I just did a fresh install of 11.10. But can't connect to the internet with the same set-up I used in 11.04. I used a DSL connection there, with only setting the username and password, it worked fine. But now, each time I make an attempt to connect, it shows "connection established" pop-up but in half a second, it again disconnects. I searched the web and found a work-around which says to set IPv6 to ignored and killall dnsmasq but nothing worked.
Perhaps this trick is not for me, as I am new, did not realize. However I just realized that more people are also having the issue. Now, what do I need to do to get access to internet? In 11.04 where i could connect, I was using gnome desktop. Now its Unity 3D.
I don't know what a router is. My pc is connected from the back panel of the CPU casing trough a rectangular port which glows when power is on. Then this line is connected to a black box in my house. This box says it's a "5-Port 10/100Mbps Nway Switch." From this box, two more windows pc are connected and the are fine. And another line came from outside and is connected to this box. In my wire, I checked connecting a windows pc and it worked. This black rectangular box requires AC power.