4 .\" Copyright (c) 2001 Brian Somers <brian@Awfulhak.org>
5 .\" All rights reserved.
7 .\" Redistribution and use in source and binary forms, with or without
8 .\" modification, are permitted provided that the following conditions
10 .\" 1. Redistributions of source code must retain the above copyright
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12 .\" 2. Redistributions in binary form must reproduce the above copyright
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16 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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19 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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23 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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28 .\" $FreeBSD: src/usr.sbin/ppp/ppp.8.m4,v 1.301.2.1 2002/09/01 02:12:31 brian Exp $
29 .\" $DragonFly: src/usr.sbin/ppp/ppp.8.m4,v 1.5 2006/03/26 22:56:58 swildner Exp $
31 .Dd September 20, 1995
36 .Nd Point to Point Protocol (a.k.a. user-ppp)
45 This is a user process
50 is implemented as a part of the kernel (e.g., as managed by
52 and it's thus somewhat hard to debug and/or modify its behaviour.
53 However, in this implementation
55 is done as a user process with the help of the
56 tunnel device driver (tun).
60 flag does the equivalent of a
64 network address translation features.
67 to act as a NAT or masquerading engine for all machines on an internal
69 ifdef({LOCALNAT},{},{Refer to
71 for details on the technical side of the NAT engine.
74 .Sx NETWORK ADDRESS TRANSLATION (PACKET ALIASING)
75 section of this manual page for details on how to configure NAT in
82 to be silent at startup rather than displaying the mode and interface
89 to only attempt to open
90 .Pa /dev/tun Ns Ar N .
93 will start with a value of 0 for
95 and keep trying to open a tunnel device by incrementing the value of
97 by one each time until it succeeds.
98 If it fails three times in a row
99 because the device file is missing, it gives up.
105 .Bl -tag -width XXX -offset XXX
108 opens the tun interface, configures it then goes into the background.
109 The link isn't brought up until outgoing data is detected on the tun
110 interface at which point
112 attempts to bring up the link.
113 Packets received (including the first one) while
115 is trying to bring the link up will remain queued for a default of
125 must be given on the command line (see below) and a
127 must be done in the system profile that specifies a peer IP address to
128 use when configuring the interface.
131 is usually appropriate.
135 .Pa /usr/share/examples/ppp/ppp.conf.sample
140 attempts to establish a connection with the peer immediately.
143 goes into the background and the parent process returns an exit code
147 exits with a non-zero result.
151 attempts to establish a connection with the peer immediately, but never
153 The link is created in background mode.
154 This is useful if you wish to control
156 invocation from another process.
158 This is used for receiving incoming connections.
162 line and uses descriptor 0 as the link.
164 If callback is configured,
168 information when dialing back.
170 This option is designed for machines connected with a dedicated
173 will always keep the device open and will never use any configured
176 This mode is equivalent to
180 will bring the link back up any time it's dropped for any reason.
182 This is a no-op, and gives the same behaviour as if none of the above
183 modes have been specified.
185 loads any sections specified on the command line then provides an
189 One or more configuration entries or systems
191 .Pa /etc/ppp/ppp.conf )
192 may also be specified on the command line.
197 .Pa /etc/ppp/ppp.conf
198 at startup, followed by each of the systems specified on the command line.
201 .It Provides an interactive user interface.
202 Using its command mode, the user can
203 easily enter commands to establish the connection with the remote end, check
204 the status of connection and close the connection.
205 All functions can also be optionally password protected for security.
206 .It Supports both manual and automatic dialing.
207 Interactive mode has a
209 command which enables you to talk to the device directly.
210 When you are connected to the remote peer and it starts to talk
213 detects it and switches to packet mode automatically.
215 determined the proper sequence for connecting with the remote host, you
216 can write a chat script to {define} the necessary dialing and login
217 procedure for later convenience.
218 .It Supports on-demand dialup capability.
223 will act as a daemon and wait for a packet to be sent over the
226 When this happens, the daemon automatically dials and establishes the
228 In almost the same manner
230 mode (direct-dial mode) also automatically dials and establishes the
232 However, it differs in that it will dial the remote site
233 any time it detects the link is down, even if there are no packets to be
235 This mode is useful for full-time connections where we worry less
236 about line charges and more about being connected full time.
239 mode is also available.
