1 .\" manual page [] for pppd 2.3
2 .\" $Id: pppd.8,v 1.46 1999/08/24 05:31:10 paulus Exp $
4 .\" SS subsection heading
6 .\" IP indented paragraph
10 pppd \- Point to Point Protocol daemon
22 The Point-to-Point Protocol (PPP) provides a method for transmitting
23 datagrams over serial point-to-point links. PPP
24 is composed of three parts: a method for encapsulating datagrams over
25 serial links, an extensible Link Control Protocol (LCP), and
26 a family of Network Control Protocols (NCP) for establishing
27 and configuring different network-layer protocols.
29 The encapsulation scheme is provided by driver code in the kernel.
30 Pppd provides the basic LCP, authentication support, and an NCP for
31 establishing and configuring the Internet Protocol (IP) (called the IP
32 Control Protocol, IPCP).
33 .SH FREQUENTLY USED OPTIONS
36 Communicate over the named device. The string "/dev/" is prepended if
37 necessary. If no device name is given, or if the name of the terminal
38 connected to the standard input is given, pppd will use that terminal,
39 and will not fork to put itself in the background. A value for this
40 option from a privileged source cannot be overridden by a
44 Set the baud rate to <speed> (a decimal number). On systems such as
45 4.4BSD and NetBSD, any speed can be specified. Other systems
46 (e.g. SunOS) allow only a limited set of speeds.
49 Set the async character map to <map>. This map describes which
50 control characters cannot be successfully received over the serial
51 line. Pppd will ask the peer to send these characters as a 2-byte
52 escape sequence. The argument is a 32 bit hex number with each bit
53 representing a character to escape. Bit 0 (00000001) represents the
54 character 0x00; bit 31 (80000000) represents the character 0x1f or ^_.
55 If multiple \fIasyncmap\fR options are given, the values are ORed
56 together. If no \fIasyncmap\fR option is given, no async character
57 map will be negotiated for the receive direction; the peer should then
58 escape \fIall\fR control characters. To escape transmitted
59 characters, use the \fIescape\fR option.
62 Require the peer to authenticate itself before allowing network
63 packets to be sent or received. This option is the default if the
64 system has a default route. If neither this option nor the
65 \fInoauth\fR option is specified, pppd will only allow the peer to use
66 IP addresses to which the system does not already have a route.
69 Read options from the file /etc/ppp/peers/\fIname\fR. This file may
70 contain privileged options, such as \fInoauth\fR, even if pppd
71 is not being run by root. The \fIname\fR string may not begin with /
72 or include .. as a pathname component. The format of the options file
76 Use the executable or shell command specified by \fIscript\fR to set
77 up the serial line. This script would typically use the chat(8)
78 program to dial the modem and start the remote ppp session. A value
79 for this option from a privileged source cannot be overridden by a
83 Use hardware flow control (i.e. RTS/CTS) to control the flow of
84 data on the serial port. If neither the \fIcrtscts\fR, the
85 \fInocrtscts\fR, the \fIcdtrcts\fR nor the \fInocdtrcts\fR option
86 is given, the hardware flow control setting for the serial port is
88 Some serial ports (such as Macintosh serial ports) lack a true
89 RTS output. Such serial ports use this mode to implement
90 unidirectional flow control. The serial port will
91 suspend transmission when requested by the modem (via CTS)
92 but will be unable to request the modem stop sending to the
93 computer. This mode retains the ability to use DTR as
97 Use a non-standard hardware flow control (i.e. DTR/CTS) to control
98 the flow of data on the serial port. If neither the \fIcrtscts\fR,
99 the \fInocrtscts\fR, the \fIcdtrcts\fR nor the \fInocdtrcts\fR
100 option is given, the hardware flow control setting for the serial
101 port is left unchanged.
102 Some serial ports (such as Macintosh serial ports) lack a true
103 RTS output. Such serial ports use this mode to implement true
104 bi-directional flow control. The sacrifice is that this flow
105 control mode does not permit using DTR as a modem control line.
108 Add a default route to the system routing tables, using the peer as
109 the gateway, when IPCP negotiation is successfully completed.
110 This entry is removed when the PPP connection is broken. This option
111 is privileged if the \fInodefaultroute\fR option has been specified.
113 .B disconnect \fIscript
114 Run the executable or shell command specified by \fIscript\fR after
115 pppd has terminated the link. This script could, for example, issue
116 commands to the modem to cause it to hang up if hardware modem control
117 signals were not available. The disconnect script is not run if the
118 modem has already hung up. A value for this option from a privileged
119 source cannot be overridden by a non-privileged user.
121 .B escape \fIxx,yy,...
122 Specifies that certain characters should be escaped on transmission
123 (regardless of whether the peer requests them to be escaped with its
124 async control character map). The characters to be escaped are
125 specified as a list of hex numbers separated by commas. Note that
126 almost any character can be specified for the \fIescape\fR option,
127 unlike the \fIasyncmap\fR option which only allows control characters
128 to be specified. The characters which may not be escaped are those
129 with hex values 0x20 - 0x3f or 0x5e.
132 Read options from file \fIname\fR (the format is described below).
133 The file must be readable by the user who has invoked pppd.
136 Run the executable or shell command specified by \fIscript\fR to
137 initialize the serial line. This script would typically use the
138 chat(8) program to configure the modem to enable auto answer. A value
139 for this option from a privileged source cannot be overridden by a
143 Specifies that pppd should create a UUCP-style lock file for the
144 serial device to ensure exclusive access to the device.
147 Set the MRU [Maximum Receive Unit] value to \fIn\fR. Pppd
148 will ask the peer to send packets of no more than \fIn\fR bytes. The
149 minimum MRU value is 128. The default MRU value is 1500. A value of
150 296 is recommended for slow links (40 bytes for TCP/IP header + 256
151 bytes of data). (Note that for IPv6 MRU must be at least 1280)
154 Set the MTU [Maximum Transmit Unit] value to \fIn\fR. Unless the
155 peer requests a smaller value via MRU negotiation, pppd will
156 request that the kernel networking code send data packets of no more
157 than \fIn\fR bytes through the PPP network interface. (Note that for
158 IPv6 MTU must be at least 1280)
161 Enables the "passive" option in the LCP. With this option, pppd will
162 attempt to initiate a connection; if no reply is received from the
163 peer, pppd will then just wait passively for a valid LCP packet from
164 the peer, instead of exiting, as it would without this option.
