source: rtems/cpukit/pppd/pppd.8 @ 9d770ab5

4.104.114.84.95
Last change on this file since 9d770ab5 was 2f1b930, checked in by Joel Sherrill <joel.sherrill@…>, on 08/16/01 at 20:42:09

2001-08-16 Mike Siers <mikes@…>

  • Update of PPPD to 2.3.11 from 2.3.5 and addition of an example application. Mike's notes on the modifications:
    • renamed error() function because of namespace problems
    • removed calls to the exit() funciton
    • removed extra files from the pppd source directory
    • defined pppd task constant values in rtemspppd.h
    • modifyied example code to get actual tick per second value
    • placed the pppd 2.3.11 man page file (pppd.8) into the pppd directory
  • pppd/cbcp.c, pppd/cbcp.h, pppd/main.c, pppd/ppp_tty.c, pppd/pppmain.c, pppd/rtems-ppp.c, pppd/rtems-ppp.c: Deleted.
  • pppd/pppd.8, pppd/rtemsmain.c, pppd/rtemspppd.c, pppd/rtemspppd.h, pppd/sys-rtems.c, pppd/utils.c, pppd/example/Makefile, pppd/example/README, pppd/example/init.c, pppd/example/netconfig.h, pppd/example/ppp.conf, pppd/example/pppdapp.c, pppd/example/system.h: New files.
  • modem/ppp_tty.c, net/if_ppp.h, pppd/Makefile.am, pppd/README, pppd/STATUS, pppd/auth.c, pppd/ccp.c, pppd/ccp.h, pppd/chap.c, pppd/chap.h, pppd/chap_ms.c, pppd/chap_ms.h, pppd/chat.c, pppd/demand.c, pppd/fsm.c, pppd/fsm.h, pppd/ipcp.c, pppd/ipcp.h, pppd/ipxcp.c, pppd/ipxcp.h, pppd/lcp.c, pppd/lcp.h, pppd/magic.c, pppd/magic.h, pppd/options.c, pppd/patchlevel.h, pppd/pathnames.h, pppd/pppd.h, pppd/upap.c, pppd/upap.h: Modified.
  • Property mode set to 100644
File size: 61.4 KB
Line 
1.\" manual page [] for pppd 2.3
2.\" $Id$
3.\" SH section heading
4.\" SS subsection heading
5.\" LP paragraph
6.\" IP indented paragraph
7.\" TP hanging label
8.TH PPPD 8
9.SH NAME
10pppd \- Point to Point Protocol daemon
11.SH SYNOPSIS
12.B pppd
13[
14.I tty_name
15] [
16.I speed
17] [
18.I options
19]
20.SH DESCRIPTION
21.LP
22The Point-to-Point Protocol (PPP) provides a method for transmitting
23datagrams over serial point-to-point links.  PPP
24is composed of three parts: a method for encapsulating datagrams over
25serial links, an extensible Link Control Protocol (LCP), and
26a family of Network Control Protocols (NCP) for establishing
27and configuring different network-layer protocols.
28.LP
29The encapsulation scheme is provided by driver code in the kernel.
30Pppd provides the basic LCP, authentication support, and an NCP for
31establishing and configuring the Internet Protocol (IP) (called the IP
32Control Protocol, IPCP).
33.SH FREQUENTLY USED OPTIONS
34.TP
35.I <tty_name>
36Communicate over the named device.  The string "/dev/" is prepended if
37necessary.  If no device name is given, or if the name of the terminal
38connected to the standard input is given, pppd will use that terminal,
39and will not fork to put itself in the background.  A value for this
40option from a privileged source cannot be overridden by a
41non-privileged user.
42.TP
43.I <speed>
44Set the baud rate to <speed> (a decimal number).  On systems such as
454.4BSD and NetBSD, any speed can be specified.  Other systems
46(e.g. SunOS) allow only a limited set of speeds.
47.TP
48.B asyncmap \fI<map>
49Set the async character map to <map>.  This map describes which
50control characters cannot be successfully received over the serial
51line.  Pppd will ask the peer to send these characters as a 2-byte
52escape sequence.  The argument is a 32 bit hex number with each bit
53representing a character to escape.  Bit 0 (00000001) represents the
54character 0x00; bit 31 (80000000) represents the character 0x1f or ^_.
55If multiple \fIasyncmap\fR options are given, the values are ORed
56together.  If no \fIasyncmap\fR option is given, no async character
57map will be negotiated for the receive direction; the peer should then
58escape \fIall\fR control characters.  To escape transmitted
59characters, use the \fIescape\fR option.
60.TP
61.B auth
62Require the peer to authenticate itself before allowing network
63packets to be sent or received.  This option is the default if the
64system has a default route.  If neither this option nor the
65\fInoauth\fR option is specified, pppd will only allow the peer to use
66IP addresses to which the system does not already have a route.
67.TP
68.B call \fIname
69Read options from the file /etc/ppp/peers/\fIname\fR.  This file may
70contain privileged options, such as \fInoauth\fR, even if pppd
71is not being run by root.  The \fIname\fR string may not begin with /
72or include .. as a pathname component.  The format of the options file
73is described below.
74.TP
75.B connect \fIscript
76Use the executable or shell command specified by \fIscript\fR to set
77up the serial line.  This script would typically use the chat(8)
78program to dial the modem and start the remote ppp session.  A value
79for this option from a privileged source cannot be overridden by a
80non-privileged user.
81.TP
82.B crtscts
83Use hardware flow control (i.e. RTS/CTS) to control the flow of
84data on the serial port.  If neither the \fIcrtscts\fR, the
85\fInocrtscts\fR, the \fIcdtrcts\fR nor the \fInocdtrcts\fR option
86is given, the hardware flow control setting for the serial port is
87left unchanged.
88Some serial ports (such as Macintosh serial ports) lack a true
89RTS output. Such serial ports use this mode to implement
90unidirectional flow control. The serial port will
91suspend transmission when requested by the modem (via CTS)
92but will be unable to request the modem stop sending to the
93computer. This mode retains the ability to use DTR as
94a modem control line.
95.TP
96.B defaultroute
97Add a default route to the system routing tables, using the peer as
98the gateway, when IPCP negotiation is successfully completed.
99This entry is removed when the PPP connection is broken.  This option
100is privileged if the \fInodefaultroute\fR option has been specified.
101.TP
102.B disconnect \fIscript
103Run the executable or shell command specified by \fIscript\fR after
104pppd has terminated the link.  This script could, for example, issue
105commands to the modem to cause it to hang up if hardware modem control
106signals were not available.  The disconnect script is not run if the
107modem has already hung up.  A value for this option from a privileged
108source cannot be overridden by a non-privileged user.
109.TP
110.B escape \fIxx,yy,...
111Specifies that certain characters should be escaped on transmission
112(regardless of whether the peer requests them to be escaped with its
113async control character map).  The characters to be escaped are
114specified as a list of hex numbers separated by commas.  Note that
115almost any character can be specified for the \fIescape\fR option,
116unlike the \fIasyncmap\fR option which only allows control characters
117to be specified.  The characters which may not be escaped are those
118with hex values 0x20 - 0x3f or 0x5e.
119.TP
120.B file \fIname
121Read options from file \fIname\fR (the format is described below).
122The file must be readable by the user who has invoked pppd.
123.TP
124.B init \fIscript
125Run the executable or shell command specified by \fIscript\fR to
126initialize the serial line.  This script would typically use the
127chat(8) program to configure the modem to enable auto answer.  A value
128for this option from a privileged source cannot be overridden by a
129non-privileged user.
130.TP
131.B lock
132Specifies that pppd should create a UUCP-style lock file for the
133serial device to ensure exclusive access to the device.
