xref: /freebsd/usr.sbin/ppp/ppp.8 (revision df7f5d4de4592a8948a25ce01e5bddfbb7ce39dc)
1.\" manual page [] for ppp 0.94 beta2 + alpha
2.\" $Id: ppp.8,v 1.25 1997/02/22 16:10:45 peter Exp $
3.Dd 20 September 1995
4.Os FreeBSD
5.Dt PPP 8
6.Sh NAME
7.Nm ppp
8.Nd
9Point to Point Protocol (aka iijppp)
10.Sh SYNOPSIS
11.Nm
12.Op Fl auto | background | ddial | direct | dedicated
13.Op Fl alias
14.Op Ar system
15.Sh DESCRIPTION
16This is a user process
17.Em PPP
18software package.  Normally,
19.Em PPP
20is implemented as a part of the kernel (e.g. as managed by pppd) and it's
21thus somewhat hard to debug and/or modify its behavior.  However, in this
22implementation
23.Em PPP
24is done as a user process with the help of the
25tunnel device driver (tun).
26
27.Sh Major Features
28
29.Bl -diag
30.It Provides interactive user interface.
31Using its command mode, the user can
32easily enter commands to establish the connection with the remote end, check
33the status of connection and close the connection.  All functions can
34also be optionally password protected for security.
35
36.It Supports both manual and automatic dialing.
37Interactive mode has a
38.Dq term
39command which enables you to talk to your modem directly.  When your
40modem is connected to the remote peer and it starts to talk
41.Em PPP
42, the
43.Em PPP
44software detects it and switches to packet
45mode automatically. Once you have determined the proper sequence for connecting
46with the remote host, you can write a chat script to define the necessary
47dialing and login procedure for later convenience.
48
49.It Supports on-demand dialup capability.
50By using auto mode,
51.Nm
52will act as a daemon and wait for a packet to be sent over the
53.Em PPP
54link.  When this happens, the daemon automatically dials and establishes the
55connection.
56
57In almost the same manner ddial mode (dedicated or demon dialing)
58also automatically dials and establishes the connection.  However, it
59differs in that it will dial the remote site any time it detects the
60link is down, even if there are no packets to be sent.  This mode is
61useful for full-time connections who worry less about line charges
62and more about being connected full time.
63
64.It Supports packet aliasing.
65Packet aliasing, more commonly known as masquerading, allows computers
66on a private, unregistered network to access the internet.  The
67.Em PPP
68host acts as a masquerading gateway.  IP addresses as well as TCP and
69UDP port numbers are aliased for outgoing packets and de-aliased for
70returning packets.
71
72.It Supports background PPP connections.
73In background mode, if
74.Nm
75successfully establishes the connection, it will become a daemon.
76Otherwise, it will exit with an error.
77
78.It Supports server-side PPP connections.
79Can act as server which accepts incoming
80.Em PPP
81connections.
82
83.It Supports PAP and CHAP authentication.
84
85.It Supports Proxy Arp.
86When
87.Em PPP
88is set up as server, you can also configure it to do proxy arp for your
89connection.
90
91.It Supports packet filtering.
92User can define four kinds of filters:
93.Em ifilter
94for incoming packets,
95.Em ofilter
96for outgoing packets,
97.Em dfilter
98to define a dialing trigger packet and
99.Em afilter
100for keeping a connection alive with the trigger packet.
101
102.It Tunnel driver supports bpf.
103The user can use
104.Xr tcpdump 1
105to check the packet flow over the
106.Em PPP
107link.
108
109.It Supports PPP over TCP capability.
110
111
112.It Supports IETF draft Predictor-1 compression.
113.Nm
114supports not only VJ-compression but also Predictor-1 compression.
115Normally, a modem has built-in compression (e.g. v42.bis) and the system
116may receive higher data rates from it as a result of such compression.
117While this is generally a good thing in most other situations, this
118higher speed data imposes a penalty on the system by increasing the
119number of serial interrupts the system has to process in talking to the
120modem and also increases latency.  Unlike VJ-compression, Predictor-1
121compression pre-compresses
122.Em all
123data flowing through the link, thus reducing overhead to a minimum.
124
125.It Supports Microsofts IPCP extentions.
126Name Server Addresses and NetBIOS Name Server Addresses can be negotiated
127with clients using the Microsoft
128.Em PPP
129stack (ie. Win95, WinNT)
130
131.It Runs under BSDI-1.1 and FreeBSD.
