Re: [B.A.T.M.A.N.] batman-adv on different archs

Marek Lindner
2010-01-18T11:42:05Z

Hi,

> The problem comes when I try to add my little ARM based linux box onto the
> group. Again same sources used (latest stable from the wiki),
> crosscompiles fine and I can load the module as normal on the box. Setup
> goes as it should on both the device and the laptop, and both systems
> seems to be running smoothly. But my laptop can only see the other laptop,
> and the device doesn't see anyone. The wireless net is working and I can
> ping each device directly if I assign IP's to the 'real' interfaces, but
> through bat0 nothing is found. Any idea what is going wrong?

as soon as normal pings work batman-adv should also work. From what you
describe I can't see any obvious mistake. Did you try to peek into the debug
logs or capture some packets to see whether the nodes are communicating
correctly ?

> I've also played with the batman daemon on the device, with it I the laptop
> and device can see each other just fine. The problem there is that
> apparently it doesn't really support multicast forwarding? i.e. If I have
> 3 devices A-B-C, where A does not have direct link to C (batman routes
> through B), sending a multicast from A can be received in B and vice
> versa, also same for C-B, but no messages from A to C. Will I have the
> same problem with batman-adv? Or can this be fixed on the daemon?

The daemon operates on layer 3, therefore multicast forwarding can't work.

Some other layer 3 routing daemons try to support multicast by hacking a layer
2 tunneling into the daemon. The performance is poor at the expense of CPU
load but give it a try yourself in case this is no problem.

However, batman-adv supports multicast out of the box.

Regards,
Marek