167 .I <local_IP_address>\fB:\fI<remote_IP_address>
168 Set the local and/or remote interface IP addresses. Either one may be
169 omitted. The IP addresses can be specified with a host name or in
170 decimal dot notation (e.g. 150.234.56.78). The default local
171 address is the (first) IP address of the system (unless the
173 option is given). The remote address will be obtained from the peer
174 if not specified in any option. Thus, in simple cases, this option is
175 not required. If a local and/or remote IP address is specified with
177 will not accept a different value from the peer in the IPCP
178 negotiation, unless the \fIipcp-accept-local\fR and/or
179 \fIipcp-accept-remote\fR options are given, respectively.
181 .B ipv6 \fI<local_interface_identifier>\fR,\fI<remote_interface_identifier>
182 Set the local and/or remote 64-bit interface identifier. Either one may be
183 omitted. The identifier must be specified in standard ascii notation of
184 IPv6 addresses (e.g. ::dead:beef). If the
185 \fIipv6cp-use-ipaddr\fR
186 option is given, the local identifier is the local IPv4 address (see above).
187 Otherwise the identifier is randomized.
189 .B active-filter \fIfilter-expression
190 Specifies a packet filter to be applied to data packets to determine
191 which packets are to be regarded as link activity, and therefore reset
192 the idle timer, or cause the link to be brought up in demand-dialling
193 mode. This option is useful in conjunction with the
194 \fBidle\fR option if there are packets being sent or received
195 regularly over the link (for example, routing information packets)
196 which would otherwise prevent the link from ever appearing to be idle.
197 The \fIfilter-expression\fR syntax is as described for tcpdump(1),
198 except that qualifiers which are inappropriate for a PPP link, such as
199 \fBether\fR and \fBarp\fR, are not permitted. Generally the filter
200 expression should be enclosed in single-quotes to prevent whitespace
201 in the expression from being interpreted by the shell. This option
202 is currently only available under NetBSD, and then only
203 if both the kernel and pppd were compiled with PPP_FILTER defined.
206 Request that the peer compress packets that it sends, using the
207 BSD-Compress scheme, with a maximum code size of \fInr\fR bits, and
208 agree to compress packets sent to the peer with a maximum code size of
209 \fInt\fR bits. If \fInt\fR is not specified, it defaults to the value
210 given for \fInr\fR. Values in the range 9 to 15 may be used for
211 \fInr\fR and \fInt\fR; larger values give better compression but
212 consume more kernel memory for compression dictionaries.
213 Alternatively, a value of 0 for \fInr\fR or \fInt\fR disables
214 compression in the corresponding direction. Use \fInobsdcomp\fR or
215 \fIbsdcomp 0\fR to disable BSD-Compress compression entirely.
217 .B chap-interval \fIn
218 If this option is given, pppd will rechallenge the peer every \fIn\fR
221 .B chap-max-challenge \fIn
222 Set the maximum number of CHAP challenge transmissions to \fIn\fR
226 Set the CHAP restart interval (retransmission timeout for challenges)
227 to \fIn\fR seconds (default 3).
230 Enables connection debugging facilities.
231 If this option is given, pppd will log the contents of all
232 control packets sent or received in a readable form. The packets are
233 logged through syslog with facility \fIdaemon\fR and level
234 \fIdebug\fR. This information can be directed to a file by setting up
235 /etc/syslog.conf appropriately (see syslog.conf(5)).
238 Disable asyncmap negotiation, forcing all control characters to be
239 escaped for both the transmit and the receive direction.
242 Disable MRU [Maximum Receive Unit] negotiation. With this option,
243 pppd will use the default MRU value of 1500 bytes for both the
244 transmit and receive direction.
247 Request that the peer compress packets that it sends, using the
248 Deflate scheme, with a maximum window size of \fI2**nr\fR bytes, and
249 agree to compress packets sent to the peer with a maximum window size
250 of \fI2**nt\fR bytes. If \fInt\fR is not specified, it defaults to
251 the value given for \fInr\fR. Values in the range 8 to 15 may be used
252 for \fInr\fR and \fInt\fR; larger values give better compression but
253 consume more kernel memory for compression dictionaries.
254 Alternatively, a value of 0 for \fInr\fR or \fInt\fR disables
255 compression in the corresponding direction. Use \fInodeflate\fR or
256 \fIdeflate 0\fR to disable Deflate compression entirely. (Note: pppd
257 requests Deflate compression in preference to BSD-Compress if the peer
261 Initiate the link only on demand, i.e. when data traffic is present.
262 With this option, the remote IP address must be specified by the user
263 on the command line or in an options file. Pppd will initially
264 configure the interface and enable it for IP traffic without
265 connecting to the peer. When traffic is available, pppd will
266 connect to the peer and perform negotiation, authentication, etc.
267 When this is completed, pppd will commence passing data packets
268 (i.e., IP packets) across the link.
270 The \fIdemand\fR option implies the \fIpersist\fR option. If this
271 behaviour is not desired, use the \fInopersist\fR option after the
272 \fIdemand\fR option. The \fIidle\fR and \fIholdoff\fR
273 options are also useful in conjuction with the \fIdemand\fR option.
276 Append the domain name \fId\fR to the local host name for authentication
277 purposes. For example, if gethostname() returns the name porsche, but
278 the fully qualified domain name is porsche.Quotron.COM, you could
279 specify \fIdomain Quotron.COM\fR. Pppd would then use the name
280 \fIporsche.Quotron.COM\fR for looking up secrets in the secrets file,
281 and as the default name to send to the peer when authenticating itself
282 to the peer. This option is privileged.
285 When logging the contents of PAP packets, this option causes pppd to
286 exclude the password string from the log.
289 Specifies how many seconds to wait before re-initiating the link after
290 it terminates. This option only has any effect if the \fIpersist\fR
291 or \fIdemand\fR option is used. The holdoff period is not applied if
292 the link was terminated because it was idle.
295 Specifies that pppd should disconnect if the link is idle for \fIn\fR
296 seconds. The link is idle when no data packets (i.e. IP packets) are
297 being sent or received. Note: it is not advisable to use this option
298 with the \fIpersist\fR option without the \fIdemand\fR option.
299 If the \fBactive-filter\fR
300 option is given, data packets which are rejected by the specified
301 activity filter also count as the link being idle.
304 With this option, pppd will accept the peer's idea of our local IP
305 address, even if the local IP address was specified in an option.
307 .B ipcp-accept-remote
308 With this option, pppd will accept the peer's idea of its (remote) IP
309 address, even if the remote IP address was specified in an option.
311 .B ipcp-max-configure \fIn
312 Set the maximum number of IPCP configure-request transmissions to
313 \fIn\fR (default 10).
315 .B ipcp-max-failure \fIn
316 Set the maximum number of IPCP configure-NAKs returned before starting
317 to send configure-Rejects instead to \fIn\fR (default 10).
