1 This is the README file for ppp-2.4, a package which implements the
2 Point-to-Point Protocol (PPP) to provide Internet connections over
9 The Point-to-Point Protocol (PPP) provides a standard way to establish
10 a network connection over a serial link. At present, this package
11 supports IP and IPV6 and the protocols layered above them, such as TCP
12 and UDP. The Linux port of this package also has support for IPX.
14 This PPP implementation consists of two parts:
16 - Kernel code, which establishes a network interface and passes
17 packets between the serial port, the kernel networking code and the
18 PPP daemon (pppd). This code is implemented using STREAMS modules on
19 Solaris, and as a line discipline under Linux.
21 - The PPP daemon (pppd), which negotiates with the peer to establish
22 the link and sets up the ppp network interface. Pppd includes support
23 for authentication, so you can control which other systems may make a
24 PPP connection and what IP addresses they may use.
26 The platforms supported by this package are Linux and Solaris. I have
27 code for NeXTStep, FreeBSD, SunOS 4.x, SVR4, Tru64 (Digital Unix), AIX
28 and Ultrix but no active maintainers for these platforms. Code for
29 all of these except AIX is included in the ppp-2.3.11 release.
31 The kernel code for Linux is no longer distributed with this package,
32 since the relevant kernel code is in the official Linux kernel source
33 (and has been for many years) and is included in all reasonably modern
34 Linux distributions. The Linux kernel code supports using PPP over
35 things other than serial ports, such as PPP over Ethernet and PPP over
42 The file SETUP contains general information about setting up your
43 system for using PPP. There is also a README file for each supported
44 system, which contains more specific details for installing PPP on
45 that system. The supported systems, and the corresponding README
51 In each case you start by running the ./configure script. This works
52 out which operating system you are using and creates the appropriate
53 makefiles. You then run `make' to compile the user-level code, and
54 (as root) `make install' to install the user-level programs pppd, chat
57 N.B. Since 2.3.0, leaving the permitted IP addresses column of the
58 pap-secrets or chap-secrets file empty means that no addresses are
59 permitted. You need to put a "*" in that column to allow the peer to
60 use any IP address. (This only applies where the peer is
61 authenticating itself to you, of course.)
64 What's new in ppp-2.4.7.
65 ************************
67 * Fixed a potential security issue in parsing option files (CVE-2014-3158).
69 * There is a new "stop-bits" option, which takes an argument of 1 or 2,
70 indicating the number of stop bits to use for async serial ports.
75 What was new in ppp-2.4.6.
76 **************************
82 * Options files can now set and unset environment variables for
85 * The timeout for chat scripts can now be taken from an environment
88 * There is a new option, master_detach, which allows pppd to detach
89 from the controlling terminal when it is the multilink bundle master
90 but its own link has terminated, even if the nodetach option has
94 What was new in ppp-2.4.5.
95 **************************
97 * Under Linux, pppd can now operate in a mode where it doesn't request
98 the peer's IP address, as some peers refuse to supply an IP address.
99 Since Linux supports device routes as well as gateway routes, it's
100 possible to have no remote IP address assigned to the ppp interface
101 and still route traffic over it.
103 * Pppd now works better with 3G modems that do strange things such as
104 sending IPCP Configure-Naks with the same values over and over again.
106 * The PPP over L2TP plugin is included, which works with the pppol2tp
107 PPP channel code in the Linux kernel. This allows pppd to be used
108 to set up tunnels using the Layer 2 Tunneling Protocol.
110 * A new 'enable-session' option has been added, which enables session
111 accounting via PAM or wtwp/wtmpx, as appropriate. See the pppd man
114 * Several bugs have been fixed.
117 What was new in ppp-2.4.4.
118 **************************
120 * Pppd will now run /etc/ppp/ip-pre-up, if it exists, after creating
121 the ppp interface and configuring its IP addresses but before
122 bringing it up. This can be used, for example, for adding firewall
123 rules for the interface.
125 * Lots of bugs fixed, particularly in the area of demand-dialled and
126 persistent connections.
128 * The rp-pppoe plugin now accepts any interface name (that isn't an
129 existing pppd option name) without putting "nic-" on the front of
130 it, not just eth*, nas*, tap* and br*.
133 What was new in ppp-2.4.3.
134 **************************
136 * The configure script now accepts --prefix and --sysconfdir options.
137 These default to /usr/local and /etc. If you want pppd put in
138 /usr/sbin as before, use ./configure --prefix=/usr.
140 * Doing `make install' no longer puts example configuration files in
141 /etc/ppp. Use `make install-etcppp' if you want that.
143 * The code has been updated to work with version 0.8.3 of libpcap.
144 Unfortunately the libpcap maintainers removed support for the
145 "inbound" and "outbound" keywords on PPP links, meaning that if you
146 link pppd with libpcap-0.8.3, you can't use those keywords in the
147 active-filter and pass-filter expressions. The support has been
148 reinstated in the CVS version and should be in future libpcap
149 releases. If you need the in/outbound keywords, use a later release
150 than 0.8.3, or get the CVS version from http://www.tcpdump.org.
