Using the Ethernet Expansion

The Ethernet Expansion is a piece of hardware that gives your Omega the ability to establish an Ethernet connection with other devices. With this Expansion, you can use your Omega as a router, an Ethernet bridge, and more.

You can learn more about the technical specifications of the Ethernet Expansion in our Ethernet Expansion hardware overview

Connecting to a Network through Ethernet

The Omega can use the Ethernet Expansion to join a network via a wired connection, much like a desktop computer. This type of connection requires some minor configuration changes, so we’re going to go through how to properly set up your Omega to use an Ethernet Expansion.

Step 1: Enable eth0

The Omega’s Ethernet interface is named eth0. In order to use the Ethernet Expansion, you will need to make sure this is enabled. To do this, you will need to open up the /etc/config/network file, find the block that looks something like the following:

config interface 'wan'
   option ifname 'eth0'
   option proto 'dhcp'   

If that block does not exist, you’ll need to add it in.

This will tell the Omega to turn on the eth0 interface and we will also be referring to this network as wan.

Once you have saved and closed the file, run the following command to restart the network service to reload the new configuration:

/etc/init.d/network restart

Step 2: Enabling Packet Routing

Next, you will need to configure the Omega to route packets from the Ethernet interface (eth0) to your WiFi interface (wlan0). To do this, you will be editing the /etc/config/firewall file:

Find the block that looks something like the following:

config zone
    option name         wan
    list   network      'wwan'
    option input        ACCEPT
    option output       ACCEPT
    option forward      ACCEPT
    option masq     1
    option mtu_fix      1

and add the following line:

list   network      'wan'

What you will end up with is something like the following:

config zone
    option name         wan
    list   network      'wwan'
    list   network      'wan'
    option input        ACCEPT
    option output       ACCEPT
    option forward      ACCEPT
    option masq         1
    option mtu_fix      1

What this tells the Omega to do is to add the wan network (which we defined in the /etc/config/network file) to a firewall zone called wan. This zone has already been setup to route packets to another firewall zone called lan, which contains the br-wlan interface.

Once you have saved and closed the file, run the following command to restart the firewall with the updated configuration:

/etc/init.d/firewall restart

Your Ethernet Expansion is now ready to supply an internet connection to your Omega. Simply plug an Ethernet cord into an Ethernet port on a modem or a router, and connect it to your Ethernet Expansion.

Going Further with the Ethernet Expansion

If you don’t have a router and need to supply a wireless network and internet connectivity to devices, the Ethernet Expansion can transform the Omega into a very effective router. For more on that you can read our tutorial on transforming your Omega into a router

You can use the Ethernet Expansion and the Omega to provide a wired connection to a laptop or a computer. This is known as an Ethernet Bridge, and you can learn more about it in our tutorial on creating an Ethernet Bridge using the Omega