I have a computer running Ubuntu 12.04 connected to our house wireless network and I would like to share this connection with a Lubuntu machine I'm setting up via direct ethernet. I have connected the two via ethernet, setting my wireless connected machine's wired connection to 'share with other machines'. I can ping from one machine to the other (when I turn off the firewall), but I can't access the internet on my Lubuntu machine, with a browser, or by pinging 126.96.36.199, www.google.etc.It just times-out.
As stated above, I repeat it here for emphasis, I have connected the two machines via ethernet by setting the IPv4 to 'Share to other computers' and by manually configuring the address on my second computer.
UPDATE: I have to add another test I just completed. I booted from a live USB and was able to connect my second computer to shared internet very easily. Following the same procedures on my installation it is still not working