319 .B ipcp-max-terminate \fIn
320 Set the maximum number of IPCP terminate-request transmissions to
324 Set the IPCP restart interval (retransmission timeout) to \fIn\fR
328 Provides an extra parameter to the ip-up and ip-down scripts. If this
329 option is given, the \fIstring\fR supplied is given as the 6th
330 parameter to those scripts.
332 .B ipv6cp-max-configure \fIn
333 Set the maximum number of IPv6CP configure-request transmissions to
334 \fIn\fR (default 10).
336 .B ipv6cp-max-failure \fIn
337 Set the maximum number of IPv6CP configure-NAKs returned before starting
338 to send configure-Rejects instead to \fIn\fR (default 10).
340 .B ipv6cp-max-terminate \fIn
341 Set the maximum number of IPv6CP terminate-request transmissions to
344 .B ipv6cp-restart \fIn
345 Set the IPv6CP restart interval (retransmission timeout) to \fIn\fR
349 Enable the IPXCP and IPX protocols. This option is presently only
350 supported under Linux, and only if your kernel has been configured to
354 Set the IPX network number in the IPXCP configure request frame to
355 \fIn\fR, a hexadecimal number (without a leading 0x). There is no
356 valid default. If this option is not specified, the network number is
357 obtained from the peer. If the peer does not have the network number,
358 the IPX protocol will not be started.
360 .B ipx-node \fIn\fB:\fIm
361 Set the IPX node numbers. The two node numbers are separated from each
362 other with a colon character. The first number \fIn\fR is the local
363 node number. The second number \fIm\fR is the peer's node number. Each
364 node number is a hexadecimal number, at most 10 digits long. The node
365 numbers on the ipx-network must be unique. There is no valid
366 default. If this option is not specified then the node numbers are
367 obtained from the peer.
369 .B ipx-router-name \fI<string>
370 Set the name of the router. This is a string and is sent to the peer
374 Set the routing protocol to be received by this option. More than one
375 instance of \fIipx-routing\fR may be specified. The '\fInone\fR'
376 option (0) may be specified as the only instance of ipx-routing. The
377 values may be \fI0\fR for \fINONE\fR, \fI2\fR for \fIRIP/SAP\fR, and
378 \fI4\fR for \fINLSP\fR.
380 .B ipxcp-accept-local
381 Accept the peer's NAK for the node number specified in the ipx-node
382 option. If a node number was specified, and non-zero, the default is
383 to insist that the value be used. If you include this option then you
384 will permit the peer to override the entry of the node number.
386 .B ipxcp-accept-network
387 Accept the peer's NAK for the network number specified in the
388 ipx-network option. If a network number was specified, and non-zero, the
389 default is to insist that the value be used. If you include this
390 option then you will permit the peer to override the entry of the node
393 .B ipxcp-accept-remote
394 Use the peer's network number specified in the configure request
395 frame. If a node number was specified for the peer and this option was
396 not specified, the peer will be forced to use the value which you have
399 .B ipxcp-max-configure \fIn
400 Set the maximum number of IPXCP configure request frames which the
401 system will send to \fIn\fR. The default is 10.
403 .B ipxcp-max-failure \fIn
404 Set the maximum number of IPXCP NAK frames which the local system will
405 send before it rejects the options. The default value is 3.
407 .B ipxcp-max-terminate \fIn
408 Set the maximum nuber of IPXCP terminate request frames before the
409 local system considers that the peer is not listening to them. The
413 Enable debugging code in the kernel-level PPP driver. The argument
414 \fIn\fR is a number which is the sum of the following values: 1 to
415 enable general debug messages, 2 to request that the contents of
416 received packets be printed, and 4 to request that the contents of
417 transmitted packets be printed. On most systems, messages printed by
418 the kernel are logged by syslog(1) to a file as directed in the
419 /etc/syslog.conf configuration file.
421 .B lcp-echo-failure \fIn
422 If this option is given, pppd will presume the peer to be dead
423 if \fIn\fR LCP echo-requests are sent without receiving a valid LCP
424 echo-reply. If this happens, pppd will terminate the
425 connection. Use of this option requires a non-zero value for the
426 \fIlcp-echo-interval\fR parameter. This option can be used to enable
427 pppd to terminate after the physical connection has been broken
428 (e.g., the modem has hung up) in situations where no hardware modem
429 control lines are available.
431 .B lcp-echo-interval \fIn
432 If this option is given, pppd will send an LCP echo-request frame to
433 the peer every \fIn\fR seconds. Normally the peer should respond to
434 the echo-request by sending an echo-reply. This option can be used
435 with the \fIlcp-echo-failure\fR option to detect that the peer is no
438 .B lcp-max-configure \fIn
439 Set the maximum number of LCP configure-request transmissions to
440 \fIn\fR (default 10).
442 .B lcp-max-failure \fIn
443 Set the maximum number of LCP configure-NAKs returned before starting
444 to send configure-Rejects instead to \fIn\fR (default 10).
446 .B lcp-max-terminate \fIn
447 Set the maximum number of LCP terminate-request transmissions to
451 Set the LCP restart interval (retransmission timeout) to \fIn\fR
454 .B linkname \fIname\fR
455 Sets the logical name of the link to \fIname\fR. Pppd will create a
456 file named \fBppp-\fIname\fB.pid\fR in /var/run (or /etc/ppp on some
457 systems) containing its process ID. This can be useful in determining
458 which instance of pppd is responsible for the link to a given peer
459 system. This is a privileged option.
462 Don't use the modem control lines. With this option, pppd will ignore
463 the state of the CD (Carrier Detect) signal from the modem and will
464 not change the state of the DTR (Data Terminal Ready) signal.
467 Send log messages to file descriptor \fIn\fR. Pppd will send log
468 messages to at most one file or file descriptor (as well as sending
469 the log messages to syslog), so this option and the \fBlogfile\fR
470 option are mutually exclusive. The default is for pppd to send log
471 messages to stdout (file descriptor 1), unless the serial port is
472 already open on stdout.
474 .B logfile \fIfilename
475 Append log messages to the file \fIfilename\fR (as well as sending the
476 log messages to syslog). The file is opened with the privileges of
477 the user who invoked pppd, in append mode.
480 Use the system password database for authenticating the peer using
481 PAP, and record the user in the system wtmp file. Note that the peer
482 must have an entry in the /etc/ppp/pap-secrets file as well as the
483 system password database to be allowed access.
486 Terminate the connection when it has been available for network
487 traffic for \fIn\fR seconds (i.e. \fIn\fR seconds after the first
488 network control protocol comes up).
491 Terminate after \fIn\fR consecutive failed connection attempts. A
492 value of 0 means no limit. The default value is 10.
