hey nithin, you are having that problem cause the pppoe cant figure out which service you are trying to log in on... this will fix it..!
you will need to edit a perticular file located at here
/etc/ppp/peers/dsl-provider
to do so, go to konsol and type
#gksu gedit /etc/ppp/peers/dsl-provider
in that file you will see a line something like this
plugin rp-pppoe.so eth0
you will need to insert this into the line before eth0
rp_pppoe_service
replace the "" with your net-service name. (the dialer you use in
windows should have that name)
so the line should look like this
plugin rp-pppoe.so rp_pppoe_service eth0
save and close the file. now
pon dsl-provider command should work like a charm.