Hi Robert,
On 06/01/18 01:23, Robert Bates wrote:
Hi Antonio,
This "ARP if unknown" idea has been suggested within the group, and it was referring to the notion of seeing if it was possible to have batman ARP if it receives a packet on bat0 destined for a client which is not in tt_global. I should not have mentioned that one, since Simon already confirmed that is not possible. Another idea I have heard mentioned is to implement a timer-based ARP mechanism - again, by some other component in the path on our AP. I'm not clear on exactly what the idea is there, or how it might work (need to sync up with that person once he's back from holiday).
Thanks for your other points. Regarding the potential for it to become racy to periodically read tt_local and probe clients, yes, the idea is to do so every 5 minutes, for example. We haven't discussed this much yet (for the same reasons - people are still out on holiday), but we would probably not attempt to distinguish between clients which need it, and those which do not. Though I suppose we could implement some logic to do it only if last seen time is greater than some value.
Very interesting point about an ICMP ping to the local client not generating packets which will come back through the bat0 interface. Hadn't considered that, thanks. Would you have a suggestion for a different type of probe?
If the "probing" software will be installed on each of your devices, then they could periodically ping some kind of central GW in the network. This would force a few unicast (and maybe broadcast) packets to cross the mesh and thus refresh the tt_local entry.
I would imagine this probe as some sort of "client keep alive" that tell the mesh "hey, I am still here".
Cheers,