495 Use the modem control lines. This option is the default. With this
496 option, pppd will wait for the CD (Carrier Detect) signal from the
497 modem to be asserted when opening the serial device (unless a connect
498 script is specified), and it will drop the DTR (Data Terminal Ready)
499 signal briefly when the connection is terminated and before executing
500 the connect script. On Ultrix, this option implies hardware flow
501 control, as for the \fIcrtscts\fR option.
504 If pppd is acting as a server for Microsoft Windows clients, this
505 option allows pppd to supply one or two DNS (Domain Name Server)
506 addresses to the clients. The first instance of this option specifies
507 the primary DNS address; the second instance (if given) specifies the
508 secondary DNS address. (This option was present in some older
509 versions of pppd under the name \fBdns-addr\fR.)
512 If pppd is acting as a server for Microsoft Windows or "Samba"
513 clients, this option allows pppd to supply one or two WINS (Windows
514 Internet Name Services) server addresses to the clients. The first
515 instance of this option specifies the primary WINS address; the second
516 instance (if given) specifies the secondary WINS address.
519 Set the name of the local system for authentication purposes to
520 \fIname\fR. This is a privileged option. With this option, pppd will
521 use lines in the secrets files which have \fIname\fR as the second
522 field when looking for a secret to use in authenticating the peer. In
523 addition, unless overridden with the \fIuser\fR option, \fIname\fR
524 will be used as the name to send to the peer when authenticating the
525 local system to the peer. (Note that pppd does not append the domain
529 Set the interface netmask to \fIn\fR, a 32 bit netmask in "decimal dot"
530 notation (e.g. 255.255.255.0). If this option is given, the value
531 specified is ORed with the default netmask. The default netmask is
532 chosen based on the negotiated remote IP address; it is the
533 appropriate network mask for the class of the remote IP address, ORed
534 with the netmasks for any non point-to-point network interfaces in the
535 system which are on the same network. (Note: on some platforms, pppd
536 will always use 255.255.255.255 for the netmask, if that is the only
537 appropriate value for a point-to-point interface.)
540 Disable Address/Control compression in both directions (send and
544 Do not require the peer to authenticate itself. This option is
548 Disables BSD-Compress compression; \fBpppd\fR will not request or
549 agree to compress packets using the BSD-Compress scheme.
552 Disable CCP (Compression Control Protocol) negotiation. This option
553 should only be required if the peer is buggy and gets confused by
554 requests from pppd for CCP negotiation.
557 Disable hardware flow control (i.e. RTS/CTS) on the serial port.
558 If neither the \fIcrtscts\fR nor the \fInocrtscts\fR nor the
559 \fIcdtrcts\fR nor the \fInodtrcts\fR option is given, the hardware
560 flow control setting for the serial port is left unchanged.
563 This option is a synonym for \fInocrtscts\fR. Either of these options will
564 disable both forms of hardware flow control.
567 Disable the \fIdefaultroute\fR option. The system administrator who
568 wishes to prevent users from creating default routes with pppd
569 can do so by placing this option in the /etc/ppp/options file.
572 Disables Deflate compression; pppd will not request or agree to
573 compress packets using the Deflate scheme.
576 Don't detach from the controlling terminal. Without this option, if a
577 serial device other than the terminal on the standard input is
578 specified, pppd will fork to become a background process.
581 Disable IPCP negotiation and IP communication. This option should
582 only be required if the peer is buggy and gets confused by requests
583 from pppd for IPCP negotiation.
586 Disable IPv6CP negotiation and IPv6 communication. This option should
587 only be required if the peer is buggy and gets confused by requests
588 from pppd for IPv6CP negotiation.
591 Disables the default behaviour when no local IP address is specified,
592 which is to determine (if possible) the local IP address from the
593 hostname. With this option, the peer will have to supply the local IP
594 address during IPCP negotiation (unless it specified explicitly on the
595 command line or in an options file).
598 Disable the IPXCP and IPX protocols. This option should only be
599 required if the peer is buggy and gets confused by requests from pppd
600 for IPXCP negotiation.
603 Do not send log messages to a file or file descriptor. This option
604 cancels the \fBlogfd\fR and \fBlogfile\fR options.
606 Disable magic number negotiation. With this option, pppd cannot
607 detect a looped-back line. This option should only be needed if the
611 Disable protocol field compression negotiation in both the receive and
612 the transmit direction.
615 Exit once a connection has been made and terminated. This is the
616 default unless the \fIpersist\fR or \fIdemand\fR option has been
620 Do not accept or agree to Predictor-1 compression.
623 Disable the \fIproxyarp\fR option. The system administrator who
624 wishes to prevent users from creating proxy ARP entries with pppd can
625 do so by placing this option in the /etc/ppp/options file.
628 Normally, pppd requires a terminal device. With this option, pppd
629 will allocate itself a pseudo-tty master/slave pair and use the slave
630 as its terminal device. Pppd will create a child process to act as a
631 `character shunt' to transfer characters between the pseudo-tty master
632 and its standard input and output. Thus pppd will transmit characters
633 on its standard output and receive characters on its standard input
634 even if they are not terminal devices. This option increases the
635 latency and CPU overhead of transferring data over the ppp interface
636 as all of the characters sent and received must flow through the
637 character shunt process. An explicit device name may not be given if
641 Disable Van Jacobson style TCP/IP header compression in both the
642 transmit and the receive direction.
645 Disable the connection-ID compression option in Van Jacobson style
646 TCP/IP header compression. With this option, pppd will not omit the
647 connection-ID byte from Van Jacobson compressed TCP/IP headers, nor
648 ask the peer to do so.
651 Indicates that all secrets in the /etc/ppp/pap-secrets file which are
652 used for checking the identity of the peer are encrypted, and thus
653 pppd should not accept a password which, before encryption, is
654 identical to the secret from the /etc/ppp/pap-secrets file.
656 .B pap-max-authreq \fIn
657 Set the maximum number of PAP authenticate-request transmissions to
658 \fIn\fR (default 10).
661 Set the PAP restart interval (retransmission timeout) to \fIn\fR
665 Set the maximum time that pppd will wait for the peer to authenticate
666 itself with PAP to \fIn\fR seconds (0 means no limit).
668 .B pass-filter \fIfilter-expression
669 Specifies a packet filter to applied to data packets being sent or
670 received to determine which packets should be allowed to pass.
671 Packets which are rejected by the filter are silently discarded. This
672 option can be used to prevent specific network daemons (such as
673 routed) using up link bandwidth, or to provide a basic firewall
675 The \fIfilter-expression\fR syntax is as described for tcpdump(1),
676 except that qualifiers which are inappropriate for a PPP link, such as
677 \fBether\fR and \fBarp\fR, are not permitted. Generally the filter
678 expression should be enclosed in single-quotes to prevent whitespace
679 in the expression from being interpreted by the shell. Note that it
680 is possible to apply different constraints to incoming and outgoing
681 packets using the \fBinbound\fR and \fBoutbound\fR qualifiers. This
682 option is currently only available under NetBSD, and then only if both
683 the kernel and pppd were compiled with PPP_FILTER defined.
