Hello
If your PPPoE connection is configured (i.e dsl bridge is
created) then you can use KInternet for connecting to internet. Don't
keep your IP Address static. make its setting DHCP, since your modem
assign it a ip address when it get connected. So a LAN is created and
modem (which is actually working as router) work as gateway.

Any problem feel free to ask. I have connected my laptop to Internet
at many of my friends BSNL broadband connection, using OpenSuse. It
always work.