I believe we're setting the mesh_dhcp_range_start option incorrectly. The
wiki (
http://wiki.openwrt.org/doc/uci/dhcp) says it should be the offset
from the network address of the interface. So we should be able to set this
to, say, 50 for all nodes.
I can't seem remember how this worked in practice though. None of the
running nodes I have access to had any dhcp.leases for me to check.