ppp/README

This is the README file for ppp-2.2, a package which implements the
Point-to-Point Protocol (PPP) to provide Internet connections over
serial lines.


Introduction.
*************

The Point-to-Point Protocol (PPP) provides a standard way to transmit
datagrams over a serial link, as well as a standard way for the
machines at either end of the link (the `peers') to negotiate various
optional characteristics of the link.  Using PPP, a serial link can be
used to transmit Internet Protocol (IP) datagrams, allowing TCP/IP
connections between the peers.  PPP is defined in several RFC (Request
For Comments) documents, in particular RFCs 1661, 1662, 1332 and 1334.
Other RFCs describe standard ways to transmit datagrams from other
network protocols (e.g., DECnet, OSI, Appletalk), but this package
only supports IP.

This software consists of two parts:

- Kernel code, which establishes a network interface and passes
packets between the serial port, the kernel networking code and the
PPP daemon (pppd).  This code is implemented using STREAMS modules on
SunOS 4.x, AIX 4.1 and OSF/1, and as a line discipline under Ultrix,
NextStep, NetBSD, FreeBSD, and Linux.

- The PPP daemon (pppd), which negotiates with the peer to establish
the link and sets up the ppp network interface.  Pppd includes support
for authentication, so you can control which other systems may make a
PPP connection and what IP addresses they may use.


Installation.
*************

The file SETUP contains general information about setting up your
system for using PPP.  There is also a README file for each supported
system, which contains more specific details for installing PPP on
that system.  The supported systems, and the corresponding README
files, are:

	SunOS 4.x			README.sun
	NetBSD, FreeBSD			README.bsd
	Ultrix 4.x			README.ultrix
	Linux				README.linux
	OSF/1				README.osf
	AIX 4.x				README.aix4
	NeXTStep			README.next
	Solaris 2			README.svr4

In each case you start by running the ./configure script.  This works
out which operating system you are using and creates symbolic links to
the appropriate makefiles.  You then run `make' to compile the
user-level code, and (as root) `make install' to install the
user-level programs pppd, chat and pppstats.

The procedures for installing the kernel code vary from system to
system.  On some systems, the kernel code can be loaded into a running
kernel using a `modload' facility.  On others, the kernel image has to
be recompiled and the system rebooted.  See the README.* files for
details.


What is new in ppp-2.2.
***********************

* More systems are now supported:

  AIX 4, thanks to Charlie Wick (cwick@quaver.urbana.mcd.mot.com)
  OSF/1 on DEC Alpha, thanks to Steve Tate (srt@zaphod.csci.unt.edu)
  NextStep 3.2 and 3.3, thanks to Philip-Andrew Prindeville
	(philipp@res.enst.fr) and Steve Perkins (perkins@cps.msu.edu)
  Solaris 2

in addition to NetBSD 1.0, SunOS 4.x, Ultrix 4.x, FreeBSD 2.0, and
Linux.

* Packet compression has been implemented.  This version implements
CCP (Compression Control Protocol) and the BSD-Compress compression
scheme according to the current draft RFCs.  This means that incoming
and outgoing packets can be compressed with the LZW scheme (same as
the `compress' command) using a code size of up to 15 bits.

* Some bug fixes to the LCP protocol code.  In particular, pppd now
correctly replies with a Configure-NAK (instead of a Configure-Reject)
if the peer asks for CHAP and pppd is willing to do PAP but not CHAP.

* The ip-up and ip-down scripts are now run with the real user ID set
to root, and with an empty environment.  Clearing the environment
fixes a security hole.

* The kernel code on NetBSD, FreeBSD, NextStep and Ultrix has been
restructured to make it easier to implement PPP over devices other
than asynchronous tty ports (for example, synchronous serial ports).

* pppd now looks at the list of interfaces in the system to determine
what the netmask should be.  In most cases, this should eliminate the
need to use the `netmask' option.

* There is a new `papcrypt' option to pppd, which specifies that
secrets in /etc/ppp/pap-secrets used for authenticating the peer are
encrypted, so pppd always encrypts the peer's password before
comparing it with the secret from /etc/ppp/pap-secrets.  This gives
better security.


Patents.
********

The BSD-Compress algorithm used for packet compression is the same as
that used in the Unix "compress" command.  It is apparently covered by
U.S. patents 4,814,746 (owned by IBM) and 4,558,302 (owned by Unisys),
and corresponding patents in various other countries (but not
Australia).  If this is of concern, you can build the package without
including BSD-Compress.  To do this, edit net/ppp-comp.h to change the
definition of DO_BSD_COMPRESS to 0.  The bsd-comp.c files are then no
longer needed, so the references to bsd-comp.o may optionally be
removed from the Makefiles.


Contacts.
*********

Bugs in the the SunOS, NetBSD and Ultrix ports and bugs in pppd, chat
or pppstats should be reported to:

	paulus@cs.anu.edu.au
	Paul Mackerras
	Dept. of Computer Science
	Australian National University
	Canberra  ACT  0200
	AUSTRALIA

Bugs in other ports should be reported to the maintainer for that port
(see the appropriate README.* file) or to the above.

Thanks to:

	Brad Parker  (brad@fcr.com)
	Greg Christy (gmc@quotron.com)
	Drew D. Perkins (ddp@andrew.cmu.edu)
	Rick Adams (rick@seismo.ARPA)
	Chris Torek (chris@mimsy.umd.edu, umcp-cs!chris).


Copyrights:

Most of the code can be freely used and redistributed.  The STREAMS
code for SunOS 4.x, OSF/1 and AIX 4 is under a more restrictive
copyright:

	This code is Copyright (C) 1989, 1990 By Brad K. Clements, 
	All Rights Reserved.

	You may use this code for your personal use, to provide a non-profit
	service to others, or to use as a test platform for a commercial
	implementation.

	You may NOT use this code in a commercial product, nor to provide a 
	commercial service, nor may you sell this code without express
	written permission of the author.

	Otherwise, Enjoy!

This copyright applies to (parts of) the following files:

	sunos/ppp_async.c
	sunos/ppp_if.c
	aix4/ppp_async.c
	aix4/ppp_if.c
	net/ppp_str.h
	pppd/sys-str.c
	pppd/sys-osf.c
	pppd/sys-aix4.c