240 This mode is targeted at a dedicated link between two machines.
242 will never voluntarily quit from dedicated mode - you must send it the
244 command via its diagnostic socket.
247 will force an LCP renegotiation, and a
249 will force it to exit.
250 .It Supports client callback.
252 can use either the standard LCP callback protocol or the Microsoft
253 CallBack Control Protocol (ftp://ftp.microsoft.com/developr/rfc/cbcp.txt).
254 .It Supports NAT or packet aliasing.
255 Packet aliasing (a.k.a. IP masquerading) allows computers on a
256 private, unregistered network to access the Internet.
259 host acts as a masquerading gateway.
260 IP addresses as well as TCP and
261 UDP port numbers are NAT'd for outgoing packets and de-NAT'd for
263 .It Supports background PPP connections.
264 In background mode, if
266 successfully establishes the connection, it will become a daemon.
267 Otherwise, it will exit with an error.
268 This allows the setup of
269 scripts that wish to execute certain commands only if the connection
270 is successfully established.
271 .It Supports server-side PPP connections.
274 acts as server which accepts incoming
276 connections on stdin/stdout.
277 .It "Supports PAP and CHAP (rfc 1994, 2433 and 2759) authentication.
278 With PAP or CHAP, it is possible to skip the Unix style
280 procedure, and use the
282 protocol for authentication instead.
283 If the peer requests Microsoft CHAP authentication and
285 is compiled with DES support, an appropriate MD4/DES response will be
287 .It Supports RADIUS (rfc 2138 & 2548) authentication.
288 An extension to PAP and CHAP,
295 allows authentication information to be stored in a central or
296 distributed database along with various per-user framed connection
298 ifdef({LOCALRAD},{},{If
300 is available at compile time,
304 requests when configured to do so.
306 .It Supports Proxy Arp.
308 can be configured to make one or more proxy arp entries on behalf of
310 This allows routing from the peer to the LAN without
311 configuring each machine on that LAN.
312 .It Supports packet filtering.
313 User can {define} four kinds of filters: the
315 filter for incoming packets, the
317 filter for outgoing packets, the
319 filter to {define} a dialing trigger packet and the
321 filter for keeping a connection alive with the trigger packet.
322 .It Tunnel driver supports bpf.
325 to check the packet flow over the
328 .It Supports PPP over TCP and PPP over UDP.
329 If a device name is specified as
330 .Em host Ns No : Ns Em port Ns
335 will open a TCP or UDP connection for transporting data rather than using a
336 conventional serial device.
337 UDP connections force
339 into synchronous mode.
340 .It Supports PPP over ISDN.
343 is given a raw B-channel i4b device to open as a link, it's able to talk
346 daemon to establish an ISDN connection.
347 .It Supports PPP over Ethernet (rfc 2516).
350 is given a device specification of the format
351 .No PPPoE: Ns Ar iface Ns Xo
352 .Op \&: Ns Ar provider Ns
366 On systems that do not support
368 an external program such as
371 .It "Supports IETF draft Predictor-1 (rfc 1978) and DEFLATE (rfc 1979) compression."
373 supports not only VJ-compression but also Predictor-1 and DEFLATE compression.
374 Normally, a modem has built-in compression (e.g., v42.bis) and the system
375 may receive higher data rates from it as a result of such compression.
376 While this is generally a good thing in most other situations, this
377 higher speed data imposes a penalty on the system by increasing the
378 number of serial interrupts the system has to process in talking to the
379 modem and also increases latency.
380 Unlike VJ-compression, Predictor-1 and DEFLATE compression pre-compresses
382 network traffic flowing through the link, thus reducing overheads to a
384 .It Supports Microsoft's IPCP extensions (rfc 1877).
385 Name Server Addresses and NetBIOS Name Server Addresses can be negotiated
386 with clients using the Microsoft
388 stack (i.e., Win95, WinNT)
389 .It Supports Multi-link PPP (rfc 1990)
390 It is possible to configure
392 to open more than one physical connection to the peer, combining the
393 bandwidth of all links for better throughput.
394 .It Supports MPPE (draft-ietf-pppext-mppe)
395 MPPE is Microsoft Point to Point Encryption scheme.
396 It is possible to configure
398 to participate in Microsoft's Windows VPN.
401 can only get encryption keys from CHAP 81 authentication.
