Learning Debian GNU/Linux

PPP Client

The Linux PPP client lets your Linux system connect to the Internet via a PPP server, much the same way Dial-Up Networking lets your Microsoft Windows system do so. Behind the scenes, wvdial calls on the services of the PPP client to connect to a PPP server. However, it’s possible to use the Linux PPP client directly, without the aid of wvdial. Doing so gives you access to the many options provided by PPP, which can prove helpful if your networking needs are too sophisticated to be met by wvdial’s simple fire-and-forget mechanism. Even if you’re content with wvdial, you’ll benefit from understanding the PPP client. For example, you’ll find it much easier to troubleshoot PPP problems if you understand the functions performed by the PPP client on behalf of wvdial.

Specifying PPP Options

The Linux PPP client requires several configuration files. Rather than build these files manually, you can use pppconfig, a program that leads you through a dialog and then creates the proper configuration files based on your responses. Login as root, and issue the command:

pppconfig

Figure 11-1 shows pppconfig’s main menu, which the program displays whenever you start it. Notice that pppconfig lets you create a connection—the term by which it refers to a complete set of configuration parameters—but it does not let you edit an existing connection. To change a connection, you must edit the configuration files manually. It’s usually simpler to forego editing a connection, creating a new ...