134.TP
135.B mru \fIn
136Set the MRU [Maximum Receive Unit] value to \fIn\fR. Pppd
137will ask the peer to send packets of no more than \fIn\fR bytes.  The
138minimum MRU value is 128.  The default MRU value is 1500.  A value of
139296 is recommended for slow links (40 bytes for TCP/IP header + 256
140bytes of data).  (Note that for IPv6 MRU must be at least 1280)
141.TP
142.B mtu \fIn
143Set the MTU [Maximum Transmit Unit] value to \fIn\fR.  Unless the
144peer requests a smaller value via MRU negotiation, pppd will
145request that the kernel networking code send data packets of no more
146than \fIn\fR bytes through the PPP network interface.  (Note that for
147IPv6 MTU must be at least 1280)
148.TP
149.B passive
150Enables the "passive" option in the LCP.  With this option, pppd will
151attempt to initiate a connection; if no reply is received from the
152peer, pppd will then just wait passively for a valid LCP packet from
153the peer, instead of exiting, as it would without this option.
154.SH OPTIONS
155.TP
156.I <local_IP_address>\fB:\fI<remote_IP_address>
157Set the local and/or remote interface IP addresses.  Either one may be
158omitted.  The IP addresses can be specified with a host name or in
159decimal dot notation (e.g. 150.234.56.78).  The default local
160address is the (first) IP address of the system (unless the
161\fInoipdefault\fR
162option is given).  The remote address will be obtained from the peer
163if not specified in any option.  Thus, in simple cases, this option is
164not required.  If a local and/or remote IP address is specified with
165this option, pppd
166will not accept a different value from the peer in the IPCP
167negotiation, unless the \fIipcp-accept-local\fR and/or
168\fIipcp-accept-remote\fR options are given, respectively.
169.TP
170.B ipv6 \fI<local_interface_identifier>\fR,\fI<remote_interface_identifier>
171Set the local and/or remote 64-bit interface identifier. Either one may be
172omitted. The identifier must be specified in standard ascii notation of
173IPv6 addresses (e.g. ::dead:beef). If the
174\fIipv6cp-use-ipaddr\fR
175option is given, the local identifier is the local IPv4 address (see above).
176On systems which supports a unique persistent id, such as EUI-48 derived
177from the Ethernet MAC address, \fIipv6cp-use-persistent\fR option can be
178used to replace the \fIipv6 <local>,<remote>\fR option. Otherwise the
179identifier is randomized.
180.TP
181.B active-filter \fIfilter-expression
182Specifies a packet filter to be applied to data packets to determine
183which packets are to be regarded as link activity, and therefore reset
184the idle timer, or cause the link to be brought up in demand-dialling
185mode.  This option is useful in conjunction with the
186\fBidle\fR option if there are packets being sent or received
187regularly over the link (for example, routing information packets)
188which would otherwise prevent the link from ever appearing to be idle.
189The \fIfilter-expression\fR syntax is as described for tcpdump(1),
190except that qualifiers which are inappropriate for a PPP link, such as
191\fBether\fR and \fBarp\fR, are not permitted.  Generally the filter
192expression should be enclosed in single-quotes to prevent whitespace
193in the expression from being interpreted by the shell. This option
194is currently only available under NetBSD, and then only
195if both the kernel and pppd were compiled with PPP_FILTER defined.
196.TP
197.B allow-ip \fIaddress(es)
198Allow peers to use the given IP address or subnet without
199authenticating themselves.  The parameter is parsed as for each
200element of the list of allowed IP addresses in the secrets files (see
201the AUTHENTICATION section below).
202.TP
203.B bsdcomp \fInr,nt
204Request that the peer compress packets that it sends, using the
205BSD-Compress scheme, with a maximum code size of \fInr\fR bits, and
206agree to compress packets sent to the peer with a maximum code size of
207\fInt\fR bits.  If \fInt\fR is not specified, it defaults to the value
208given for \fInr\fR.  Values in the range 9 to 15 may be used for
209\fInr\fR and \fInt\fR; larger values give better compression but
210consume more kernel memory for compression dictionaries.
211Alternatively, a value of 0 for \fInr\fR or \fInt\fR disables
212compression in the corresponding direction.  Use \fInobsdcomp\fR or
213\fIbsdcomp 0\fR to disable BSD-Compress compression entirely.
214.TP
215.B cdtrcts
216Use a non-standard hardware flow control (i.e. DTR/CTS) to control
217the flow of data on the serial port.  If neither the \fIcrtscts\fR,
218the \fInocrtscts\fR, the \fIcdtrcts\fR nor the \fInocdtrcts\fR
219option is given, the hardware flow control setting for the serial
220port is left unchanged.
221Some serial ports (such as Macintosh serial ports) lack a true
222RTS output. Such serial ports use this mode to implement true
223bi-directional flow control. The sacrifice is that this flow
224control mode does not permit using DTR as a modem control line.
225.TP
226.B chap-interval \fIn
227If this option is given, pppd will rechallenge the peer every \fIn\fR
228seconds.
229.TP
230.B chap-max-challenge \fIn
231Set the maximum number of CHAP challenge transmissions to \fIn\fR
232(default 10).
233.TP
234.B chap-restart \fIn
235Set the CHAP restart interval (retransmission timeout for challenges)
236to \fIn\fR seconds (default 3).
237.TP
238.B connect-delay \fIn
239Wait for up \fIn\fR milliseconds after the connect script finishes for
240a valid PPP packet from the peer.  At the end of this time, or when a
241valid PPP packet is received from the peer, pppd will commence
242negotiation by sending its first LCP packet.  The default value is
2431000 (1 second).  This wait period only applies if the \fBconnect\fR
244or \fBpty\fR option is used.
245.TP
246.B debug
247Enables connection debugging facilities.
248If this option is given, pppd will log the contents of all
249control packets sent or received in a readable form.  The packets are
250logged through syslog with facility \fIdaemon\fR and level
251\fIdebug\fR.  This information can be directed to a file by setting up
252/etc/syslog.conf appropriately (see syslog.conf(5)).
253.TP
254.B default-asyncmap
255Disable asyncmap negotiation, forcing all control characters to be
256escaped for both the transmit and the receive direction.
257.TP
258.B default-mru
259Disable MRU [Maximum Receive Unit] negotiation.  With this option,
260pppd will use the default MRU value of 1500 bytes for both the
261transmit and receive direction.
262.TP
263.B deflate \fInr,nt
264Request that the peer compress packets that it sends, using the
265Deflate scheme, with a maximum window size of \fI2**nr\fR bytes, and
266agree to compress packets sent to the peer with a maximum window size
267of \fI2**nt\fR bytes.  If \fInt\fR is not specified, it defaults to
268the value given for \fInr\fR.  Values in the range 8 to 15 may be used
269for \fInr\fR and \fInt\fR; larger values give better compression but
270consume more kernel memory for compression dictionaries.
271Alternatively, a value of 0 for \fInr\fR or \fInt\fR disables
272compression in the corresponding direction.  Use \fInodeflate\fR or
273\fIdeflate 0\fR to disable Deflate compression entirely.  (Note: pppd
274requests Deflate compression in preference to BSD-Compress if the peer
275can do either.)
276.TP
277.B demand
278Initiate the link only on demand, i.e. when data traffic is present.
279With this option, the remote IP address must be specified by the user
280on the command line or in an options file.  Pppd will initially
281configure the interface and enable it for IP traffic without
282connecting to the peer.  When traffic is available, pppd will
283connect to the peer and perform negotiation, authentication, etc.
284When this is completed, pppd will commence passing data packets
285(i.e., IP packets) across the link.
286
287The \fIdemand\fR option implies the \fIpersist\fR option.  If this
288behaviour is not desired, use the \fInopersist\fR option after the
289\fIdemand\fR option.  The \fIidle\fR and \fIholdoff\fR
290options are also useful in conjuction with the \fIdemand\fR option.
291.TP
292.B domain \fId
293Append the domain name \fId\fR to the local host name for authentication
294purposes.  For example, if gethostname() returns the name porsche, but
295the fully qualified domain name is porsche.Quotron.COM, you could
296specify \fIdomain Quotron.COM\fR.  Pppd would then use the name
297\fIporsche.Quotron.COM\fR for looking up secrets in the secrets file,
298and as the default name to send to the peer when authenticating itself
299to the peer.  This option is privileged.
300.TP
301.B hide-password
302When logging the contents of PAP packets, this option causes pppd to
303exclude the password string from the log.  This is the default.
304.TP
305.B holdoff \fIn
306Specifies how many seconds to wait before re-initiating the link after
307it terminates.  This option only has any effect if the \fIpersist\fR
308or \fIdemand\fR option is used.  The holdoff period is not applied if
309the link was terminated because it was idle.
