+# config => {
+# ifaces => {
+# $ifname => {
+# <optional> exists => BOOL,
+# <optional> active => BOOL,
+# <optional> autostart => BOOL,
+# <auto> priority => INT,
+#
+# type => "eth" | "bridge" | "bond" | "loopback" | "OVS*" | ... ,
+#
+# families => ["inet", "inet6", ...],
+#
+# method => "manual" | "static" | "dhcp" | ... ,
+# address => IP,
+# netmask => SUBNET,
+# broadcast => IP,
+# gateway => IP,
+# comments => [ "..." ],
+#
+# method6 => "manual" | "static" | "dhcp" | ... ,
+# address6 => IP,
+# netmask6 => SUBNET,
+# gateway6 => IP,
+# comments6 => [ "..." ],
+#
+# <known options>, # like bridge_ports, ovs_*
+#
+# # extra/unknown options stored by-family:
+# options => { <inet options>... }
+# options6 => { <inet6 options>... }
+# }
+# },
+# options => [
+# # mappings end up here as well, as we don't need to understand them
+# [priority,line]
+# ]
+# }