132
133.El
134
135
136Patches for NeXTSTEP 3.2 are also available on the net.
137
138.Sh GETTING STARTED
139
140When you first run
141.Nm
142you may need to deal with some initial configuration details.  First,
143your kernel should include a tunnel device (the default in FreeBSD 2.0.5
144and later). If it doesn't, you'll need to rebuild your kernel with the
145following line in your kernel configuration file:
146
147.Dl pseudo-device   tun             1
148
149You should set the numeric field to the maximum number of
150.Em PPP
151connections you wish to support.
152
153Second, check your
154.Pa /dev
155directory for the tunnel device entry
156.Pa /dev/tun0.
157If it doesn't exist, you can create it by running "MAKEDEV tun0"
158
159.Sh MANUAL DIALING
160
161%
162.Nm
163User Process PPP written by Toshiharu OHNO.
164
165* If you set your hostname and password in
166.Pa /etc/ppp/ppp.secret,
167you can't do
168anything except run the quit and help commands *
169
170ppp on "your hostname"> help
171  passwd  : Password for security
172  quit    : Quit the PPP program
173  help    : Display this message
174
175ppp on tama> pass <password>
176
177* "on" will change to "ON" if you specify the correct password. *
178
179ppp ON tama>
180
181* You can now specify the device name, speed and parity
182for your modem, and whether
183CTS/RTS signalling should be used (CTS/RTS is used by default).
184If your hardware does not provide CTS/RTS lines (as
185may happen when you are connected directly to certain ppp-capable
186terminal servers),
187.Nm
188will never send any output through the port; it
189waits for a signal which never comes.
190Thus, if you have a direct line and can't seem to make
191a connection, try turning ctsrts off: *
192
193
194ppp ON tama> set line /dev/cuaa0
195
196ppp ON tama> set speed 38400
197
198ppp ON tama> set parity even
199
200ppp ON tama> set ctsrts on
201
202ppp ON tama> show modem
203
204* Modem related parameters are shown in here *
205
206ppp ON tama>
207
208* Use term command to talk with your modem *
209
210ppp ON tama> term
211 at
212 OK
213 atdt123456
214 CONNECT
215
216 login: ppp
217 Password:
218
219* PPP started in remote side.  When the peer start to talk PPP, the
220program will detect it automatically and return to command mode. *
221
222ppp ON tama>
223
224.Nm PPP
225ON tama>
226
227* NOW, you are connected!  Note that
228.Sq PPP
229in the prompt has changed to capital letters to indicate this. *
230
231PPP ON tama> show lcp
232
233* You'll see LCP status *
234
235PPP ON tama> show ipcp
236
237* You'll see IPCP status.  At this point, your machine has a host route
238to the peer. If you want to add a default route entry, then enter the
239following command. *
240
241PPP ON tama> add 0 0 HISADDR
242
243* The string
244.Sq HISADDR
245represents the IP address of connected peer. *
246
247PPP ON tama>
248
249* Use network applications (i.e. ping, telnet, ftp) in other windows *
250
251PPP ON tama> show log
252
253* Gives you some logging messages *
254
255PPP ON tama> close
256
257* The connection is closed and modem will be disconnected. *
258
259ppp ON tama> quit
260
261%
262
263.Sh AUTOMATIC DIALING
264
265To use automatic dialing, you must prepare some Dial and Login chat scripts.
266See the example definitions in
267.Pa /etc/ppp/ppp.conf.sample
268(the format of ppp.conf is pretty simple).
269
270.Bl -bullet -compact
271.It
272Each line contains one command, label or comment.
273.It
274A line starting with a
275.Sq #
276character is treated as a comment line.
277.It
278A label name has to start in the first column and should be followed by
279a colon (:).
280.It
281A command line must contain a space or tab in the first column.
282.El
283
284Once ppp.conf is ready, specify the destination label name when you
285invoke
286.Nm ppp .
287Commands associated with the destination label are then
288executed. Note that the commands associated with the
289.Dq default
290label are ALWAYS executed.
291
292Once the connection is made, you'll find that the
293.Nm ppp
294portion of the prompt has changed to
295.Nm PPP .
296
297   % ppp pm2
298   ...
299   ppp ON tama> dial
300   dial OK!
301   login OK!
302   PPP ON tama>
303
304If the
305.Pa /etc/ppp/ppp.linkup
306file is available, its contents are executed
307when the
308.Em PPP
309connection is established.  See the provided example which adds a
310default route.  The string HISADDR represents the IP address of the
311remote peer.
