The K Desktop Environment

2.4. Preparing Your Linux System for a PPP Connection

In order for kppp/pppd to work your kernel must have ppp support compiled in. If this is not the case get yourself the latest version of pppd from any of the popular Linux archives and recompile your kernel with ppp support enabled. Don't fret since this sounds scarier than it actually is. Don't forget to install pppd afterwards. If unsure whether you have a kernel with ppp support issue dmesg at the command prompt and look for something like this:

 PPP: version 2.3.0 (demand dialling)
 TCP compression code copyright 1989 Regents of the University of California
 PPP Dynamic channel allocation code copyright 1995 Caldera, Inc.
 PPP line discipline registered

Update: kppp since version 1.5.32 tries to find out itself if the kernel supports PPP. If not, you will be notified on start of kppp. This feature is not well tested, so you should not rely on it for now.

There were changes in the kernel PPP from Linux version 1.2.x to 2.0.x which forced the programming of a new pppd daemon. In most distributions, the pppd daemon can be found in /usr/sbin. For kernel versions 1.2.x, the correct version of the pppd daemon is 2.1; for kernel versions 2.0.x, the correct version is 2.2. or newer; for kernel versions 2.1.x and 2.2.x you need pppd version 2.3. If you don't know what version of the pppd daemon your system has, you can type:

 % pppd --version

None of the pppd daemons actually have a --version option, but putting the option in will cause the pppd daemon to error out from a unrecognised option and print out a list of options, which includes the version of the pppd daemon.