310.TP
311.B idle \fIn
312Specifies that pppd should disconnect if the link is idle for \fIn\fR
313seconds.  The link is idle when no data packets (i.e. IP packets) are
314being sent or received.  Note: it is not advisable to use this option
315with the \fIpersist\fR option without the \fIdemand\fR option.
316If the \fBactive-filter\fR
317option is given, data packets which are rejected by the specified
318activity filter also count as the link being idle.
319.TP
320.B ipcp-accept-local
321With this option, pppd will accept the peer's idea of our local IP
322address, even if the local IP address was specified in an option.
323.TP
324.B ipcp-accept-remote
325With this option, pppd will accept the peer's idea of its (remote) IP
326address, even if the remote IP address was specified in an option.
327.TP
328.B ipcp-max-configure \fIn
329Set the maximum number of IPCP configure-request transmissions to
330\fIn\fR (default 10).
331.TP
332.B ipcp-max-failure \fIn
333Set the maximum number of IPCP configure-NAKs returned before starting
334to send configure-Rejects instead to \fIn\fR (default 10).
335.TP
336.B ipcp-max-terminate \fIn
337Set the maximum number of IPCP terminate-request transmissions to
338\fIn\fR (default 3).
339.TP
340.B ipcp-restart \fIn
341Set the IPCP restart interval (retransmission timeout) to \fIn\fR
342seconds (default 3).
343.TP
344.B ipparam \fIstring
345Provides an extra parameter to the ip-up and ip-down scripts.  If this
346option is given, the \fIstring\fR supplied is given as the 6th
347parameter to those scripts.
348.TP
349.B ipv6cp-max-configure \fIn
350Set the maximum number of IPv6CP configure-request transmissions to
351\fIn\fR (default 10).
352.TP
353.B ipv6cp-max-failure \fIn
354Set the maximum number of IPv6CP configure-NAKs returned before starting
355to send configure-Rejects instead to \fIn\fR (default 10).
356.TP
357.B ipv6cp-max-terminate \fIn
358Set the maximum number of IPv6CP terminate-request transmissions to
359\fIn\fR (default 3).
360.TP
361.B ipv6cp-restart \fIn
362Set the IPv6CP restart interval (retransmission timeout) to \fIn\fR
363seconds (default 3).
364.TP
365.B ipx
366Enable the IPXCP and IPX protocols.  This option is presently only
367supported under Linux, and only if your kernel has been configured to
368include IPX support.
369.TP
370.B ipx-network \fIn
371Set the IPX network number in the IPXCP configure request frame to
372\fIn\fR, a hexadecimal number (without a leading 0x).  There is no
373valid default.  If this option is not specified, the network number is
374obtained from the peer.  If the peer does not have the network number,
375the IPX protocol will not be started.
376.TP
377.B ipx-node \fIn\fB:\fIm
378Set the IPX node numbers. The two node numbers are separated from each
379other with a colon character. The first number \fIn\fR is the local
380node number. The second number \fIm\fR is the peer's node number. Each
381node number is a hexadecimal number, at most 10 digits long. The node
382numbers on the ipx-network must be unique. There is no valid
383default. If this option is not specified then the node numbers are
384obtained from the peer.
385.TP
386.B ipx-router-name \fI<string>
387Set the name of the router. This is a string and is sent to the peer
388as information data.
389.TP
390.B ipx-routing \fIn
391Set the routing protocol to be received by this option. More than one
392instance of \fIipx-routing\fR may be specified. The '\fInone\fR'
393option (0) may be specified as the only instance of ipx-routing. The
394values may be \fI0\fR for \fINONE\fR, \fI2\fR for \fIRIP/SAP\fR, and
395\fI4\fR for \fINLSP\fR.
396.TP
397.B ipxcp-accept-local
398Accept the peer's NAK for the node number specified in the ipx-node
399option. If a node number was specified, and non-zero, the default is
400to insist that the value be used. If you include this option then you
401will permit the peer to override the entry of the node number.
402.TP
403.B ipxcp-accept-network
404Accept the peer's NAK for the network number specified in the
405ipx-network option. If a network number was specified, and non-zero, the
406default is to insist that the value be used. If you include this
407option then you will permit the peer to override the entry of the node
408number.
409.TP
410.B ipxcp-accept-remote
411Use the peer's network number specified in the configure request
412frame. If a node number was specified for the peer and this option was
413not specified, the peer will be forced to use the value which you have
414specified.
415.TP
416.B ipxcp-max-configure \fIn
417Set the maximum number of IPXCP configure request frames which the
418system will send to \fIn\fR. The default is 10.
419.TP
420.B ipxcp-max-failure \fIn
421Set the maximum number of IPXCP NAK frames which the local system will
422send before it rejects the options. The default value is 3.
423.TP
424.B ipxcp-max-terminate \fIn
425Set the maximum nuber of IPXCP terminate request frames before the
426local system considers that the peer is not listening to them. The
427default value is 3.
428.TP
429.B kdebug \fIn
430Enable debugging code in the kernel-level PPP driver.  The argument
431\fIn\fR is a number which is the sum of the following values: 1 to
432enable general debug messages, 2 to request that the contents of
433received packets be printed, and 4 to request that the contents of
434transmitted packets be printed.  On most systems, messages printed by
435the kernel are logged by syslog(1) to a file as directed in the
436/etc/syslog.conf configuration file.
437.TP
438.B ktune
439Enables pppd to alter kernel settings as appropriate.  Under Linux,
440pppd will enable IP forwarding (i.e. set /proc/sys/net/ipv4/ip_forward
441to 1) if the \fIproxyarp\fR option is used, and will enable the
442dynamic IP address option (i.e. set /proc/sys/net/ipv4/ip_dynaddr to
4431) in demand mode if the local address changes.
444.TP
445.B lcp-echo-failure \fIn
446If this option is given, pppd will presume the peer to be dead
447if \fIn\fR LCP echo-requests are sent without receiving a valid LCP
448echo-reply.  If this happens, pppd will terminate the
449connection.  Use of this option requires a non-zero value for the
450\fIlcp-echo-interval\fR parameter.  This option can be used to enable
451pppd to terminate after the physical connection has been broken
452(e.g., the modem has hung up) in situations where no hardware modem
453control lines are available.
454.TP
455.B lcp-echo-interval \fIn
456If this option is given, pppd will send an LCP echo-request frame to
457the peer every \fIn\fR seconds.  Normally the peer should respond to
458the echo-request by sending an echo-reply.  This option can be used
459with the \fIlcp-echo-failure\fR option to detect that the peer is no
460longer connected.
461.TP
462.B lcp-max-configure \fIn
463Set the maximum number of LCP configure-request transmissions to
464\fIn\fR (default 10).
465.TP
466.B lcp-max-failure \fIn
467Set the maximum number of LCP configure-NAKs returned before starting
468to send configure-Rejects instead to \fIn\fR (default 10).
469.TP
470.B lcp-max-terminate \fIn
471Set the maximum number of LCP terminate-request transmissions to
472\fIn\fR (default 3).
473.TP
474.B lcp-restart \fIn
475Set the LCP restart interval (retransmission timeout) to \fIn\fR
476seconds (default 3).
477.TP
478.B linkname \fIname\fR
479Sets the logical name of the link to \fIname\fR.  Pppd will create a
480file named \fBppp-\fIname\fB.pid\fR in /var/run (or /etc/ppp on some
481systems) containing its process ID.  This can be useful in determining
482which instance of pppd is responsible for the link to a given peer
483system.  This is a privileged option.
484.TP
485.B local
486Don't use the modem control lines.  With this option, pppd will ignore
487the state of the CD (Carrier Detect) signal from the modem and will
488not change the state of the DTR (Data Terminal Ready) signal.
489.TP
490.B logfd \fIn
491Send log messages to file descriptor \fIn\fR.  Pppd will send log
492messages to at most one file or file descriptor (as well as sending
493the log messages to syslog), so this option and the \fBlogfile\fR
494option are mutually exclusive.  The default is for pppd to send log
495messages to stdout (file descriptor 1), unless the serial port is
496already open on stdout.
