6LBR Interface Configuration

Note: This page is only relevant for Linux based 6LBR

On Linux platform, you need to link the 6LBR process to your LAN Network, in order to do so you have three possibilities :

Raw Ethernet

This is the most easy way but also the most limited one, your Linux Host will not be able to communicate with 6LBR and the WSN directly. As the name indicates, the 6LBR use directly the configured Ethernet interface to send and receive packets.

The configuration needed in your /etc/6lbr/6lbr.conf file is (if your Ethernet interface is eth0) :

RAW_ETH=1
BRIDGE=0
DEV_ETH=eth0

Bridge mode

This mode requires more configuration, but you will be able to communicate to the 6LBR form the Linux Host. In this mode, 6LBR will create a virtual Ethernet interface, usually tap0. You need to bridge it to your Ethernet interface in order to provide connectivity. The created Bridge interface will replace your Ethernet interface for all purposes.

The configuration needed in your /etc/6lbr/6lbr.conf file is (if your Ethernet interface is eth0) :

RAW_ETH=0
BRIDGE=1
CREATE_BRIDGE=0
DEV_ETH=eth0
DEV_BRIDGE=br0
DEV_TAP=tap0

You need also to create the Bridge interface, br0. In /etc/6lbr, we provides two examples of /etc/network/interfaces files to do so. For example, if you are using DHCP, the content of the file should be something like :

...

iface eth0 inet static
address 0.0.0.0

auto br0
iface br0 inet dhcp
    bridge_ports eth0
    bridge_stp off
    up echo 0 > /sys/devices/virtual/net/br0/bridge/multicast_snooping
    post-up ip link set br0 address `ip link show eth0 | grep ether | awk '{print $2}'`

...

As you see, the Ethernet interface is no longer configured, it has been replaced by br0.

It is possible to create the Bridge when 6LBR starts up, but this has as consequence that you will lose all your existing connections when the Ethernet interface join the bridge. If you really want this mode, you have to add to your 6lbr.conf file :

CREATE_BRIDGE=1

Routing mode

This mode is the most powerful, but also the most complex. Instead of creating a bridge to connect the tap0 interface and the et0 interface, you rely on the Linux Host stack to do routing between the two interfaces, either at IP level using actual routes or Ethernet level using ebtables. This is only useful when you have several interfaces or complex routing.

The configuration in 6lbr.conf is easy :

RAW_ETH=0
BRIDGE=0
DEV_ETH=eth0
DEV_TAP=tap0

More information

You can have a look at 6lbr.conf documentation for more information and configuration options.