Re: [B.A.T.M.A.N.] Debian Testing kernel module, BATMAN_V not supported

[Sven Eckelmann <sven@narfation.org>]

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On Freitag, 16. Februar 2018 18:52:45 CET Fox, Fred wrote:
> 
> When I try to set the routing algorithm to use BATMAN_V it returns the error:
> 
> [ 2327:090973] batman_adv: Routing algorithm 'BATMAN_V' not supported
[...]
> I am guessing that the option CONFIG_BATMAN_ADV_BATMAN_V=n was used when the kernel module was compiled.
> 
> - Is disabling BATMAN_V the default for most distributions?

Most likely. This option is disabled by default in the kernel and I would 
guess that most distributions don't manually enable it. An exception is 
OpenWrt/LEDE.

If you want that Debian enables the option then you have to sent a wishlist 
bug report [1] against the Linux package in Debian [2]. 

> - Is it because of stability issues with current wireless drivers (as reading the mailing list implies)?

Hm? Where did somebody write something like that?

The code itself is just not often used (afaik) and rather experimental.

There is one big problem with wifi driver: only wifi drivers with 
minstrel(-ht) support provide a useful *expected throughput* via cfg80211 - 
something which B.A.T.M.A.N. V requires to work correctly. So you are 
currently limited to drivers like ath5k/ath9k or mt76.

[...]
> In testing BATMAN_IV with my hardware, I noticed that as long as Node A could see Node C, it would communicate directly with it, even if the links between nodes A-B and nodes B-C had much higher throughput (tested with batctl tp). Would like to see if BATMAN_V would select the higher throughput path.

B.A.T.M.A.N. IV is not using a throughput based metric - instead it uses loss. 
You can try to tweak your wifi settings a little bit to help B.A.T.M.A.N. IV 
to calculate better routes - the most important setting is the multicast rate. 
Make sure that have increased it (a lot) to avoid sending the OGMs at the 
lowest rate (which has most of the time also the highest success rate).

But when you really need a throughput based metric then you should either 
rebuild your kernel with B.A.T.M.A.N. IV enabled or just build the external 
kernel module [3] with:

    make CONFIG_BATMAN_ADV_BATMAN_V=y
    sudo make CONFIG_BATMAN_ADV_BATMAN_V=y install
    sudo rmmod batman-adv
    sudo modprobe batman-adv

Check that you have really loaded correct module.

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Kind regards,
	Sven

[1] https://www.debian.org/Bugs/Reporting
[2] https://bugs.debian.org/cgi-bin/pkgreport.cgi?repeatmerged=yes&src=linux
[3] https://www.open-mesh.org/projects/open-mesh/wiki/Download#batman-adv-in-the-Linux-tree

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