312
313.Sh BACKGROUND DIALING
314
315If you want to establish a connection using
316.Nm ppp non-interactively (such as from a
317.Xr crontab(5)
318entry or an
319.Xr at(1)
320script) you should use the
321.Fl background
322option.  You must also specify the destination label in
323.Pa /etc/ppp/ppp.conf
324to use.
325
326When
327.Fl background
328is specified,
329.Nm
330attempts to establish the connection.  If this attempt fails,
331.Nm ppp
332exits immediately with a non-zero exit code.
333
334If it succeeds, then
335.Nm ppp
336becomes a daemon, and returns an exit status of zero to its caller.
337The daemon exits automatically if the connection is dropped by the
338remote system, or it receives a TERM signal.
339
340The file
341.Pa /var/run/ppp.tun0.pid
342contains the process id number of the
343.Nm ppp
344program that is using the tunnel device tun0.
345
346.Sh DIAL ON DEMAND
347
348To play with demand dialing, you must use the
349.Fl auto
350or
351.Fl ddial
352option.  You must also specify the destination label in
353.Pa /etc/ppp/ppp.conf
354to use.  It should contain the
355.Dq ifaddr
356command to define the remote peer's IP address. (refer to
357.Pa /etc/ppp/ppp.conf.sample )
358
359   % ppp -auto pm2demand
360   ...
361   %
362
363When
364.Fl auto
365or
366.Fl ddial
367is specified,
368.Nm
369runs as a daemon but you can still configure or examine its
370configuration by using the diagnostic port as follows:
371
372
373  % telnet localhost 3000
374    Trying 127.0.0.1...
375    Connected to localhost.spec.co.jp.
376    Escape character is '^]'.
377    User Process PPP. Written by Toshiharu OHNO.
378    Working as auto mode.
379    PPP on tama> show ipcp
380    what ?
381    PPP on tama> pass xxxx
382    PPP ON tama> show ipcp
383    IPCP [OPEND]
384      his side: xxxx
385      ....
386
387.Pp
388Each
389.Nm
390daemon has an associated port number which is computed as "3000 +
391tunnel_device_number". If 3000 is not good base number, edit defs.h in
392the ppp sources (
393.Pa /usr/src/usr.sbin/ppp )
394and recompile it.
395
396When an outgoing packet is detected,
397.Nm
398will perform the dialing action (chat script) and try to connect
399with the peer.
400
401If the connect fails, the default behavior is to wait 30 seconds
402and then attempt to connect when another outgoing packet is detected.
403This behavior can be changed with
404.Bd -literal -offset indent
405set redial seconds|random [dial_attempts]
406.Ed
407.Pp
408Seconds is the number of seconds to wait before attempting
409to connect again. If the argument is
410.Sq random ,
411the delay period is a random value between 0 and 30 seconds.
412.Sq dial_attempts
413is the number of times to try to connect for each outgoing packet
414that is received. The previous value is unchanged if this parameter
415is omitted.
416.Bd -literal -offset indent
417set redial 10 4
418.Ed
419.Pp
420will attempt to connect 4 times for each outgoing packet that is
421detected with a 10 second delay between each attempt.
422
423Modifying the dial delay is very useful when running
424.Nm
425in demand
426dial mode on both ends of the link. If each end has the same timeout,
427both ends wind up calling each other at the same time if the link
428drops and both ends have packets queued.
429
430 To terminate the program, type
431
432  PPP ON tama> close
433  ppp ON tama> quit all
434
435.Pp
436A simple
437.Dq quit
438command will terminate the telnet connection but not the program itself.
439You must use
440.Dq quit all
441to terminate the program as well.
442
443.Sh PACKET ALIASING
444
445The
446.Fl alias
447command line option enables packet aliasing.  This allows the
448ppp host to act as a masquerading gateway for other computers over
449a local area network.  Outgoing IP packets are are aliased so that
450they appear to come from the ppp host, and incoming packets are
451de-aliased so that they are routed to the correct machine on the
452local area network.
453
454Packet aliasing allows computers on private, unregistered
455subnets to have internet access, although they are invisible
456from the outside world.
457
458In general, correct ppp operation should first be verified
459with packet aliasing disabled.  Then, the
460.Fl alias
461option should be switched on, and network applications (web browser,
462telnet, ftp, ping, traceroute) should be checked on the ppp host.
463Finally, the same or similar applications should be checked on other
464computers in the LAN.
