ADSL and Cable under Linux

For ADSL in Israel, PPTP or PPPoE is used for the connection.
Both are supported under Linux.
PPPoE is supported natively by most modern distributions, and usually the distribution has a wizard which will help setting up the link.
The relevant package is called rp-pppoe and includes a script "adsl-setup" to configure your connection and "adsl-start" to initiate a connection after setup.
The PPTP protocol support is a bit more problematic to set up, but yet possible, and works well.
A HOWTO about connecting to ADSL in Israel using PPTP (written by Dr. Daniel Arbel and Muli Ben-Yehuda) can be found here: http://www.mulix.org/adsl.html
The cable TV Internet access providers sometime provide a direct Ethernet connection, using DHCP to assign IP address and to inform the computer about the network details it need to know, without any need for a tunnel.

4.2.1. ADSL and Cable under Linux