The Homenet (hnet) protocol and this documentation is under development (late 2016).
See the Forum article that describes their state.

The Homenet Control Protocol (HNCP) automatically manages IPv4 and IPv6 address assignment, routing, DNS, SD (ZeroConf/mDNS) and border firewalling between multiple routers in a “home network”. It is specified as a set of RFCs to implement a minimalist state synchronization protocol for Homenet routers.
Read the materials on the Homenet web site

hnet-full package installs hnetd to implement HNCP protocol, there is also luci-app-hnet, a luci webgui package to control it. Note: We strongly recommend you install ipset before installing hnet-full

Protocol "hnet"

Name Type Required Default Description
mode string no auto Interface mode. One of external, guest, adhoc or hybrid.
ip6assign integer no 64 IPv6-prefix size to assign to this interface if internal.
ip4assign integer no 24 IPv4-prefix size to assign to this interface if internal.
dnsname string no <device-name> DNS-Label to assign to interface.
Technical Reference