497.TP
498.B logfile \fIfilename
499Append log messages to the file \fIfilename\fR (as well as sending the
500log messages to syslog).  The file is opened with the privileges of
501the user who invoked pppd, in append mode.
502.TP
503.B login
504Use the system password database for authenticating the peer using
505PAP, and record the user in the system wtmp file.  Note that the peer
506must have an entry in the /etc/ppp/pap-secrets file as well as the
507system password database to be allowed access.
508.TP
509.B maxconnect \fIn
510Terminate the connection when it has been available for network
511traffic for \fIn\fR seconds (i.e. \fIn\fR seconds after the first
512network control protocol comes up).
513.TP
514.B maxfail \fIn
515Terminate after \fIn\fR consecutive failed connection attempts.  A
516value of 0 means no limit.  The default value is 10.
517.TP
518.B modem
519Use the modem control lines.  This option is the default.  With this
520option, pppd will wait for the CD (Carrier Detect) signal from the
521modem to be asserted when opening the serial device (unless a connect
522script is specified), and it will drop the DTR (Data Terminal Ready)
523signal briefly when the connection is terminated and before executing
524the connect script.  On Ultrix, this option implies hardware flow
525control, as for the \fIcrtscts\fR option.
526.TP
527.B ms-dns \fI<addr>
528If pppd is acting as a server for Microsoft Windows clients, this
529option allows pppd to supply one or two DNS (Domain Name Server)
530addresses to the clients.  The first instance of this option specifies
531the primary DNS address; the second instance (if given) specifies the
532secondary DNS address.  (This option was present in some older
533versions of pppd under the name \fBdns-addr\fR.)
534.TP
535.B ms-wins \fI<addr>
536If pppd is acting as a server for Microsoft Windows or "Samba"
537clients, this option allows pppd to supply one or two WINS (Windows
538Internet Name Services) server addresses to the clients.  The first
539instance of this option specifies the primary WINS address; the second
540instance (if given) specifies the secondary WINS address.
541.TP
542.B name \fIname
543Set the name of the local system for authentication purposes to
544\fIname\fR.  This is a privileged option.  With this option, pppd will
545use lines in the secrets files which have \fIname\fR as the second
546field when looking for a secret to use in authenticating the peer.  In
547addition, unless overridden with the \fIuser\fR option, \fIname\fR
548will be used as the name to send to the peer when authenticating the
549local system to the peer.  (Note that pppd does not append the domain
550name to \fIname\fR.)
551.TP
552.B netmask \fIn
553Set the interface netmask to \fIn\fR, a 32 bit netmask in "decimal dot"
554notation (e.g. 255.255.255.0).  If this option is given, the value
555specified is ORed with the default netmask.  The default netmask is
556chosen based on the negotiated remote IP address; it is the
557appropriate network mask for the class of the remote IP address, ORed
558with the netmasks for any non point-to-point network interfaces in the
559system which are on the same network.  (Note: on some platforms, pppd
560will always use 255.255.255.255 for the netmask, if that is the only
561appropriate value for a point-to-point interface.)
562.TP
563.B noaccomp
564Disable Address/Control compression in both directions (send and
565receive).
566.TP
567.B noauth
568Do not require the peer to authenticate itself.  This option is
569privileged.
570.TP
571.B nobsdcomp
572Disables BSD-Compress compression; \fBpppd\fR will not request or
573agree to compress packets using the BSD-Compress scheme.
574.TP
575.B noccp
576Disable CCP (Compression Control Protocol) negotiation.  This option
577should only be required if the peer is buggy and gets confused by
578requests from pppd for CCP negotiation.
579.TP
580.B nocrtscts
581Disable hardware flow control (i.e. RTS/CTS) on the serial port.
582If neither the \fIcrtscts\fR nor the \fInocrtscts\fR nor the
583\fIcdtrcts\fR nor the \fInodtrcts\fR option is given, the hardware
584flow control setting for the serial port is left unchanged.
585.TP
586.B nodtrcts
587This option is a synonym for \fInocrtscts\fR. Either of these options will
588disable both forms of hardware flow control.
589.TP
590.B nodefaultroute
591Disable the \fIdefaultroute\fR option.  The system administrator who
592wishes to prevent users from creating default routes with pppd
593can do so by placing this option in the /etc/ppp/options file.
594.TP
595.B nodeflate
596Disables Deflate compression; pppd will not request or agree to
597compress packets using the Deflate scheme.
598.TP
599.B nodetach
600Don't detach from the controlling terminal.  Without this option, if a
601serial device other than the terminal on the standard input is
602specified, pppd will fork to become a background process.
603.TP
604.B noip
605Disable IPCP negotiation and IP communication.  This option should
606only be required if the peer is buggy and gets confused by requests
607from pppd for IPCP negotiation.
608.TP
609.B noipv6
610Disable IPv6CP negotiation and IPv6 communication. This option should
611only be required if the peer is buggy and gets confused by requests
612from pppd for IPv6CP negotiation.
613.TP
614.B noipdefault
615Disables the default behaviour when no local IP address is specified,
616which is to determine (if possible) the local IP address from the
617hostname.  With this option, the peer will have to supply the local IP
618address during IPCP negotiation (unless it specified explicitly on the
619command line or in an options file).
620.TP
621.B noipx
622Disable the IPXCP and IPX protocols.  This option should only be
623required if the peer is buggy and gets confused by requests from pppd
624for IPXCP negotiation.
625.TP
626.B noktune
627Opposite of the \fIktune\fR option; disables pppd from changing system
628settings.
629.TP
630.B nolog
631Do not send log messages to a file or file descriptor.  This option
632cancels the \fBlogfd\fR and \fBlogfile\fR options.
633.B nomagic
634Disable magic number negotiation.  With this option, pppd cannot
635detect a looped-back line.  This option should only be needed if the
636peer is buggy.
637.TP
638.B nopcomp
639Disable protocol field compression negotiation in both the receive and
640the transmit direction.
641.TP
642.B nopersist
643Exit once a connection has been made and terminated.  This is the
644default unless the \fIpersist\fR or \fIdemand\fR option has been
645specified.
646.TP
647.B nopredictor1
648Do not accept or agree to Predictor-1 compression.
649.TP
650.B noproxyarp
651Disable the \fIproxyarp\fR option.  The system administrator who
652wishes to prevent users from creating proxy ARP entries with pppd can
653do so by placing this option in the /etc/ppp/options file.
654.TP
655.B notty
656Normally, pppd requires a terminal device.  With this option, pppd
657will allocate itself a pseudo-tty master/slave pair and use the slave
658as its terminal device.  Pppd will create a child process to act as a
659`character shunt' to transfer characters between the pseudo-tty master
660and its standard input and output.  Thus pppd will transmit characters
661on its standard output and receive characters on its standard input
662even if they are not terminal devices.  This option increases the
663latency and CPU overhead of transferring data over the ppp interface
664as all of the characters sent and received must flow through the
665character shunt process.  An explicit device name may not be given if
666this option is used.
667.TP
668.B novj
669Disable Van Jacobson style TCP/IP header compression in both the
670transmit and the receive direction.
671.TP
672.B novjccomp
673Disable the connection-ID compression option in Van Jacobson style
674TCP/IP header compression.  With this option, pppd will not omit the
675connection-ID byte from Van Jacobson compressed TCP/IP headers, nor
676ask the peer to do so.
677.TP
678.B papcrypt
679Indicates that all secrets in the /etc/ppp/pap-secrets file which are
680used for checking the identity of the peer are encrypted, and thus
681pppd should not accept a password which, before encryption, is
682identical to the secret from the /etc/ppp/pap-secrets file.
683.TP
684.B pap-max-authreq \fIn
685Set the maximum number of PAP authenticate-request transmissions to
686\fIn\fR (default 10).
687.TP
688.B pap-restart \fIn
689Set the PAP restart interval (retransmission timeout) to \fIn\fR
690seconds (default 3).
691.TP
692.B pap-timeout \fIn
693Set the maximum time that pppd will wait for the peer to authenticate
694itself with PAP to \fIn\fR seconds (0 means no limit).
