How are the IP address ranges allocated to the backhaul interfaces?
The backhaul interface is configure using zeroconf. Zeroconf is short for zero configuration IP networking, a method of network devices via an Ethernet cable without requiring configuration and administration. Zeroconf is able to allocate addresses without a DHCP server, translate between domain names and IP addresses without a DNS server, and find services, such as a printer, without a directory service. For additional information see Auto configuration for IP Networking: Enabling Local Communication.