Ubuntu – Share Internet Connection via Ethernet connected Router over the LAN

Here's how I did it:

Equipment:

• Ubuntu 11.04 Desktop on 1st Gen. eeePC

• Linksys WRT120N Wireless N Router

• Huawei E620 USB Broadband Modem

• Ethernet cable

Hardware Setup:

• Huawei plugged into eeePC

• Ethernet cable plugged into Ethernet port

• other end of Ethernet cable plugged into the Internet port of The Linksys

Ubuntu Setup:

1. connect the Huawei to the Internet
2. disconnect the wired connection (Auto Eth0) in network tray icon
3. create new wired connection (Edit Connections... > Add, enter a name) and select Shared To Other Computers from IPv4 settings tab.
4. connect to this new wired connection
5. note down the settings for this connection under Connection Information, and the DNS servers for the Huawei connection

Linksys Setup:

1. connect a computer on the receiving side to the Linksys (wired or wireless)
2. open a browser in this computer, navigate to Linksys (192.168.1.1 is default, user and password should be both admin)
3. Change Internet Connection Type to Static IP
4. Under Internet IP Address I put the number that came after the eeePC's IP address for this connection (again, not the IP for the Huawei connection), this was just a guess as I'm pretty clueless about how this works. So, my Ubuntu machine had an IP of 10.42.43.1, and I gave the Linksys 10.42.43.2
5. Subnet Mask should be same as the eeePC, 255.255.255.0
6. Default Gateway should be the eeePC's IP address, 10.42.43.1 in my case.
7. DNS 1 (etc.) should be the same as the Primary DNS (etc.) used by the eeePC in the Huawei connection.
8. Click Save Settings.

And now all machines on my LAN can connect to the eeePC's Internet via the linksys router. All is well.

1. Click the network icon
2. Select "Create wireless network"
3. Choose a name, encryption type and password
4. Click create
5. Make sure you're connected to the internet.