How to connect to internet through an ADSL ethernet modem with username and password (PPPoE)

Connecting to internet with a flat connection is really as easy as pluggin in the ethernet cable.

Little more complex is when you have to log in since you pay per time your internet connection.
In order to set your username and password call pppoeconf

sudo pppoeconf

select the ethernet port you have your cable connected to (if you have only one ethernet port that should be eth0)
Now write down username and password, not caring for advanced configuration options.
At one point you can choose whether initiate the connection at login or not, choose what you think best fits your needs.

In order to connect to internet type

pon dsl-provider

to disconnect

pof