695.TP
696.B pass-filter \fIfilter-expression
697Specifies a packet filter to applied to data packets being sent or
698received to determine which packets should be allowed to pass.
699Packets which are rejected by the filter are silently discarded.  This
700option can be used to prevent specific network daemons (such as
701routed) using up link bandwidth, or to provide a basic firewall
702capability.
703The \fIfilter-expression\fR syntax is as described for tcpdump(1),
704except that qualifiers which are inappropriate for a PPP link, such as
705\fBether\fR and \fBarp\fR, are not permitted.  Generally the filter
706expression should be enclosed in single-quotes to prevent whitespace
707in the expression from being interpreted by the shell.  Note that it
708is possible to apply different constraints to incoming and outgoing
709packets using the \fBinbound\fR and \fBoutbound\fR qualifiers. This
710option is currently only available under NetBSD, and then only if both
711the kernel and pppd were compiled with PPP_FILTER defined.
712.TP
713.B persist
714Do not exit after a connection is terminated; instead try to reopen
715the connection.
716.TP
717.B plugin \fIfilename
718Load the shared library object file \fIfilename\fR as a plugin.  This
719is a privileged option.
720.TP
721.B predictor1
722Request that the peer compress frames that it sends using Predictor-1
723compression, and agree to compress transmitted frames with Predictor-1
724if requested.  This option has no effect unless the kernel driver
725supports Predictor-1 compression.
726.TP
727.B privgroup \fIgroup-name
728Allows members of group \fIgroup-name\fR to use privileged options.
729This is a privileged option.  Use of this option requires care as
730there is no guarantee that members of \fIgroup-name\fR cannot use pppd
731to become root themselves.  Consider it equivalent to putting the
732members of \fIgroup-name\fR in the kmem or disk group.
733.TP
734.B proxyarp
735Add an entry to this system's ARP [Address Resolution Protocol] table
736with the IP address of the peer and the Ethernet address of this
737system.  This will have the effect of making the peer appear to other
738systems to be on the local ethernet.
739.TP
740.B pty \fIscript
741Specifies that the command \fIscript\fR is to be used to communicate
742rather than a specific terminal device.  Pppd will allocate itself a
743pseudo-tty master/slave pair and use the slave as its terminal
744device.  The \fIscript\fR will be run in a child process with the
745pseudo-tty master as its standard input and output.  An explicit
746device name may not be given if this option is used.  (Note: if the
747\fIrecord\fR option is used in conjuction with the \fIpty\fR option,
748the child process will have pipes on its standard input and output.)
749.TP
750.B receive-all
751With this option, pppd will accept all control characters from the
752peer, including those marked in the receive asyncmap.  Without this
753option, pppd will discard those characters as specified in RFC1662.
754This option should only be needed if the peer is buggy.
755.TP
756.B record \fIfilename
757Specifies that pppd should record all characters sent and received to
758a file named \fIfilename\fR.  This file is opened in append mode,
759using the user's user-ID and permissions.  This option is implemented
760using a pseudo-tty and a process to transfer characters between the
761pseudo-tty and the real serial device, so it will increase the latency
762and CPU overhead of transferring data over the ppp interface.  The
763characters are stored in a tagged format with timestamps, which can be
764displayed in readable form using the pppdump(8) program.
765.TP
766.B remotename \fIname
767Set the assumed name of the remote system for authentication purposes
768to \fIname\fR.
769.TP
770.B refuse-chap
771With this option, pppd will not agree to authenticate itself to the
772peer using CHAP.
773.TP
774.B refuse-pap
775With this option, pppd will not agree to authenticate itself to the
776peer using PAP.
777.TP
778.B require-chap
779Require the peer to authenticate itself using CHAP [Challenge
780Handshake Authentication Protocol] authentication.
781.TP
782.B require-pap
783Require the peer to authenticate itself using PAP [Password
784Authentication Protocol] authentication.
785.TP
786.B show-password
787When logging the contents of PAP packets, this option causes pppd to
788show the password string in the log message.
789.TP
790.B silent
791With this option, pppd will not transmit LCP packets to initiate a
792connection until a valid LCP packet is received from the peer (as for
793the `passive' option with ancient versions of pppd).
794.TP
795.B sync
796Use synchronous HDLC serial encoding instead of asynchronous.
797The device used by pppd with this option must have sync support.
798Currently supports Microgate SyncLink adapters
799under Linux and FreeBSD 2.2.8 and later.
800.TP
801.B updetach
802With this option, pppd will detach from its controlling terminal once
803it has successfully established the ppp connection (to the point where
804the first network control protocol, usually the IP control protocol,
805has come up).
806.TP
807.B usehostname
808Enforce the use of the hostname (with domain name appended, if given)
809as the name of the local system for authentication purposes (overrides
810the \fIname\fR option).  This option is not normally needed since the
811\fIname\fR option is privileged.
812.TP
813.B usepeerdns
814Ask the peer for up to 2 DNS server addresses.  The addresses supplied
815by the peer (if any) are passed to the /etc/ppp/ip-up script in the
816environment variables DNS1 and DNS2.  In addition, pppd will create an
817/etc/ppp/resolv.conf file containing one or two nameserver lines with
818the address(es) supplied by the peer.
819.TP
820.B user \fIname
821Sets the name used for authenticating the local system to the peer to
822\fIname\fR.
823.TP
824.B vj-max-slots \fIn
825Sets the number of connection slots to be used by the Van Jacobson
826TCP/IP header compression and decompression code to \fIn\fR, which
827must be between 2 and 16 (inclusive).
828.TP
829.B welcome \fIscript
830Run the executable or shell command specified by \fIscript\fR before
831initiating PPP negotiation, after the connect script (if any) has
832completed.  A value for this option from a privileged source cannot be
833overridden by a non-privileged user.
834.TP
835.B xonxoff
836Use software flow control (i.e. XON/XOFF) to control the flow of data on
837the serial port.
838.SH OPTIONS FILES
839Options can be taken from files as well as the command line.  Pppd
840reads options from the files /etc/ppp/options, ~/.ppprc and
841/etc/ppp/options.\fIttyname\fR (in that order) before processing the
842options on the command line.  (In fact, the command-line options are
843scanned to find the terminal name before the options.\fIttyname\fR
844file is read.)  In forming the name of the options.\fIttyname\fR file,
845the initial /dev/ is removed from the terminal name, and any remaining
846/ characters are replaced with dots.
847.PP
848An options file is parsed into a series of words, delimited by
849whitespace.  Whitespace can be included in a word by enclosing the
850word in double-quotes (").  A backslash (\\) quotes the following character.
851A hash (#) starts a comment, which continues until the end of the
852line.  There is no restriction on using the \fIfile\fR or \fIcall\fR
853options within an options file.
854.SH SECURITY
855.I pppd
856provides system administrators with sufficient access control that PPP
857access to a server machine can be provided to legitimate users without
858fear of compromising the security of the server or the network it's
859on.  This control is provided through restrictions on which IP
860addresses the peer may use, based on its authenticated identity (if
861any), and through restrictions on which options a non-privileged user
862may use.  Several of pppd's options are privileged, in particular
863those which permit potentially insecure configurations; these options
864are only accepted in files which are under the control of the system
865administrator, or if pppd is being run by root.
866.PP
867The default behaviour of pppd is to allow an unauthenticated peer to
868use a given IP address only if the system does not already have a
869route to that IP address.  For example, a system with a
870permanent connection to the wider internet will normally have a
871default route, and thus all peers will have to authenticate themselves
872in order to set up a connection.  On such a system, the \fIauth\fR
873option is the default.  On the other hand, a system where the
874PPP link is the only connection to the internet will not normally have
875a default route, so the peer will be able to use almost any IP address
876without authenticating itself.
877.PP
878As indicated above, some security-sensitive options are privileged,
879which means that they may not be used by an ordinary non-privileged
880user running a setuid-root pppd, either on the command line, in the
881user's ~/.ppprc file, or in an options file read using the \fIfile\fR
882option.  Privileged options may be used in /etc/ppp/options file or in
883an options file read using the \fIcall\fR option.  If pppd is being
884run by the root user, privileged options can be used without
885restriction.