686 Do not exit after a connection is terminated; instead try to reopen
690 Request that the peer compress frames that it sends using Predictor-1
691 compression, and agree to compress transmitted frames with Predictor-1
692 if requested. This option has no effect unless the kernel driver
693 supports Predictor-1 compression.
695 .B privgroup \fIgroup-name
696 Allows members of group \fIgroup-name\fR to use privileged options.
697 This is a privileged option. Use of this option requires care as
698 there is no guarantee that members of \fIgroup-name\fR cannot use pppd
699 to become root themselves. Consider it equivalent to putting the
700 members of \fIgroup-name\fR in the kmem or disk group.
703 Add an entry to this system's ARP [Address Resolution Protocol] table
704 with the IP address of the peer and the Ethernet address of this
705 system. This will have the effect of making the peer appear to other
706 systems to be on the local ethernet.
709 Specifies that the command \fIscript\fR is to be used to communicate
710 rather than a specific terminal device. Pppd will allocate itself a
711 pseudo-tty master/slave pair and use the slave as its terminal
712 device. The \fIscript\fR will be run in a child process with the
713 pseudo-tty master as its standard input and output. An explicit
714 device name may not be given if this option is used.
717 With this option, pppd will accept all control characters from the
718 peer, including those marked in the receive asyncmap. Without this
719 option, pppd will discard those characters as specified in RFC1662.
720 This option should only be needed if the peer is buggy.
722 .B record \fIfilename
723 Specifies that pppd should record all characters sent and received to
724 a file named \fIfilename\fR. This file is opened in append mode,
725 using the user's user-ID and permissions. This option is implemented
726 using a pseudo-tty and a process to transfer characters between the
727 pseudo-tty and the real serial device, so it will increase the latency
728 and CPU overhead of transferring data over the ppp interface. The
729 characters are stored in a tagged format with timestamps, which can be
730 displayed in readable form using the pppdump(8) program.
732 .B remotename \fIname
733 Set the assumed name of the remote system for authentication purposes
737 With this option, pppd will not agree to authenticate itself to the
741 With this option, pppd will not agree to authenticate itself to the
745 Require the peer to authenticate itself using CHAP [Challenge
746 Handshake Authentication Protocol] authentication.
749 Require the peer to authenticate itself using PAP [Password
750 Authentication Protocol] authentication.
753 With this option, pppd will not transmit LCP packets to initiate a
754 connection until a valid LCP packet is received from the peer (as for
755 the `passive' option with ancient versions of pppd).
758 Use synchronous HDLC serial encoding instead of asynchronous.
759 The device used by pppd with this option must have sync support.
760 Currently supports Microgate SyncLink adapters
761 under Linux and FreeBSD 2.2.8 and later.
764 With this option, pppd will detach from its controlling terminal once
765 it has successfully established the ppp connection (to the point where
766 the first network control protocol, usually the IP control protocol,
770 Enforce the use of the hostname (with domain name appended, if given)
771 as the name of the local system for authentication purposes (overrides
772 the \fIname\fR option). This option is not normally needed since the
773 \fIname\fR option is privileged.
776 Ask the peer for up to 2 DNS server addresses. The addresses supplied
777 by the peer (if any) are passed to the /etc/ppp/ip-up script in the
778 environment variables DNS1 and DNS2.
781 Sets the name used for authenticating the local system to the peer to
785 Sets the number of connection slots to be used by the Van Jacobson
786 TCP/IP header compression and decompression code to \fIn\fR, which
787 must be between 2 and 16 (inclusive).
790 Run the executable or shell command specified by \fIscript\fR before
791 initiating PPP negotiation, after the connect script (if any) has
792 completed. A value for this option from a privileged source cannot be
793 overridden by a non-privileged user.
796 Use software flow control (i.e. XON/XOFF) to control the flow of data on
799 Options can be taken from files as well as the command line. Pppd
800 reads options from the files /etc/ppp/options, ~/.ppprc and
801 /etc/ppp/options.\fIttyname\fR (in that order) before processing the
802 options on the command line. (In fact, the command-line options are
803 scanned to find the terminal name before the options.\fIttyname\fR
804 file is read.) In forming the name of the options.\fIttyname\fR file,
805 the initial /dev/ is removed from the terminal name, and any remaining
806 / characters are replaced with dots.
808 An options file is parsed into a series of words, delimited by
809 whitespace. Whitespace can be included in a word by enclosing the
810 word in double-quotes ("). A backslash (\\) quotes the following character.
811 A hash (#) starts a comment, which continues until the end of the
812 line. There is no restriction on using the \fIfile\fR or \fIcall\fR
813 options within an options file.
816 provides system administrators with sufficient access control that PPP
817 access to a server machine can be provided to legitimate users without
818 fear of compromising the security of the server or the network it's
819 on. This control is provided through restrictions on which IP
820 addresses the peer may use, based on its authenticated identity (if
821 any), and through restrictions on which options a non-privileged user
822 may use. Several of pppd's options are privileged, in particular
823 those which permit potentially insecure configurations; these options
824 are only accepted in files which are under the control of the system
825 administrator, or if pppd is being run by root.
827 The default behaviour of pppd is to allow an unauthenticated peer to
828 use a given IP address only if the system does not already have a
829 route to that IP address. For example, a system with a
830 permanent connection to the wider internet will normally have a
831 default route, and thus all peers will have to authenticate themselves
832 in order to set up a connection. On such a system, the \fIauth\fR
833 option is the default. On the other hand, a system where the
834 PPP link is the only connection to the internet will not normally have
835 a default route, so the peer will be able to use almost any IP address
836 without authenticating itself.
838 As indicated above, some security-sensitive options are privileged,
839 which means that they may not be used by an ordinary non-privileged
840 user running a setuid-root pppd, either on the command line, in the
841 user's ~/.ppprc file, or in an options file read using the \fIfile\fR
842 option. Privileged options may be used in /etc/ppp/options file or in
843 an options file read using the \fIcall\fR option. If pppd is being
844 run by the root user, privileged options can be used without
847 When opening the device, pppd uses either the invoking user's user ID
848 or the root UID (that is, 0), depending on whether the device name was
849 specified by the user or the system administrator. If the device name
850 comes from a privileged source, that is, /etc/ppp/options or an
851 options file read using the \fIcall\fR option, pppd uses full root
852 privileges when opening the device. Thus, by creating an appropriate
853 file under /etc/ppp/peers, the system administrator can allow users to
854 establish a ppp connection via a device which they would not normally
855 have permission to access. Otherwise pppd uses the invoking user's
856 real UID when opening the device.