465
466If network applications work correctly on the ppp host, but not on
467other machines in the LAN, then the masquerading software is working
468properly, but the host is either not forwarding or possibly receiving
469IP packets.  Check that IP forwarding is enabled in /etc/sysconfig
470and that other machines have designated the ppp host as the gateway
471for the LAN.
472
473.Sh PACKET FILTERING
474
475This implementation supports packet filtering. There are three kinds of
476filters: ifilter, ofilter and dfilter.  Here are the basics:
477
478.Bl -bullet -compact
479.It
480A filter definition has the following syntax:
481
482set filter-name rule-no action [src_addr/src_width] [dst_addr/dst_width]
483[proto [src [lt|eq|gt] port ]] [dst [lt|eq|gt] port] [estab]
484.Bl -enum
485.It
486.Sq filter-name
487should be one of ifilter, ofilter, or dfilter.
488.It
489There are two actions:
490.Sq permit
491and
492.Sq deny .
493If a given packet
494matches the rule, the associated action is taken immediately.
495.It
496.Sq src_width
497and
498.Sq dst_width
499work like a netmask to represent an address range.
500.It
501.Sq proto
502must be one of icmp, udp or tcp.
503.It
504.Sq port number
505can be specified by number and service name from
506.Pa /etc/services .
507
508.El
509
510.It
511Each filter can hold up to 20 rules, starting from rule 0.
512
513The entire rule set is not effective until rule 0 is defined.
514
515.It
516If no rule is matched to a packet, that packet will be discarded
517(blocked).
518
519.It
520Use
521.Dq set filter-name -1
522to flush all rules.
523
524.El
525
526See
527.Pa /etc/ppp/ppp.conf.filter.example .
528
529
530.Sh RECEIVING INCOMING PPP CONNECTIONS (Method 1)
531
532To handle an incoming
533.Em PPP
534connection request, follow these steps:
535
536.Bl -enum
537.It
538Make sure the modem and (optionally)
539.Pa /etc/rc.serial
540is configured correctly.
541.Bl -bullet -compact
542.It
543Use Hardware Handshake (CTS/RTS) for flow control.
544.It
545Modem should be set to NO echo back (ATE0) and NO results string (ATQ1).
546.El
547
548.It
549Edit
550.Pa /etc/ttys
551to enable a getty on the port where the modem is attached.
552
553For example:
554
555.Dl ttyd1  "/usr/libexec/getty std.38400" dialup on secure
556
557Don't forget to send a HUP signal to the init process to start the getty.
558
559.Dl # kill -HUP 1
560
561.It
562Prepare an account for the incoming user.
563.Bd -literal
564ppp:xxxx:66:66:PPP Login User:/home/ppp:/usr/local/bin/ppplogin
565.Ed
566
567.It
568Create a
569.Pa /usr/local/bin/ppplogin
570file with the following contents:
571.Bd -literal -offset indent
572#!/bin/sh -p
573exec /usr/sbin/ppp -direct
574.Ed
575
576(You can specify a label name for further control.)
577
578.Pp
579Direct mode (
580.Fl direct )
581lets
582.Nm
583work with stdin and stdout.  You can also telnet to port 3000 to get
584command mode control in the same manner as client-side
585.Nm.
586
587.It
588Optional support for Microsoft's IPCP Name Server and NetBIOS
589Name Server negotiation can be enabled use
590.Dq enable msext
591and
592.Dq set ns pri-addr [sec-addr]
593along with
594.Dq set nbns pri-addr [sec-addr]
595in your ppp.conf file
596
597.El
598
599.Sh RECEIVING INCOMING PPP CONNECTIONS (Method 2)
600
601This method differs in that it recommends the use of
602.Em mgetty+sendfax
603to handle the modem connections.  The latest version 0.99
604can be compiled with the
605.Dq AUTO_PPP
606option to allow detection of clients speaking PPP to the login
607prompt.
608
609Follow these steps:
610
611.Bl -enum
612.It
613Get, configure, and install mgetty+sendfax v0.99 or later (beta)
614making sure you have used the AUTO_PPP option.
615.It
616Edit
617.Pa /etc/ttys
618to enable a mgetty on the port where the modem is attached.
619
620For example:
621
622.Dl cuaa1  "/usr/local/sbin/mgetty -s 57600"       dialup on
623
624.It
625Prepare an account for the incoming user.