886.PP
887When opening the device, pppd uses either the invoking user's user ID
888or the root UID (that is, 0), depending on whether the device name was
889specified by the user or the system administrator.  If the device name
890comes from a privileged source, that is, /etc/ppp/options or an
891options file read using the \fIcall\fR option, pppd uses full root
892privileges when opening the device.  Thus, by creating an appropriate
893file under /etc/ppp/peers, the system administrator can allow users to
894establish a ppp connection via a device which they would not normally
895have permission to access.  Otherwise pppd uses the invoking user's
896real UID when opening the device.
897.SH AUTHENTICATION
898Authentication is the process whereby one peer convinces the other of
899its identity.  This involves the first peer sending its name to the
900other, together with some kind of secret information which could only
901come from the genuine authorized user of that name.  In such an
902exchange, we will call the first peer the "client" and the other the
903"server".  The client has a name by which it identifies itself to the
904server, and the server also has a name by which it identifies itself
905to the client.  Generally the genuine client shares some secret (or
906password) with the server, and authenticates itself by proving that it
907knows that secret.  Very often, the names used for authentication
908correspond to the internet hostnames of the peers, but this is not
909essential.
910.LP
911At present, pppd supports two authentication protocols: the Password
912Authentication Protocol (PAP) and the Challenge Handshake
913Authentication Protocol (CHAP).  PAP involves the client sending its
914name and a cleartext password to the server to authenticate itself.
915In contrast, the server initiates the CHAP authentication exchange by
916sending a challenge to the client (the challenge packet includes the
917server's name).  The client must respond with a response which
918includes its name plus a hash value derived from the shared secret and
919the challenge, in order to prove that it knows the secret.
920.LP
921The PPP protocol, being symmetrical, allows both peers to require the
922other to authenticate itself.  In that case, two separate and
923independent authentication exchanges will occur.  The two exchanges
924could use different authentication protocols, and in principle,
925different names could be used in the two exchanges.
926.LP
927The default behaviour of pppd is to agree to authenticate if
928requested, and to not require authentication from the peer.  However,
929pppd will not agree to authenticate itself with a particular protocol
930if it has no secrets which could be used to do so.
931.LP
932Pppd stores secrets for use in authentication in secrets
933files (/etc/ppp/pap-secrets for PAP, /etc/ppp/chap-secrets for CHAP).
934Both secrets files have the same format.  The secrets files can
935contain secrets for pppd to use in authenticating itself to other
936systems, as well as secrets for pppd to use when authenticating other
937systems to itself.
938.LP
939Each line in a secrets file contains one secret.  A given secret is
940specific to a particular combination of client and server - it can
941only be used by that client to authenticate itself to that server.
942Thus each line in a secrets file has at least 3 fields: the name of
943the client, the name of the server, and the secret.  These fields may
944be followed by a list of the IP addresses that the specified client
945may use when connecting to the specified server.
946.LP
947A secrets file is parsed into words as for a options file, so the
948client name, server name and secrets fields must each be one word,
949with any embedded spaces or other special characters quoted or
950escaped.  Note that case is significant in the client and server names
951and in the secret.
952.LP
953If the secret starts with an `@', what follows is assumed to be the
954name of a file from which to read the secret.  A "*" as the client or
955server name matches any name.  When selecting a secret, pppd takes the
956best match, i.e.  the match with the fewest wildcards.
957.LP
958Any following words on the same line are taken to be a list of
959acceptable IP addresses for that client.  If there are only 3 words on
960the line, or if the first word is "-", then all IP addresses are
961disallowed.  To allow any address, use "*".  A word starting with "!"
962indicates that the specified address is \fInot\fR acceptable.  An
963address may be followed by "/" and a number \fIn\fR, to indicate a
964whole subnet, i.e. all addresses which have the same value in the most
965significant \fIn\fR bits.  In this form, the address may be followed
966by a plus sign ("+") to indicate that one address from the subnet is
967authorized, based on the ppp network interface unit number in use.
968In this case, the host part of the address will be set to the unit
969number plus one.
970.LP
971Thus a secrets file contains both secrets for use in authenticating
972other hosts, plus secrets which we use for authenticating ourselves to
973others.  When pppd is authenticating the peer (checking the peer's
974identity), it chooses a secret with the peer's name in the first
975field and the name of the local system in the second field.  The
976name of the local system defaults to the hostname, with the domain
977name appended if the \fIdomain\fR option is used.  This default can be
978overridden with the \fIname\fR option, except when the
979\fIusehostname\fR option is used.
980.LP
981When pppd is choosing a secret to use in authenticating itself to the
982peer, it first determines what name it is going to use to identify
983itself to the peer.  This name can be specified by the user with the
984\fIuser\fR option.  If this option is not used, the name defaults to
985the name of the local system, determined as described in the previous
986paragraph.  Then pppd looks for a secret with this name in the first
987field and the peer's name in the second field.  Pppd will know the
988name of the peer if CHAP authentication is being used, because the
989peer will have sent it in the challenge packet.  However, if PAP is being
990used, pppd will have to determine the peer's name from the options
991specified by the user.  The user can specify the peer's name directly
992with the \fIremotename\fR option.  Otherwise, if the remote IP address
993was specified by a name (rather than in numeric form), that name will
994be used as the peer's name.  Failing that, pppd will use the null
995string as the peer's name.
996.LP
997When authenticating the peer with PAP, the supplied password is first
998compared with the secret from the secrets file.  If the password
999doesn't match the secret, the password is encrypted using crypt() and
1000checked against the secret again.  Thus secrets for authenticating the
1001peer can be stored in encrypted form if desired.  If the
1002\fIpapcrypt\fR option is given, the first (unencrypted) comparison is
1003omitted, for better security.
1004.LP
1005Furthermore, if the \fIlogin\fR option was specified, the username and
1006password are also checked against the system password database.  Thus,
1007the system administrator can set up the pap-secrets file to allow PPP
1008access only to certain users, and to restrict the set of IP addresses
1009that each user can use.  Typically, when using the \fIlogin\fR option,
1010the secret in /etc/ppp/pap-secrets would be "", which will match any
1011password supplied by the peer.  This avoids the need to have the same
1012secret in two places.
1013.LP
1014Authentication must be satisfactorily completed before IPCP (or any
1015other Network Control Protocol) can be started.  If the peer is
1016required to authenticate itself, and fails to do so, pppd will
1017terminated the link (by closing LCP).  If IPCP negotiates an
1018unacceptable IP address for the remote host, IPCP will be closed.  IP
1019packets can only be sent or received when IPCP is open.
1020.LP
1021In some cases it is desirable to allow some hosts which can't
1022authenticate themselves to connect and use one of a restricted set of
1023IP addresses, even when the local host generally requires
1024authentication.  If the peer refuses to authenticate itself when
1025requested, pppd takes that as equivalent to authenticating with PAP
1026using the empty string for the username and password.  Thus, by adding
1027a line to the pap-secrets file which specifies the empty string for
1028the client and password, it is possible to allow restricted access to
1029hosts which refuse to authenticate themselves.
1030.SH ROUTING
1031.LP
1032When IPCP negotiation is completed successfully, pppd will inform the
1033kernel of the local and remote IP addresses for the ppp interface.
1034This is sufficient to create a host route to the remote end of the
1035link, which will enable the peers to exchange IP packets.
1036Communication with other machines generally requires further
1037modification to routing tables and/or ARP (Address Resolution
1038Protocol) tables.  In most cases the \fIdefaultroute\fR and/or
1039\fIproxyarp\fR options are sufficient for this, but in some cases
1040further intervention is required.  The /etc/ppp/ip-up script can be
1041used for this.
1042.LP
1043Sometimes it is desirable to add a default route through the remote
1044host, as in the case of a machine whose only connection to the
1045Internet is through the ppp interface.  The \fIdefaultroute\fR option
1046causes pppd to create such a default route when IPCP comes up, and
1047delete it when the link is terminated.
1048.LP
1049In some cases it is desirable to use proxy ARP, for example on a
1050server machine connected to a LAN, in order to allow other hosts to
1051communicate with the remote host.  The \fIproxyarp\fR option causes
1052pppd to look for a network interface on the same subnet as the remote
1053host (an interface supporting broadcast and ARP, which is up and not a
1054point-to-point or loopback interface).  If found, pppd creates a
1055permanent, published ARP entry with the IP address of the remote host
1056and the hardware address of the network interface found.