858 Authentication is the process whereby one peer convinces the other of
859 its identity. This involves the first peer sending its name to the
860 other, together with some kind of secret information which could only
861 come from the genuine authorized user of that name. In such an
862 exchange, we will call the first peer the "client" and the other the
863 "server". The client has a name by which it identifies itself to the
864 server, and the server also has a name by which it identifies itself
865 to the client. Generally the genuine client shares some secret (or
866 password) with the server, and authenticates itself by proving that it
867 knows that secret. Very often, the names used for authentication
868 correspond to the internet hostnames of the peers, but this is not
871 At present, pppd supports two authentication protocols: the Password
872 Authentication Protocol (PAP) and the Challenge Handshake
873 Authentication Protocol (CHAP). PAP involves the client sending its
874 name and a cleartext password to the server to authenticate itself.
875 In contrast, the server initiates the CHAP authentication exchange by
876 sending a challenge to the client (the challenge packet includes the
877 server's name). The client must respond with a response which
878 includes its name plus a hash value derived from the shared secret and
879 the challenge, in order to prove that it knows the secret.
881 The PPP protocol, being symmetrical, allows both peers to require the
882 other to authenticate itself. In that case, two separate and
883 independent authentication exchanges will occur. The two exchanges
884 could use different authentication protocols, and in principle,
885 different names could be used in the two exchanges.
887 The default behaviour of pppd is to agree to authenticate if
888 requested, and to not require authentication from the peer. However,
889 pppd will not agree to authenticate itself with a particular protocol
890 if it has no secrets which could be used to do so.
892 Pppd stores secrets for use in authentication in secrets
893 files (/etc/ppp/pap-secrets for PAP, /etc/ppp/chap-secrets for CHAP).
894 Both secrets files have the same format. The secrets files can
895 contain secrets for pppd to use in authenticating itself to other
896 systems, as well as secrets for pppd to use when authenticating other
899 Each line in a secrets file contains one secret. A given secret is
900 specific to a particular combination of client and server - it can
901 only be used by that client to authenticate itself to that server.
902 Thus each line in a secrets file has at least 3 fields: the name of
903 the client, the name of the server, and the secret. These fields may
904 be followed by a list of the IP addresses that the specified client
905 may use when connecting to the specified server.
907 A secrets file is parsed into words as for a options file, so the
908 client name, server name and secrets fields must each be one word,
909 with any embedded spaces or other special characters quoted or
910 escaped. Any following words on the same line are taken to be a list
911 of acceptable IP addresses for that client. If there are only 3 words
912 on the line, or if the first word is "-", then all IP addresses are
913 disallowed. To allow any address, use "*".
914 A word starting with "!" indicates that the
915 specified address is \fInot\fR acceptable. An address may be followed
916 by "/" and a number \fIn\fR, to indicate a whole subnet, i.e. all
917 addresses which have the same value in the most significant \fIn\fR
918 bits. Note that case is significant in the client and server names
921 If the secret starts with an `@', what follows is assumed to be the
922 name of a file from which to read the secret. A "*" as the client or
923 server name matches any name. When selecting a secret, pppd takes the
924 best match, i.e. the match with the fewest wildcards.
926 Thus a secrets file contains both secrets for use in authenticating
927 other hosts, plus secrets which we use for authenticating ourselves to
928 others. When pppd is authenticating the peer (checking the peer's
929 identity), it chooses a secret with the peer's name in the first
930 field and the name of the local system in the second field. The
931 name of the local system defaults to the hostname, with the domain
932 name appended if the \fIdomain\fR option is used. This default can be
933 overridden with the \fIname\fR option, except when the
934 \fIusehostname\fR option is used.
936 When pppd is choosing a secret to use in authenticating itself to the
937 peer, it first determines what name it is going to use to identify
938 itself to the peer. This name can be specified by the user with the
939 \fIuser\fR option. If this option is not used, the name defaults to
940 the name of the local system, determined as described in the previous
941 paragraph. Then pppd looks for a secret with this name in the first
942 field and the peer's name in the second field. Pppd will know the
943 name of the peer if CHAP authentication is being used, because the
944 peer will have sent it in the challenge packet. However, if PAP is being
945 used, pppd will have to determine the peer's name from the options
946 specified by the user. The user can specify the peer's name directly
947 with the \fIremotename\fR option. Otherwise, if the remote IP address
948 was specified by a name (rather than in numeric form), that name will
949 be used as the peer's name. Failing that, pppd will use the null
950 string as the peer's name.
952 When authenticating the peer with PAP, the supplied password is first
953 compared with the secret from the secrets file. If the password
954 doesn't match the secret, the password is encrypted using crypt() and
955 checked against the secret again. Thus secrets for authenticating the
956 peer can be stored in encrypted form if desired. If the
957 \fIpapcrypt\fR option is given, the first (unencrypted) comparison is
958 omitted, for better security.
960 Furthermore, if the \fIlogin\fR option was specified, the username and
961 password are also checked against the system password database. Thus,
962 the system administrator can set up the pap-secrets file to allow PPP
963 access only to certain users, and to restrict the set of IP addresses
964 that each user can use. Typically, when using the \fIlogin\fR option,
965 the secret in /etc/ppp/pap-secrets would be "", which will match any
966 password supplied by the peer. This avoids the need to have the same
967 secret in two places.
969 Authentication must be satisfactorily completed before IPCP (or any
970 other Network Control Protocol) can be started. If the peer is
971 required to authenticate itself, and fails to do so, pppd will
972 terminated the link (by closing LCP). If IPCP negotiates an
973 unacceptable IP address for the remote host, IPCP will be closed. IP
974 packets can only be sent or received when IPCP is open.
976 In some cases it is desirable to allow some hosts which can't
977 authenticate themselves to connect and use one of a restricted set of
978 IP addresses, even when the local host generally requires
979 authentication. If the peer refuses to authenticate itself when
980 requested, pppd takes that as equivalent to authenticating with PAP
981 using the empty string for the username and password. Thus, by adding
982 a line to the pap-secrets file which specifies the empty string for
983 the client and password, it is possible to allow restricted access to
984 hosts which refuse to authenticate themselves.
987 When IPCP negotiation is completed successfully, pppd will inform the
988 kernel of the local and remote IP addresses for the ppp interface.
989 This is sufficient to create a host route to the remote end of the
990 link, which will enable the peers to exchange IP packets.