626.Bd -literal
627Pfred:xxxx:66:66:Fred's PPP:/home/ppp:/etc/ppp/ppp-dialup
628.Ed
629
630.It
631Examine the files
632.Pa /etc/ppp/sample.ppp-dialup
633.Pa /etc/ppp/sample.ppp-pap-dialup
634and
635.Pa /etc/ppp/sample.ppp.conf
636for ideas.   ppp-pap-dialup is supposed to be called from
637.Pa /usr/local/etc/mgetty+sendfax/login.conf
638from a line like
639
640.Dl /AutoPPP/ -     -       /etc/ppp/ppp-pap-dialup
641
642.Sh SETTING IDLE, LINE QUALITY REQUEST, RETRY TIMER
643
644To check/set idletimer, use the
645.Dq show timeout
646and
647.Dq set timeout [lqrtimer [retrytimer]]
648commands.
649
650 Ex:
651.Dl ppp ON tama> set timeout 600
652
653The timeout period is measured in seconds, the  default values for which
654are timeout = 180 or 3 min, lqrtimer = 30sec and retrytimer = 3sec.
655To disable the idle timer function,
656use the command
657.Dq set timeout 0 .
658
659In
660.Fl auto
661mode, an idle timeout causes the
662.Em PPP
663session to be
664closed, though the
665.Nm
666program itself remains running.  Another trigger packet will cause it to
667attempt to reestablish the link.
668
669.Sh Predictor-1 compression
670
671This version supports CCP and Predictor type 1 compression based on
672the current IETF-draft specs. As a default behavior,
673.Nm
674will attempt to use (or be willing to accept) this capability when the
675peer agrees (or requests it).
676
677To disable CCP/predictor functionality completely, use the
678.Dq disable pred1
679and
680.Dq deny pred1
681commands.
682
683.Sh Controlling IP address
684
685.Nm
686uses IPCP to negotiate IP addresses. Each side of the connection
687specifies the IP address that it's willing to use, and if the requested
688IP address is acceptable then
689.Nm
690returns ACK to the requester.  Otherwise,
691.Nm
692returns NAK to suggest that the peer use a different IP address. When
693both sides of the connection agree to accept the received request (and
694send ACK), IPCP is set to the open state and a network level connection
695is established.
696
697To control this IPCP behavior, this implementation has the
698.Dq set ifaddr
699command for defining the local and remote IP address:
700
701.Nm set ifaddr
702.Op src_addr Op dst_addr Op netmask Op trg_addr
703
704Where,
705.Sq src_addr
706is the IP address that the local side is willing to use and
707.Sq dst_addr
708is the IP address which the remote side should use.
709.Sq netmask
710is interface netmask.
711.Sq trg_addr
712is the IP address which used in address negotiation.
713
714Ex:
715.Dl set ifaddr 192.244.177.38 192.244.177.2 255.255.255.0
716
717The above specification means:
718.Bl -bullet -compact
719.It
720I strongly want to use 192.244.177.38 as my IP address, and I'll
721disagree if the peer suggests that I use another address.
722
723.It
724I strongly insist that peer use 192.244.177.2 as own side address and
725don't permit it to use any IP address but 192.244.177.2.  When peer
726request another IP address, I always suggest that it use 192.244.177.2.
727
728.It
729My interface netmask will be 255.255.255.0.
730
731.It
732This is all fine when each side has a pre-determined IP address, however
733it is often the case that one side is acting as a server which controls
734all IP addresses and the other side should obey the direction from it.
735.El
736
737In order to allow more flexible behavior, `ifaddr' variable allows the
738user to specify IP address more loosely:
739
740.Dl set ifaddr 192.244.177.38/24 192.244.177.2/20
741
742A number followed by a slash (/) represent the number of bits significant in
743the IP address.  The above example signifies that:
744
745.Bl -bullet -compact
746.It
747I'd like to use 192.244.177.38 as my address if it is possible, but I'll
748also accept any IP address between 192.244.177.0 and 192.244.177.255.
749
750.It
751I'd like to make him use 192.244.177.2 as his own address, but I'll also
752permit him to use any IP address between 192.244.176.0 and
753192.244.191.255.
754
755.It
756As you may have already noticed, 192.244.177.2 is equivalent to saying
757192.244.177.2/32.
758
759.It
760As an exception, 0 is equivalent to 0.0.0.0/0, meaning that I have no
761preferred IP address and will obey the remote peer's selection.
762
763.It
764192.244.177.2/0 means that I'll accept/permit any IP address but I'll
765try to insist that 192.244.177.2 be used first.
