As already mentioned, there are many ways to do this. What I present here is the way I do it, (using a Cyclades multi-port serial card), and a rotary dial in set of telephone lines.
If you don't like the method I present here, please feel free to go your own way. I would however, be pleased to include additional methods in future versions of the HOWTO. So, please send me your comments and methods!
Please note, this section only concerns setting up Linux as a PPP server. I do not (ever) intend to include information on setting up special terminal servers and such.
Also, I have yet to experiment with shadow passwords (but will be doing so sometime). Information currently presented does NOT therefore include any bells and whistles that are required by the shadow suite.
All the earlier comments regarding kernel compilation and kernel versions versus pppd versions apply. This section assumes that you have read the earlier sections of this document!
For a PPP server, you MUST include IP forwarding in your kernel. You may also wish to include other capabilities (such as IP fire walls, accounting etc etc).
If you are using a multi-port serial card, then you must obviously include the necessary drivers in your kernel too!