991 Communication with other machines generally requires further
992 modification to routing tables and/or ARP (Address Resolution
993 Protocol) tables. In most cases the \fIdefaultroute\fR and/or
994 \fIproxyarp\fR options are sufficient for this, but in some cases
995 further intervention is required. The /etc/ppp/ip-up script can be
998 Sometimes it is desirable to add a default route through the remote
999 host, as in the case of a machine whose only connection to the
1000 Internet is through the ppp interface. The \fIdefaultroute\fR option
1001 causes pppd to create such a default route when IPCP comes up, and
1002 delete it when the link is terminated.
1004 In some cases it is desirable to use proxy ARP, for example on a
1005 server machine connected to a LAN, in order to allow other hosts to
1006 communicate with the remote host. The \fIproxyarp\fR option causes
1007 pppd to look for a network interface on the same subnet as the remote
1008 host (an interface supporting broadcast and ARP, which is up and not a
1009 point-to-point or loopback interface). If found, pppd creates a
1010 permanent, published ARP entry with the IP address of the remote host
1011 and the hardware address of the network interface found.
1013 When the \fIdemand\fR option is used, the interface IP addresses have
1014 already been set at the point when IPCP comes up. If pppd has not
1015 been able to negotiate the same addresses that it used to configure
1016 the interface (for example when the peer is an ISP that uses dynamic
1017 IP address assignment), pppd has to change the interface IP addresses
1018 to the negotiated addresses. This may disrupt existing connections,
1019 and the use of demand dialling with peers that do dynamic IP address
1020 assignment is not recommended.
1023 The following examples assume that the /etc/ppp/options file contains
1024 the \fIauth\fR option (as in the default /etc/ppp/options file in the
1027 Probably the most common use of pppd is to dial out to an ISP. This
1028 can be done with a command such as
1032 where the /etc/ppp/peers/isp file is set up by the system
1033 administrator to contain something like this:
1037 connect '/usr/sbin/chat -v -f /etc/ppp/chat-isp'
1041 In this example, we are using chat to dial the ISP's modem and go
1042 through any logon sequence required. The /etc/ppp/chat-isp file
1043 contains the script used by chat; it could for example contain
1044 something like this:
1056 ABORT "Username/Password Incorrect"
1064 "name:" "^Umyuserid"
1066 "word:" "\\qmypassword"
1072 See the chat(8) man page for details of chat scripts.
1074 Pppd can also be used to provide a dial-in ppp service for users. If
1075 the users already have login accounts, the simplest way to set up the
1076 ppp service is to let the users log in to their accounts and run pppd
1077 (installed setuid-root) with a command such as
1081 To allow a user to use the PPP facilities, you need to allocate an IP
1082 address for that user's machine and create an entry in
1083 /etc/ppp/pap-secrets or /etc/ppp/chap-secrets (depending on which
1084 authentication method the PPP implementation on the user's machine
1085 supports), so that the user's
1086 machine can authenticate itself. For example, if Joe has a machine
1087 called "joespc" which is to be allowed to dial in to the machine
1088 called "server" and use the IP address joespc.my.net, you would add an
1089 entry like this to /etc/ppp/pap-secrets or /etc/ppp/chap-secrets:
1091 joespc server "joe's secret" joespc.my.net
1093 Alternatively, you can create a username called (for example) "ppp",
1094 whose login shell is pppd and whose home directory is /etc/ppp.
1095 Options to be used when pppd is run this way can be put in
1098 If your serial connection is any more complicated than a piece of
1099 wire, you may need to arrange for some control characters to be
1100 escaped. In particular, it is often useful to escape XON (^Q) and
1101 XOFF (^S), using \fIasyncmap a0000\fR. If the path includes a telnet,
1102 you probably should escape ^] as well (\fIasyncmap 200a0000\fR). If
1103 the path includes an rlogin, you will need to use the \fIescape ff\fR
1104 option on the end which is running the rlogin client, since many
1105 rlogin implementations are not transparent; they will remove the
1106 sequence [0xff, 0xff, 0x73, 0x73, followed by any 8 bytes] from the
1110 Messages are sent to the syslog daemon using facility LOG_DAEMON.
1111 (This can be overriden by recompiling pppd with the macro
1112 LOG_PPP defined as the desired facility.) In order to see the error
1113 and debug messages, you will need to edit your /etc/syslog.conf file
1114 to direct the messages to the desired output device or file.
1116 The \fIdebug\fR option causes the contents of all control packets sent
1117 or received to be logged, that is, all LCP, PAP, CHAP or IPCP packets.
1118 This can be useful if the PPP negotiation does not succeed or if
1119 authentication fails.
1120 If debugging is enabled at compile time, the \fIdebug\fR option also
1121 causes other debugging messages to be logged.
1123 Debugging can also be enabled or disabled by sending a SIGUSR1 signal
1124 to the pppd process. This signal acts as a toggle.
1126 The exit status of pppd is set to indicate whether any error was
1127 detected, or the reason for the link being terminated. The values
1131 Pppd has detached, or otherwise the connection was successfully
1132 established and terminated at the peer's request.
1135 An immediately fatal error of some kind occurred, such as an essential
1136 system call failing, or running out of virtual memory.
1139 An error was detected in processing the options given, such as two
1140 mutually exclusive options being used.
1143 Pppd is not setuid-root and the invoking user is not root.
1146 The kernel does not support PPP, for example, the PPP kernel driver is
1147 not included or cannot be loaded.
1150 Pppd terminated because it was sent a SIGINT, SIGTERM or SIGHUP
1154 The serial port could not be locked.
1157 The serial port could not be opened.
1160 The connect script failed (returned a non-zero exit status).
1163 The command specified as the argument to the \fIpty\fR option could
1167 The PPP negotiation failed, that is, it didn't reach the point where
1168 at least one network protocol (e.g. IP) was running.
1171 The peer system failed (or refused) to authenticate itself.
1174 The link was established successfully and terminated because it was
1178 The link was established successfully and terminated because the
1179 connect time limit was reached.
1182 Callback was negotiated and an incoming call should arrive shortly.
1185 The link was terminated because the peer is not responding to echo
1189 The link was terminated by the modem hanging up.
1192 The PPP negotiation failed because serial loopback was detected.
1195 The init script failed (returned a non-zero exit status).
1198 We failed to authenticate ourselves to the peer.
1200 Pppd invokes scripts at various stages in its processing which can be
1201 used to perform site-specific ancillary processing. These scripts are
1202 usually shell scripts, but could be executable code files instead.