1057.LP
1058When the \fIdemand\fR option is used, the interface IP addresses have
1059already been set at the point when IPCP comes up.  If pppd has not
1060been able to negotiate the same addresses that it used to configure
1061the interface (for example when the peer is an ISP that uses dynamic
1062IP address assignment), pppd has to change the interface IP addresses
1063to the negotiated addresses.  This may disrupt existing connections,
1064and the use of demand dialling with peers that do dynamic IP address
1065assignment is not recommended.
1066.SH EXAMPLES
1067.LP
1068The following examples assume that the /etc/ppp/options file contains
1069the \fIauth\fR option (as in the default /etc/ppp/options file in the
1070ppp distribution).
1071.LP
1072Probably the most common use of pppd is to dial out to an ISP.  This
1073can be done with a command such as
1074.IP
1075pppd call isp
1076.LP
1077where the /etc/ppp/peers/isp file is set up by the system
1078administrator to contain something like this:
1079.IP
1080ttyS0 19200 crtscts
1081.br
1082connect '/usr/sbin/chat -v -f /etc/ppp/chat-isp'
1083.br
1084noauth
1085.LP
1086In this example, we are using chat to dial the ISP's modem and go
1087through any logon sequence required.  The /etc/ppp/chat-isp file
1088contains the script used by chat; it could for example contain
1089something like this:
1090.IP
1091ABORT "NO CARRIER"
1092.br
1093ABORT "NO DIALTONE"
1094.br
1095ABORT "ERROR"
1096.br
1097ABORT "NO ANSWER"
1098.br
1099ABORT "BUSY"
1100.br
1101ABORT "Username/Password Incorrect"
1102.br
1103"" "at"
1104.br
1105OK "at&d0&c1"
1106.br
1107OK "atdt2468135"
1108.br
1109"name:" "^Umyuserid"
1110.br
1111"word:" "\\qmypassword"
1112.br
1113"ispts" "\\q^Uppp"
1114.br
1115"~-^Uppp-~"
1116.LP
1117See the chat(8) man page for details of chat scripts.
1118.LP
1119Pppd can also be used to provide a dial-in ppp service for users.  If
1120the users already have login accounts, the simplest way to set up the
1121ppp service is to let the users log in to their accounts and run pppd
1122(installed setuid-root) with a command such as
1123.IP
1124pppd proxyarp
1125.LP
1126To allow a user to use the PPP facilities, you need to allocate an IP
1127address for that user's machine and create an entry in
1128/etc/ppp/pap-secrets or /etc/ppp/chap-secrets (depending on which
1129authentication method the PPP implementation on the user's machine
1130supports), so that the user's
1131machine can authenticate itself.  For example, if Joe has a machine
1132called "joespc" which is to be allowed to dial in to the machine
1133called "server" and use the IP address joespc.my.net, you would add an
1134entry like this to /etc/ppp/pap-secrets or /etc/ppp/chap-secrets:
1135.IP
1136joespc  server  "joe's secret"  joespc.my.net
1137.LP
1138Alternatively, you can create a username called (for example) "ppp",
1139whose login shell is pppd and whose home directory is /etc/ppp.
1140Options to be used when pppd is run this way can be put in
1141/etc/ppp/.ppprc.
1142.LP
1143If your serial connection is any more complicated than a piece of
1144wire, you may need to arrange for some control characters to be
1145escaped.  In particular, it is often useful to escape XON (^Q) and
1146XOFF (^S), using \fIasyncmap a0000\fR.  If the path includes a telnet,
1147you probably should escape ^] as well (\fIasyncmap 200a0000\fR).  If
1148the path includes an rlogin, you will need to use the \fIescape ff\fR
1149option on the end which is running the rlogin client, since many
1150rlogin implementations are not transparent; they will remove the
1151sequence [0xff, 0xff, 0x73, 0x73, followed by any 8 bytes] from the
1152stream.
1153.SH DIAGNOSTICS
1154.LP
1155Messages are sent to the syslog daemon using facility LOG_DAEMON.
1156(This can be overriden by recompiling pppd with the macro
1157LOG_PPP defined as the desired facility.)  In order to see the error
1158and debug messages, you will need to edit your /etc/syslog.conf file
1159to direct the messages to the desired output device or file.
1160.LP
1161The \fIdebug\fR option causes the contents of all control packets sent
1162or received to be logged, that is, all LCP, PAP, CHAP or IPCP packets.
1163This can be useful if the PPP negotiation does not succeed or if
1164authentication fails.
1165If debugging is enabled at compile time, the \fIdebug\fR option also
1166causes other debugging messages to be logged.
1167.LP
1168Debugging can also be enabled or disabled by sending a SIGUSR1 signal
1169to the pppd process.  This signal acts as a toggle.
1170.SH EXIT STATUS
1171The exit status of pppd is set to indicate whether any error was
1172detected, or the reason for the link being terminated.  The values
1173used are:
1174.TP
1175.B 0
1176Pppd has detached, or otherwise the connection was successfully
1177established and terminated at the peer's request.
1178.TP
1179.B 1
1180An immediately fatal error of some kind occurred, such as an essential
1181system call failing, or running out of virtual memory.
1182.TP
1183.B 2
1184An error was detected in processing the options given, such as two
1185mutually exclusive options being used.
1186.TP
1187.B 3
1188Pppd is not setuid-root and the invoking user is not root.
1189.TP
1190.B 4
1191The kernel does not support PPP, for example, the PPP kernel driver is
1192not included or cannot be loaded.
1193.TP
1194.B 5
1195Pppd terminated because it was sent a SIGINT, SIGTERM or SIGHUP
1196signal.
1197.TP
1198.B 6
1199The serial port could not be locked.
1200.TP
1201.B 7
1202The serial port could not be opened.
1203.TP
1204.B 8
1205The connect script failed (returned a non-zero exit status).
1206.TP
1207.B 9
1208The command specified as the argument to the \fIpty\fR option could
1209not be run.
1210.TP
1211.B 10
1212The PPP negotiation failed, that is, it didn't reach the point where
1213at least one network protocol (e.g. IP) was running.
1214.TP
1215.B 11
1216The peer system failed (or refused) to authenticate itself.
1217.TP
1218.B 12
1219The link was established successfully and terminated because it was
1220idle.
1221.TP
1222.B 13
1223The link was established successfully and terminated because the
1224connect time limit was reached.
1225.TP
1226.B 14
1227Callback was negotiated and an incoming call should arrive shortly.
1228.TP
1229.B 15
1230The link was terminated because the peer is not responding to echo
1231requests.
1232.TP
1233.B 16
1234The link was terminated by the modem hanging up.
1235.TP
1236.B 17
1237The PPP negotiation failed because serial loopback was detected.
1238.TP
1239.B 18
1240The init script failed (returned a non-zero exit status).
1241.TP
1242.B 19
1243We failed to authenticate ourselves to the peer.
1244.SH SCRIPTS
1245Pppd invokes scripts at various stages in its processing which can be
1246used to perform site-specific ancillary processing.  These scripts are
1247usually shell scripts, but could be executable code files instead.
1248Pppd does not wait for the scripts to finish.  The scripts are
1249executed as root (with the real and effective user-id set to 0), so
1250that they can do things such as update routing tables or run
1251privileged daemons.  Be careful that the contents of these scripts do
1252not compromise your system's security.  Pppd runs the scripts with
1253standard input, output and error redirected to /dev/null, and with an
1254environment that is empty except for some environment variables that
1255give information about the link.  The environment variables that pppd
1256sets are:
1257.TP
1258.B DEVICE
1259The name of the serial tty device being used.
1260.TP
1261.B IFNAME
1262The name of the network interface being used.
1263.TP
1264.B IPLOCAL
1265The IP address for the local end of the link.  This is only set when
1266IPCP has come up.
1267.TP
1268.B IPREMOTE
1269The IP address for the remote end of the link.  This is only set when
1270IPCP has come up.
1271.TP
1272.B PEERNAME
1273The authenticated name of the peer.  This is only set if the peer
1274authenticates itself.
