Re: [B.A.T.M.A.N.] [batman-adv] Does batman-adv works perfectly?

[Sven Eckelmann <sven@narfation.org>]

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On Donnerstag, 6. April 2017 10:32:29 CEST Xuebing Wang wrote:
> Hi community,
> 
> We have batman-adv working on OpenWRT Chaos Calmer.
> - Atheros ar9331 MIPS platform + built-in ath9k WiFi
> - batman-adv version 2016.1

Please update your batman-adv version. This one is known to have problems
which can cause crashes or memory corruptions.

If you are using the Chaos Calmer packages version 2016.1-3 then you should 
already have some of the fixes (I think all fixes up to 2016.3 or so). But no 
one is updating the Chaos Calmer branch in the openwrt-routing packages feed 
anymore. And I doubt that anyone will do that now because LEDE 17.01 was 
released a while ago.

[...]
> - Wireless interface MTU = 1532, adhoc network encryption "psk2-ccmp"
[..]
> We have batman-adv running on 10+ sites. For each site, there are 10-20 
> nodes in the mesh network.
> 
> batman-adv runs almost perfectly (*almost*). Occasionally (occurrence 
> rate is low), node drops off the batman-adv / adhoc mesh.
> - Sometimes, node can recover (re-joins the mesh network automatically), 
> but not always.

This sounds like problems in the wifi stack/hw. batman-adv is not handling 
adhoc or encryption - it is simply using the links which are provided by your 
wifi stack/hardware.

Your description therefore looks more like you should fix your wifi. I don't 
know why you have low rates but the IBSS problems with enabled encryption 
could be caused by an HW issue. You should check out a workaround to refresh 
the HW key cache [1] when incoming packets cannot be decrypted anymore.

> Any suggestions? Does batman-adv works perfectly in the field (i.e. 
> running for 1 year with 100+ nodes without any issues)?

There are a lot of other components which will fail during that time. For 
example your wifi stack

> What about I use one node as Master, and other nodes ping this Master 
> every 10s (or 30 seconds) (to keep mesh from inactivity)? Does this help?

I have absolutely no idea against what this should help.

Kind regards,
	Sven

[1] https://patchwork.kernel.org/patch/9381651/

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