subramanian wrote:I am able to connect to internet through pppoe in windows.
Best thing would probably be if you booted into Windows and systematically wrote down all the settings there, e.g. check with 'Control Panel' which device is configured how (e.g. IP adresses? Netmask? Dynamic IP or static IP? etc.) and then tried to replicate those setting on Linux. Also: Check your provider's forums, FAQ sections and tech support pages. At least here where I live all providers will give you the needed general tech information (= it works on any OS that speaks TCP/IP) in their tech sections so it might be worth to check it out. Even if they only give such infos for Windows or e.g. Mac OS (some providers here just do that) that would be sufficient to correctly apply those settings to Linux.
Because the little info you give is not nearly enough and without knowing how your setup is supposed to look like (e.g. by looking at the working Windows settings) any hints we give here would amount to wild guessing and I doubt that this woul get you anywhere unfortunately.
Can you please check your Windows settings and post them here? And check your provider's pages?