I am using a static wired connection. Everything was perfect.
But suddenly from few hours back I can't access any website. Dropbox, Ubuntu One also can't connect.
Ping request is also unsuccessful, but I can download through torrent. I am not trying torrent download and browsing at the same time. So, I think it's not an issue about torrent using all the bandwidth.
One important point is that this connection works perfectly on Windows on this same PC (My PC is dual-boot).
I have tried the way what izx has suggested (using "sudo sh -c 'echo nameserver 22.214.171.124 > /etc/resolv.conf'"), but I'm facing the same problem again. Now I can't even ping 126.96.36.199 and google.com. Though I can ping 188.8.131.52 (which is Google IP address)
I can't understand what's happening and why this is happening. I'm new in this website many rules and regulations is unknown to me. So, please don't be bothered for my mistakes. Looking forward for help from anyone.
Thanks to all.