docs: improve wired mesh documentation

Fixes #376

docs/features/mesh-on-wan.rst

-Mesh on WAN
-===========
-
-It's possible to enable the mesh on the WAN port like this::
-
-  uci set network.mesh_wan.auto=1
-  uci commit
-
-It may also be disabled again by running::
-
-  uci set network.mesh_wan.auto=0
-  uci commit
-
-site.conf
----------
-
-The optional option ``mesh_on_wan`` may be set to ``true`` (``false`` is the
-default) to enable meshing on the WAN port without further configuration.

docs/features/wired-mesh.rst

+Wired mesh (Mesh-on-WAN/LAN)
+============================
+
+In addition to meshing over WLAN and VPN, it is also possible to
+configured wired meshing over the LAN or WAN ports. This allows
+nodes to be connected directly or over wireless bridges.
+
+Mesh-on-WAN can be enabled in addition to the mesh VPN, so multiple nodes
+in the same local network that is used as VPN uplink can also mesh directly.
+Enabling Mesh-on-WAN should be avoided if the local network is also bridged with
+a WLAN access point, as meshing over batman-adv causes large amounts of
+multicast traffic, which will take up a lot of airtime.
+
+Enabling Mesh-on-LAN will replace the normal "client network" function
+of the LAN ports, as client network ports may never be connected (so care must be taken to always
+enable Mesh-on-LAN before connecting two nodes' LAN ports).
+
+Configuration
+~~~~~~~~~~~~~
+
+Both Mesh-on-WAN and Mesh-on-LAN can be configured on the "Network" page
+of the *Expert Mode* (if the package ``gluon-luci-portconfig`` is installed).
+
+It is also possible to enable Mesh-on-WAN and Mesh-on-LAN by default by
+adding ``mesh_on_wan = true`` and ``mesh_on_lan = true`` to ``site.conf``.
+
+Commandline configuration
+-------------------------
+
+Mesh-on-WAN
+...........
+
+It's possible to enable Mesh-on-WAN like this::
+
+  uci set network.mesh_wan.auto=1
+  uci commit
+
+It may be disabled by running::
+
+  uci set network.mesh_wan.auto=0
+  uci commit
+
+
+Mesh-on-LAN
+...........
+
+Configuring Mesh-on-LAN is a bit more complicated::
+
+  uci set network.mesh_lan.auto=1
+  for ifname in $(cat /lib/gluon/core/sysconfig/lan_ifname); do
+    uci del_list network.client.ifname=$ifname
+  done
+  uci commit
+
+It may be disabled by running::
+
+  uci set network.mesh_wan.auto=0
+  for ifname in $(cat /lib/gluon/core/sysconfig/lan_ifname); do
+    uci add_list network.client.ifname=$ifname
+  done
+  uci commit
+
+Please note that this configuration has changed in Gluon v2015.2. Using
+the old commands on v2015.2 will break the corresponding Export Mode
+settings.

docs/index.rst

@@ -25,7 +25,7 @@ Features
    features/configmode
    features/autoupdater
    features/private-wlan
-   features/mesh-on-wan
+   features/wired-mesh
    features/announce
    features/authorized-keys
    features/roles