Linux PPP HOWTO

Robert Hart,

hartr@interweft.com.au

v3.0, 31 March 1997

This document shows how to connect your Linux PC to a PPP server, how to use PPP to link two LANs together and provides one method of setting up your Linux computer as a PPP server.The document also provides help in debugging non-functional PPP connections.

Copyright

This document is distributed under the terms of the GPL (GNU Public License).

Distribution

This document will be posted to comp.os.linux.answers as new versions of the document are produced. It is also available in HTML format at:-

• Linux Howto Index
• PPP-HOWTO

Other formats (SGML, ASCII, postscript, DVI) are available from Howtos - other formats.

As sunsite.unc.edu carries a very heavy load, please use an appropriate mirror site close to you.

Acknowledgements

A growing number of people have provided me with assistance in preparing this document. Special thanks go to Al Longyear for the guidance on PPP itself (if there are mistakes here, they are mine not his), Greg Hankins (maintainer of the Linux Howto system)and Debi Tackett (of MaximumAccess.com) for many helpful suggestions on style, content order, logic and clarity of explanations.

Finally, to the many people who have contacted me by email offering comments - my thanks. As with all HOWTO authors, the satisfaction of helping is all the payment we receive and it is enough. By writing this HOWTO I am repaying in a small way the debt I - and all other Linux users - owe to the people who write and maintain our OS of choice.

1. Introduction

• 1.1 Clients and Servers
• 1.2 Differences between Linux distributions
• 1.3 Distribution specific PPP configuration tools

2. IP Numbers

3. Aims of this Document

• 3.1 Setting up a PPP Client
• 3.2 Linking two LANs or a LAN to the Internet using PPP
• 3.3 Setting up a PPP server
• 3.4 Using PPP over a direct null modem connection
• 3.5 This document at present does NOT cover...

4. Software versions covered

5. Other Useful/Important Documents

• 5.1 Useful Linux Mailing Lists

6. Overview of what has to be done to get PPP working as a client

• 6.1 Obtaining/Installing the software
• 6.2 Compiling PPP support into the kernel
• 6.3 Obtaining information from your ISP
• 6.4 Configuring your modem and serial port
• 6.5 Setting up Name to Address Resolution (DNS)
• 6.6 PPP and root Privileges
• 6.7 Checking your distribution PPP Files and setting up the PPP Options
• 6.8 If your PPP server uses PAP (Password Authentication Protocol)
• 6.9 Connecting to the PPP server by hand
• 6.10 Automating your PPP Connection
• 6.11 Shutting down the link
• 6.12 If you have problems
• 6.13 After the link comes up
• 6.14 Problems with standard IP services on a Dynamic IP number PPP link

7. Configuring your Linux Kernel

• 7.1 Installing the Linux Kernel source
• 7.2 Knowing your hardware
• 7.3 Kernel compilation - the Linux 1.2.13 kernel
• 7.4 Kernel compilation - the Linux 1.3.x and 2.0.x kernels
• 7.5 Note on PPP-2.2 and
• /proc/net/dev
• 7.6 General kernel config considerations for PPP