766.El
767
768.Sh Connecting with your service provider
769
770.Bl -enum
771.It
772Describe provider's phone number(s) in DialScript: Use the
773.Dq set dial
774or
775.Dq set phone
776commands.
777.Dq Set phone
778command allows you to set multiply phone numbers for dialing and redialing
779separated by a colon (:).
780.It
781Describe login procedure in LoginScript: Use the
782.Dq set login
783command.
784.It
785Use
786.Dq set ifaddr
787command to define the IP address.
788.Bl -bullet
789.It
790If you know what IP address provider uses, then use it as the remote address.
791.It
792If provider has assigned a particular IP address to you, then use it as
793your address.
794.It
795If provider assigns your address dynamically, use 0 as your address.
796.It
797If you have no idea which IP addresses to use, then try
798.Dq set ifaddr 0 0 .
799.El
800.It
801If provider requests that you use PAP/CHAP authentication methods, add
802the next lines to your
803.Pa ppp.conf
804file:
805.Bd -literal -offset indent
806enable pap (or enable chap)
807disable chap (or disable pap)
808set authname MyName
809set authkey MyPassword
810.Ed
811.El
812
813Please refer to
814.Pa /etc/ppp/ppp.conf.iij
815for some real examples.
816
817.Sh Logging facility
818
819.Nm
820is able to generate the following log info into
821.Pa /var/log/ppp.log :
822
823.Bl -column SMMMMMM -offset indent -compat
824.It Li Phase	Phase transition log output
825.It Li Chat	Generate Chat script trace log
826.It Li Connect	Generate complete Chat log
827.It Li Carrier	Log Chat lines with 'CARRIER'
828.It Li LQM	Generate LQR report
829.It Li LCP	Generate LCP/IPCP packet trace
830.It Li Link	Log address assignments and link up/down events
831.It Li TCP/IP	Dump TCP/IP packet
832.It Li HDLC	Dump HDLC packet in hex
833.It Li Async	Dump async level packet in hex
834.El
835
836The
837.Dq set debug
838command allows you to set logging output level, of which
839multiple levels can be specified.  The default is equivalent to
840.Dq set debug carrier link phase .
841
842If a HUP signal is received, the log file is closed and re-opened
843to facilitate log file rotation.
844
845.Sh MORE DETAILS
846
847.Bl -bullet -compact
848.It
849Please read the Japanese doc for complete explanation. It may not be
850useful for non-japanese readers,  but examples in the document may help
851you to guess.
852
853.It
854Please read example configuration files.
855
856.It
857Use
858.Dq help ,
859.Dq show ? ,
860.Dq set ?
861and
862.Dq set ? <var>
863commands.
864
865.It
866NetBSD and BSDI-1.0 were supported in previous releases but are no
867longer supported in this release.  Please contact the author if you need
868old driver code.
869.El
870
871.Sh FILES
872.Nm
873refers to three files: ppp.conf, ppp.linkup and ppp.secret.
874These files are placed in
875.Pa /etc/ppp ,
876but the user can create his own files under his $HOME directory as
877.Pa .ppp.conf ,
878.Pa .ppp.linkup
879and
880.Pa .ppp.secret.
881.Nm
882will always try to consult the user's personal setup first.
883
884.Bl -tag -width flag
885.Pa $HOME/ppp/.ppp.[conf|linkup|secret]
886User dependent configuration files.
887
888.Pa /etc/ppp/ppp.conf
889System default configuration file.
890
891.Pa /etc/ppp/ppp.secret
892An authorization file for each system.
893
894.Pa /etc/ppp/ppp.linkup
895A file to check when
896.Nm
897establishes a network level connection.
898
899.Pa /var/log/ppp.log
900Logging and debugging information file.
901
902.Pa /var/spool/lock/Lck..*
903tty port locking file.
904
905.Pa /var/run/PPP.system
906Holds the pid for ppp -auto system.
907
908.Pa /var/run/ppp.tun0.pid
909The process id (pid) of the ppp program connected to the ppp0 device.
910
911.Pa /etc/services
912Get port number if port number is using service name.
913.El
914.Sh SEE ALSO
915.Xr chat 8 ,
916.Xr pppd 8
917.Sh HISTORY
918This program was submitted in FreeBSD-2.0.5 Atsushi Murai (amurai@spec.co.jp).
919
920.Sh AUTHORS
921Toshiharu OHNO (tony-o@iij.ad.jp)
922