario on FreeBSD 11.3-STABLE #1 r354778 then group 
subscription immediately removed from interface at the moment when 
ffmpeg killed.



More things.  When I request multicast on 11.3 from 12.1 then 11.3 
respond to General-query  like this:
=====
10.200.207.42 > 224.0.0.22: igmp v3 report, 1 group record(s) [gaddr 
232.232.99.7 is_in { 10.200.208.33 }]
=====


When I request multicast on 12.1 from 11.3 then 12.1 respond to 
General-query  like this:
=====
10.200.207.35 > 224.0.0.22: igmp v3 report, 1 group record(s) [gaddr 
232.232.9.44 to_ex { }]
=====


And when ffmpeg started on 12.1 first time as following
ffmpeg -i 
'udp://@232.232.9.44:3344?localaddr=10.200.207.35&source=10.200.205.2'

then 12.1 generates IGMP-Join without source:
=====
10.200.207.35 > 224.0.0.22: igmp v3 report, 1 group record(s) [gaddr 
232.232.9.44 to_ex { }]
=====


So, I assume 12.1 have some problem with IGMP

-- 
CU,
Victor Gamov