1275.TP
1276.B SPEED
1277The baud rate of the tty device.
1278.TP
1279.B ORIG_UID
1280The real user-id of the user who invoked pppd.
1281.TP
1282.B PPPLOGNAME
1283The username of the real user-id that invoked pppd. This is always set.
1284.P
1285For the ip-down and auth-down scripts, pppd also sets the following
1286variables giving statistics for the connection:
1287.TP
1288.B CONNECT_TIME
1289The number of seconds from when the PPP negotiation started until the
1290connection was terminated.
1291.TP
1292.B BYTES_SENT
1293The number of bytes sent (at the level of the serial port) during the
1294connection.
1295.TP
1296.B BYTES_RCVD
1297The number of bytes received (at the level of the serial port) during
1298the connection.
1299.TP
1300.B LINKNAME
1301The logical name of the link, set with the \fIlinkname\fR option.
1302.P
1303Pppd invokes the following scripts, if they exist.  It is not an error
1304if they don't exist.
1305.TP
1306.B /etc/ppp/auth-up
1307A program or script which is executed after the remote system
1308successfully authenticates itself.  It is executed with the parameters
1309.IP
1310\fIinterface-name peer-name user-name tty-device speed\fR
1311.IP
1312Note that this script is not executed if the peer doesn't authenticate
1313itself, for example when the \fInoauth\fR option is used.
1314.TP
1315.B /etc/ppp/auth-down
1316A program or script which is executed when the link goes down, if
1317/etc/ppp/auth-up was previously executed.  It is executed in the same
1318manner with the same parameters as /etc/ppp/auth-up.
1319.TP
1320.B /etc/ppp/ip-up
1321A program or script which is executed when the link is available for
1322sending and receiving IP packets (that is, IPCP has come up).  It is
1323executed with the parameters
1324.IP
1325\fIinterface-name tty-device speed local-IP-address
1326remote-IP-address ipparam\fR
1327.TP
1328.B /etc/ppp/ip-down
1329A program or script which is executed when the link is no longer
1330available for sending and receiving IP packets.  This script can be
1331used for undoing the effects of the /etc/ppp/ip-up script.  It is
1332invoked in the same manner and with the same parameters as the ip-up
1333script.
1334.TP
1335.B /etc/ppp/ipv6-up
1336Like /etc/ppp/ip-up, except that it is executed when the link is available
1337for sending and receiving IPv6 packets. It is executed with the parameters
1338.IP
1339\fIinterface-name tty-device speed local-link-local-address
1340remote-link-local-address ipparam\fR
1341.TP
1342.B /etc/ppp/ipv6-down
1343Similar to /etc/ppp/ip-down, but it is executed when IPv6 packets can no
1344longer be transmitted on the link. It is executed with the same parameters
1345as the ipv6-up script.
1346.TP
1347.B /etc/ppp/ipx-up
1348A program or script which is executed when the link is available for
1349sending and receiving IPX packets (that is, IPXCP has come up).  It is
1350executed with the parameters
1351.IP
1352\fIinterface-name tty-device speed network-number local-IPX-node-address
1353remote-IPX-node-address local-IPX-routing-protocol remote-IPX-routing-protocol
1354local-IPX-router-name remote-IPX-router-name ipparam pppd-pid\fR
1355.IP
1356The local-IPX-routing-protocol and remote-IPX-routing-protocol field
1357may be one of the following:
1358.IP
1359NONE      to indicate that there is no routing protocol
1360.br
1361RIP       to indicate that RIP/SAP should be used
1362.br
1363NLSP      to indicate that Novell NLSP should be used
1364.br
1365RIP NLSP  to indicate that both RIP/SAP and NLSP should be used
1366.TP
1367.B /etc/ppp/ipx-down
1368A program or script which is executed when the link is no longer
1369available for sending and receiving IPX packets.  This script can be
1370used for undoing the effects of the /etc/ppp/ipx-up script.  It is
1371invoked in the same manner and with the same parameters as the ipx-up
1372script.
1373.SH FILES
1374.TP
1375.B /var/run/ppp\fIn\fB.pid \fR(BSD or Linux), \fB/etc/ppp/ppp\fIn\fB.pid \fR(others)
1376Process-ID for pppd process on ppp interface unit \fIn\fR.
1377.TP
1378.B /var/run/ppp-\fIname\fB.pid \fR(BSD or Linux), \fB/etc/ppp/ppp-\fIname\fB.pid \fR(others)
1379Process-ID for pppd process for logical link \fIname\fR (see the
1380\fIlinkname\fR option).
1381.TP
1382.B /etc/ppp/pap-secrets
1383Usernames, passwords and IP addresses for PAP authentication.  This
1384file should be owned by root and not readable or writable by any other
1385user.  Pppd will log a warning if this is not the case.
1386.TP
1387.B /etc/ppp/chap-secrets
1388Names, secrets and IP addresses for CHAP authentication.  As for
1389/etc/ppp/pap-secrets, this file should be owned by root and not
1390readable or writable by any other user.  Pppd will log a warning if
1391this is not the case.
1392.TP
1393.B /etc/ppp/options
1394System default options for pppd, read before user default options or
1395command-line options.
1396.TP
1397.B ~/.ppprc
1398User default options, read before /etc/ppp/options.\fIttyname\fR.
1399.TP
1400.B /etc/ppp/options.\fIttyname
1401System default options for the serial port being used, read after
1402~/.ppprc.  In forming the \fIttyname\fR part of this
1403filename, an initial /dev/ is stripped from the port name (if
1404present), and any slashes in the remaining part are converted to
1405dots.
1406.TP
1407.B /etc/ppp/peers
1408A directory containing options files which may contain privileged
1409options, even if pppd was invoked by a user other than root.  The
1410system administrator can create options files in this directory to
1411permit non-privileged users to dial out without requiring the peer to
1412authenticate, but only to certain trusted peers.
1413.SH SEE ALSO
1414.TP
1415.B RFC1144
1416Jacobson, V.
1417\fICompressing TCP/IP headers for low-speed serial links.\fR
1418February 1990.
1419.TP
1420.B RFC1321
1421Rivest, R.
1422.I The MD5 Message-Digest Algorithm.
1423April 1992.
1424.TP
1425.B RFC1332
1426McGregor, G.
1427.I PPP Internet Protocol Control Protocol (IPCP).
1428May 1992.
1429.TP
1430.B RFC1334
1431Lloyd, B.; Simpson, W.A.
1432.I PPP authentication protocols.
1433October 1992.
1434.TP
1435.B RFC1661
1436Simpson, W.A.
1437.I The Point\-to\-Point Protocol (PPP).
1438July 1994.
1439.TP
1440.B RFC1662
1441Simpson, W.A.
1442.I PPP in HDLC-like Framing.
1443July 1994.
1444.TP
1445.B RFC2472
1446Haskin, D.
1447.I IP Version 6 over PPP
1448December 1998.
1449.SH NOTES
1450The following signals have the specified effect when sent to pppd.
1451.TP
1452.B SIGINT, SIGTERM
1453These signals cause pppd to terminate the link (by closing LCP),
1454restore the serial device settings, and exit.
1455.TP
1456.B SIGHUP
1457This signal causes pppd to terminate the link, restore the serial
1458device settings, and close the serial device.  If the \fIpersist\fR or
1459\fIdemand\fR option has been specified, pppd will try to reopen the
1460serial device and start another connection (after the holdoff period).
1461Otherwise pppd will exit.  If this signal is received during the
1462holdoff period, it causes pppd to end the holdoff period immediately.
1463.TP
1464.B SIGUSR1
1465This signal toggles the state of the \fIdebug\fR option.
1466.TP
1467.B SIGUSR2
1468This signal causes pppd to renegotiate compression.  This can be
1469useful to re-enable compression after it has been disabled as a result
1470of a fatal decompression error.  (Fatal decompression errors generally
1471indicate a bug in one or other implementation.)
1472
1473.SH AUTHORS
1474Paul Mackerras (Paul.Mackerras@cs.anu.edu.au), based on earlier work by
1475Drew Perkins,
1476Brad Clements,
1477Karl Fox,
1478Greg Christy,
1479and
1480Brad Parker.
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