152 * There is a new option, child-timeout, which sets the length of time
153 that pppd will wait for child processes (such as the command
154 specified with the pty option) to exit before exiting itself. It
155 defaults to 5 seconds. After the timeout, pppd will send a SIGTERM
156 to any remaining child processes and exit. A value of 0 means no
159 * Various bugs have been fixed, including some CBCP packet parsing
160 bugs that could lead to the peer being able to crash pppd if CBCP
163 * Various fixes and enhancements to the radius and rp-pppoe plugins
166 * There is a new winbind plugin, from Andrew Bartlet of the Samba
167 team, which provides the ability to authenticate the peer against an
168 NT domain controller using MS-CHAP or MS-CHAPV2.
170 * There is a new pppoatm plugin, by various authors, sent in by David
173 * The multilink code has been substantially reworked. The first pppd
174 for a bundle still controls the ppp interface, but it doesn't exit
175 until all the links in the bundle have terminated. If the first
176 pppd is signalled to exit, it signals all the other pppds
177 controlling links in the bundle.
179 * The TDB code has been updated to the latest version. This should
180 eliminate the problem that some people have seen where the database
181 file (/var/run/pppd.tdb) keeps on growing. Unfortunately, however,
182 the new code uses an incompatible database format. For this reason,
183 pppd now uses /var/run/pppd2.tdb as the database filename.
186 What was new in ppp-2.4.2.
187 **************************
189 * The CHAP code has been rewritten. Pppd now has support for MS-CHAP
190 V1 and V2 authentication, both as server and client. The new CHAP
191 code is cleaner than the old code and avoids some copyright problems
192 that existed in the old code.
194 * MPPE (Microsoft Point-to-Point Encryption) support has been added,
195 although the current implementation shouldn't be considered
196 completely secure. (There is no assurance that the current code
197 won't ever transmit an unencrypted packet.)
199 * James Carlson's implementation of the Extensible Authentication
200 Protocol (EAP) has been added.
202 * Support for the Encryption Control Protocol (ECP) has been added.
204 * Some new plug-ins have been included:
205 - A plug-in for kernel-mode PPPoE (PPP over Ethernet)
206 - A plug-in for supplying the PAP password over a pipe from another
208 - A plug-in for authenticating using a Radius server.
210 * Updates and bug-fixes for the Solaris port.
212 * The CBCP (Call Back Control Protocol) code has been updated. There
213 are new options `remotenumber' and `allow-number'.
215 * Extra hooks for plugins to use have been added.
217 * There is now a `maxoctets' option, which causes pppd to terminate
218 the link once the number of bytes passed on the link exceeds a given
221 * There are now options to control whether pppd can use the IPCP
222 IP-Address and IP-Addresses options: `ipcp-no-address' and
225 * Fixed several bugs, including potential buffer overflows in chat.
228 What was new in ppp-2.4.1.
229 **************************
231 * Pppd can now print out the set of options that are in effect. The
232 new `dump' option causes pppd to print out the option values after
233 option parsing is complete. The `dryrun' option causes pppd to
234 print the options and then exit.
236 * The option parsing code has been fixed so that options in the
237 per-tty options file are parsed correctly, and don't override values
238 from the command line in most cases.
240 * The plugin option now looks in /usr/lib/pppd/<pppd-version> (for
241 example, /usr/lib/pppd/2.4.1b1) for shared objects for plugins if
242 there is no slash in the plugin name.
244 * When loading a plugin, pppd will now check the version of pppd for
245 which the plugin was compiled, and refuse to load it if it is
246 different to pppd's version string. To enable this, the plugin
247 source needs to #include "pppd.h" and have a line saying:
248 char pppd_version[] = VERSION;
250 * There is a bug in zlib, discovered by James Carlson, which can cause
251 kernel memory corruption if Deflate is used with the lowest setting,
252 8. As a workaround pppd will now insist on using at least 9.
254 * Pppd should compile on Solaris and SunOS again.
256 * Pppd should now set the MTU correctly on demand-dialled interfaces.
259 What was new in ppp-2.4.0.
260 **************************
262 * Multilink: this package now allows you to combine multiple serial
263 links into one logical link or `bundle', for increased bandwidth and
264 reduced latency. This is currently only supported under the
265 2.4.x and later Linux kernels.
267 * All the pppd processes running on a system now write information
268 into a common database. I used the `tdb' code from samba for this.
270 * New hooks have been added.
272 For a list of the changes made during the 2.3 series releases of this
273 package, see the Changes-2.3 file.
279 This package supports two packet compression methods: Deflate and
280 BSD-Compress. Other compression methods which are in common use
281 include Predictor, LZS, and MPPC. These methods are not supported for
282 two reasons - they are patent-encumbered, and they cause some packets
283 to expand slightly, which pppd doesn't currently allow for.
284 BSD-Compress and Deflate (which uses the same algorithm as gzip) don't
291 The comp.protocols.ppp newsgroup is a useful place to get help if you
292 have trouble getting your ppp connections to work. Please do not send
293 me questions of the form "please help me get connected to my ISP" -
294 I'm sorry, but I simply do not have the time to answer all the
295 questions like this that I get.
297 If you find bugs in this package, please report them to the maintainer
298 for the port for the operating system you are using:
300 Linux Paul Mackerras <paulus@samba.org>
301 Solaris James Carlson <carlson@workingcode.com>
307 All of the code can be freely used and redistributed. The individual
308 source files each have their own copyright and permission notice.
309 Pppd, pppstats and pppdump are under BSD-style notices. Some of the
310 pppd plugins are GPL'd. Chat is public domain.
316 The primary site for releases of this software is:
318 ftp://ftp.samba.org/pub/ppp/