1203 Pppd does not wait for the scripts to finish. The scripts are
1204 executed as root (with the real and effective user-id set to 0), so
1205 that they can do things such as update routing tables or run
1206 privileged daemons. Be careful that the contents of these scripts do
1207 not compromise your system's security. Pppd runs the scripts with
1208 standard input, output and error redirected to /dev/null, and with an
1209 environment that is empty except for some environment variables that
1210 give information about the link. The environment variables that pppd
1214 The name of the serial tty device being used.
1217 The name of the network interface being used.
1220 The IP address for the local end of the link. This is only set when
1224 The IP address for the remote end of the link. This is only set when
1228 The authenticated name of the peer. This is only set if the peer
1229 authenticates itself.
1232 The baud rate of the tty device.
1235 The real user-id of the user who invoked pppd.
1238 The username of the real user-id that invoked pppd. This is always set.
1240 For the ip-down and auth-down scripts, pppd also sets the following
1241 variables giving statistics for the connection:
1244 The number of seconds from when the PPP negotiation started until the
1245 connection was terminated.
1248 The number of bytes sent (at the level of the serial port) during the
1252 The number of bytes received (at the level of the serial port) during
1256 The logical name of the link, set with the \fIlinkname\fR option.
1258 Pppd invokes the following scripts, if they exist. It is not an error
1259 if they don't exist.
1262 A program or script which is executed after the remote system
1263 successfully authenticates itself. It is executed with the parameters
1265 \fIinterface-name peer-name user-name tty-device speed\fR
1267 Note that this script is not executed if the peer doesn't authenticate
1268 itself, for example when the \fInoauth\fR option is used.
1270 .B /etc/ppp/auth-down
1271 A program or script which is executed when the link goes down, if
1272 /etc/ppp/auth-up was previously executed. It is executed in the same
1273 manner with the same parameters as /etc/ppp/auth-up.
1276 A program or script which is executed when the link is available for
1277 sending and receiving IP packets (that is, IPCP has come up). It is
1278 executed with the parameters
1280 \fIinterface-name tty-device speed local-IP-address
1281 remote-IP-address ipparam\fR
1284 A program or script which is executed when the link is no longer
1285 available for sending and receiving IP packets. This script can be
1286 used for undoing the effects of the /etc/ppp/ip-up script. It is
1287 invoked in the same manner and with the same parameters as the ip-up
1291 Like /etc/ppp/ip-up, except that it is executed when the link is available
1292 for sending and receiving IPv6 packets. It is executed with the parameters
1294 \fIinterface-name tty-device speed local-link-local-address
1295 remote-link-local-address ipparam\fR
1297 .B /etc/ppp/ipv6-down
1298 Similar to /etc/ppp/ip-down, but it is executed when IPv6 packets can no
1299 longer be transmitted on the link. It is executed with the same parameters
1300 as the ipv6-up script.
1303 A program or script which is executed when the link is available for
1304 sending and receiving IPX packets (that is, IPXCP has come up). It is
1305 executed with the parameters
1307 \fIinterface-name tty-device speed network-number local-IPX-node-address
1308 remote-IPX-node-address local-IPX-routing-protocol remote-IPX-routing-protocol
1309 local-IPX-router-name remote-IPX-router-name ipparam pppd-pid\fR
1311 The local-IPX-routing-protocol and remote-IPX-routing-protocol field
1312 may be one of the following:
1314 NONE to indicate that there is no routing protocol
1316 RIP to indicate that RIP/SAP should be used
1318 NLSP to indicate that Novell NLSP should be used
1320 RIP NLSP to indicate that both RIP/SAP and NLSP should be used
1322 .B /etc/ppp/ipx-down
1323 A program or script which is executed when the link is no longer
1324 available for sending and receiving IPX packets. This script can be
1325 used for undoing the effects of the /etc/ppp/ipx-up script. It is
1326 invoked in the same manner and with the same parameters as the ipx-up
1330 .B /var/run/ppp\fIn\fB.pid \fR(BSD or Linux), \fB/etc/ppp/ppp\fIn\fB.pid \fR(others)
1331 Process-ID for pppd process on ppp interface unit \fIn\fR.
1333 .B /var/run/ppp-\fIname\fB.pid \fR(BSD or Linux), \fB/etc/ppp/ppp-\fIname\fB.pid \fR(others)
1334 Process-ID for pppd process for logical link \fIname\fR (see the
1335 \fIlinkname\fR option).
1337 .B /etc/ppp/pap-secrets
1338 Usernames, passwords and IP addresses for PAP authentication. This
1339 file should be owned by root and not readable or writable by any other
1340 user. Pppd will log a warning if this is not the case.
1342 .B /etc/ppp/chap-secrets
1343 Names, secrets and IP addresses for CHAP authentication. As for
1344 /etc/ppp/pap-secrets, this file should be owned by root and not
1345 readable or writable by any other user. Pppd will log a warning if
1346 this is not the case.
1349 System default options for pppd, read before user default options or
1350 command-line options.
1353 User default options, read before /etc/ppp/options.\fIttyname\fR.
1355 .B /etc/ppp/options.\fIttyname
1356 System default options for the serial port being used, read after
1357 ~/.ppprc. In forming the \fIttyname\fR part of this
1358 filename, an initial /dev/ is stripped from the port name (if
1359 present), and any slashes in the remaining part are converted to
1363 A directory containing options files which may contain privileged
1364 options, even if pppd was invoked by a user other than root. The
1365 system administrator can create options files in this directory to
1366 permit non-privileged users to dial out without requiring the peer to
1367 authenticate, but only to certain trusted peers.
1372 \fICompressing TCP/IP headers for low-speed serial links.\fR
1377 .I The MD5 Message-Digest Algorithm.
1382 .I PPP Internet Protocol Control Protocol (IPCP).
1386 Lloyd, B.; Simpson, W.A.
1387 .I PPP authentication protocols.
1392 .I The Point\-to\-Point Protocol (PPP).
1397 .I PPP in HDLC-like Framing.
1402 .I IP Version 6 over PPP
1405 The following signals have the specified effect when sent to pppd.
1408 These signals cause pppd to terminate the link (by closing LCP),
1409 restore the serial device settings, and exit.
1412 This signal causes pppd to terminate the link, restore the serial
1413 device settings, and close the serial device. If the \fIpersist\fR or
1414 \fIdemand\fR option has been specified, pppd will try to reopen the
1415 serial device and start another connection (after the holdoff period).
1416 Otherwise pppd will exit. If this signal is received during the
1417 holdoff period, it causes pppd to end the holdoff period immediately.
1420 This signal toggles the state of the \fIdebug\fR option.
1423 This signal causes pppd to renegotiate compression. This can be
1424 useful to re-enable compression after it has been disabled as a result
1425 of a fatal decompression error. (Fatal decompression errors generally
1426 indicate a bug in one or other implementation.)
1429 Paul Mackerras (Paul.Mackerras@cs.anu.edu.au), based on earlier work by
projects / ppp.git / blob