According to my understanding of igmpv3_newpack(), the destination address should always be IGMPV3_ALL_MCR = 224.0.0.22. That is what I see in my testing.
However, your packet trace says 239.35.100.8. I don't know how the code that we touched would be generating an IGMPv2 packet with that destination address.
easy answer from wikipedia. 224.0.x.x is not the only multicast block
224.0.0.0 to 224.0.0.255 Local subnetwork 224.0.1.0 to 224.0.1.255 Internetwork control 224.0.2.0 to 224.0.255.255 AD-HOC block 1 224.3.0.0 to 224.4.255.255 AD-HOC block 2 232.0.0.0 to 232.255.255.255 Source-specific multicas 233.0.0.0 to 233.251.255.255 GLOP addressing 233.252.0.0 to 233.255.255.255 AD-HOC block 3 234.0.0.0 to 234.255.255.255 Unicast-prefix-based 239.0.0.0 to 239.255.255.255 Administratively scoped
Would it be possible to get a stack trace for the case where the source address is being cleared to 0.0.0.0 in your configuration?
you mean something like dumpstack and watching the flood comes over me?