Wired mesh (Mesh-on-WAN/LAN)

In addition to meshing over WLAN and VPN, it is also possible to configure 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 replaces 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).

Wired mesh encapsulation

Since version 2018.1, Gluon supports encapsulating wired mesh traffic in VXLAN, a new standard with usecases similar to VLANs, but a much greater ID space of 24bit; in addition, VXLAN packets pass through VLAN-aware switches without any special configuration.

Encapsulating mesh traffic has two advantages:

  • By using a different VXLAN ID for each site and mesh domain, accidental wired mesh connections between nodes of different domains will be prevented. This has special importance when nodes migrate between domains automatically, as currently possible through different site-specific packages.
  • While batman-adv traffic does not interact with non-mesh traffic in the same wired network in any way (so Gluon nodes can mesh over existing wired networks), this is not the case for layer 3 mesh protocols like Babel. Encapsulating the traffic allows to distinguish mesh traffic from unrelated packets.

As enabling VXLAN encapsulation will prevent wired mesh communication with old nodes that do not support VXLAN yet, VXLANs can be enabled per-domain using the site configuration setting mesh.vxlan. VXLAN is enabled by default in multidomain setups; in single-domain site configurations, the mesh.vxlan setting is mandatory. We recommend to enable VXLAN encapsulation in all new sites and domains.

Non-encapsulated (“legacy”) wired meshing will be removed in a future Gluon release. We cannot give a concrete timeframe for the removal yet; a missing prerequisite is the implementation of a robust migration path for existing deployments.

Configuration

Both Mesh-on-WAN and Mesh-on-LAN can be configured on the “Network” page of the Advanced settings (if the package gluon-web-network 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

Enable Mesh-on-WAN:

uci set network.mesh_wan.disabled=0
uci commit network

Disable Mesh-on-WAN:

uci set network.mesh_wan.disabled=1
uci commit network

Enable Mesh-on-LAN:

uci set network.mesh_lan.disabled=0
for ifname in $(cat /lib/gluon/core/sysconfig/lan_ifname); do
  uci del_list network.client.ifname=$ifname
done
uci commit network

Disable Mesh-on-LAN:

uci set network.mesh_lan.disabled=1
for ifname in $(cat /lib/gluon/core/sysconfig/lan_ifname); do
  uci add_list network.client.ifname=$ifname
done
uci commit network

Please note that this configuration has changed in Gluon 2016.1. Using the old commands on 2016.1 and later will break the corresponding options in the Advanced settings.