On Thursday, 26 July 2018 14:14:14 HKT Nicu Pavel wrote:
I'm also not sure about the originators list, if you look at the attached file, all originators TQ is pretty low and also each originator has all other hosts as NextHop. Not sure if this is correct or can affect. All these 30 hosts are pretty close to one another.
It might be (as Linus has suggested) related to poor connectivity / airtime overcrowding. Though for that to be the case, I'd expect a more gradual packet loss symptoms - not a complete collapse when you switch from 31 to 32 devices.
If you check the mailing list archives you will see the wifi driver issue coming up on a regular basis. This example discussion is merely a few days old:
https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2018-July/017952.html
Yes, I found that thread, but problem is quite different as with RealTek chipsets seems like nothing really works.
My point was rather to consider that the WiFi driver has its fingers in the pot too. It is somewhat unlikely that your issues are exactly the same as mentioned in this randomly selected thread.
By the way, searching for 'brcmfmac adhoc' returns quite a number of hits mentioning complaints concerning Rasberry PIs. Have you tried running your setup without enabling batman-adv at all ? Since all of the devices are so close to each other batman-adv is not needed. Pure adhoc mode will work just fine. This test will help you figuring out whether the ICMPv6 misbehavior is related to batman-adv or not.
Cheers, Marek