So are you running a DHCP forwarder on every node? (Or are you working with a layer-2 mesh, which is what Marek was alluding to?)
Not on every node. [...] We were working with a layer-2 mesh at the time.
Oh yeah, there should be no problem in a layer 2 mesh, if the mesh implements broadcast (or hacks in some ad hoc smarts related to DHCP). AHCP is only needed in a layer 3 mesh.
By the way, should this particular thread really be going to the babel-users list? If we're talking layer-2 we're talking BATMAN-adv, which is out of scope for that discussion list.
I don't think it is too outrageously off-topic. If the respectable recipients of this list object, we'll move to a more suitable forum. (There's unfortunately no suitable forum for protocol-agnostic discussions about mesh routing.)
-- Juliusz