Isolating certain clients in mesh batman-adv

I am struggling to find anything on this, and maybe it's not possible (I am still an OpenWRT noob) but in my head it seems possible:

I have several robots I want to mesh together to a base-station LAN. They all have a static local subnet that mirrors one-another (compute, cameras, etc.), while the base station exists on a separate LAN/WLAN with DHCP. When I mesh them together, they collide horrendously and I'll get cameras from one robot streaming to another, etc.. They are wired in via eth1 to the mesh node with a bridge from bat0 to eth1 (this seems like a problem)

I am not able to figure out how to masquerade the IP's at the mesh node; I want the robot subnet to reach the internet ideally but primarily clients on the base station subnet. I do not want the robot subnets to be able to talk to each other, but still have them mesh (so I can extend the range of one with another etc)

Our architecture on the robot is dumb switch, single NIC companion computer, and a few static IP cameras, so ideally we solve this in the mesh radio. I don't really want each robot to be on separate VLANs either.

I hope you guru's have some ideas. Let me know which config files I should share. Thanks in advance

Some questions:

  1. Do you mean the robots all have identical configurations?

  2. Is the "companion computer" on each robot running OpenWrt and if not, what is supporting the mesh connection?

  3. How fast do the robots move? A mesh is not designed for rapid movement of nodes in the way a mobile phone network is.

1: Yes the robots have identical configurations.
2: Companion computer is running linux, we have a separate embedded device based on Qualcomm Atheros QCA9533 running OpenWRT with one ethernet interface. They are connected via a dumb switch (as well as the IP cameras)
3: They max out at 14kph

This is ~4 metres per second. Is this relative to the base station?
If it is, then this is problematic to a mesh. Firstly, the robots will very rapidly go out of range. Secondly, by default, mesh protocols take a few seconds or even longer to readjust to movement of mesh nodes. So you might have a more fundamental problem here.

If the relative speeds between robots is low, the "mesh" backhaul will go with the robot "swarm" and leave the base station behind. :scream:

Is your separate embedded device running mainstream OpenWrt or some unofficial fork?

Going back to your original question - your embedded device is a kind of back to front "mesh portal".

A mesh portal is defined as a device that uses ethernet as an uplink (eg to an Internet feed) nat-routed to a wireless mesh backhaul interface.

You want a mesh backhaul interface nat-routed to an ethernet downstream (the robot lan).

This is not a common requirement, explaining why you have not found any discussion of it.

Yes it is possible, of course. But with your embedded device? We would need more detail of it to see if it is feasible - assuming a mesh is suitable for your use case in the first place.