403 must be compiled with DES for MPPE to operate.
404 .It Supports IPV6CP (rfc 2023).
405 An IPv6 connection can be made in addition to or instead of the normal
418 will not run if the invoking user id is not zero.
419 This may be overridden by using the
422 .Pa /etc/ppp/ppp.conf .
423 When running as a normal user,
425 switches to user id 0 in order to alter the system routing table, set up
426 system lock files and read the ppp configuration files.
427 All external commands (executed via the "shell" or "!bg" commands) are executed
428 as the user id that invoked
432 logging facility if you're interested in what exactly is done as user id
437 you may need to deal with some initial configuration details.
440 Your kernel must {include} a tunnel device (the GENERIC kernel includes
442 If it doesn't, or if you require more than one tun
443 interface, you'll need to rebuild your kernel with the following line in
444 your kernel configuration file:
446 .Dl pseudo-device tun N
450 is the maximum number of
452 connections you wish to support.
456 directory for the tunnel device entries
460 represents the number of the tun device, starting at zero.
461 If they don't exist, you can create them by running "sh ./MAKEDEV tunN".
462 This will create tun devices 0 through
465 Make sure that your system has a group named
469 file and that the group contains the names of all users expected to use
473 manual page for details.
474 Each of these users must also be given access using the
477 .Pa /etc/ppp/ppp.conf .
484 A common log file name is
485 .Pa /var/log/ppp.log .
486 To make output go to this file, put the following lines in the
489 .Bd -literal -offset indent
491 *.*<TAB>/var/log/ppp.log
494 It is possible to have more than one
496 log file by creating a link to the
504 .Bd -literal -offset indent
506 *.*<TAB>/var/log/ppp0.log
510 .Pa /etc/syslog.conf .
511 Don't forget to send a
516 .Pa /etc/syslog.conf .
518 Although not strictly relevant to
520 operation, you should configure your resolver so that it works correctly.
521 This can be done by configuring a local DNS
524 or by adding the correct
527 .Pa /etc/resolv.conf .
530 manual page for details.
532 Alternatively, if the peer supports it,
534 can be configured to ask the peer for the nameserver address(es) and to
542 commands below for details.
545 In the following examples, we assume that your machine name is
551 above) with no arguments, you are presented with a prompt:
552 .Bd -literal -offset indent
558 part of your prompt should always be in upper case.
559 If it is in lower case, it means that you must supply a password using the
562 This only ever happens if you connect to a running version of
564 and have not authenticated yourself using the correct password.
566 You can start by specifying the device name and speed:
567 .Bd -literal -offset indent
568 ppp ON awfulhak> set device /dev/cuaa0
569 ppp ON awfulhak> set speed 38400
572 Normally, hardware flow control (CTS/RTS) is used.
574 certain circumstances (as may happen when you are connected directly
575 to certain PPP-capable terminal servers), this may result in
577 hanging as soon as it tries to write data to your communications link
578 as it is waiting for the CTS (clear to send) signal - which will never
580 Thus, if you have a direct line and can't seem to make a
581 connection, try turning CTS/RTS off with
583 If you need to do this, check the
585 description below too - you'll probably need to
586 .Dq set accmap 000a0000 .
588 Usually, parity is set to
593 Parity is a rather archaic error checking mechanism that is no
594 longer used because modern modems do their own error checking, and most
595 link-layer protocols (that's what
597 is) use much more reliable checking mechanisms.
598 Parity has a relatively
599 huge overhead (a 12.5% increase in traffic) and as a result, it is always
606 However, some ISPs (Internet Service Providers) may use
607 specific parity settings at connection time (before
610 Notably, Compuserve insist on even parity when logging in:
611 .Bd -literal -offset indent
612 ppp ON awfulhak> set parity even
615 You can now see what your current device settings look like:
616 .Bd -literal -offset indent
617 ppp ON awfulhak> show physical
621 Link Type: interactive
627 Device List: /dev/cuaa0
628 Characteristics: 38400bps, cs8, even parity, CTS/RTS on
631 0 octets in, 0 octets out
636 The term command can now be used to talk directly to the device:
637 .Bd -literal -offset indent
638 ppp ON awfulhak> term
644 Password: myisppassword
648 When the peer starts to talk in
651 detects this automatically and returns to command mode.
652 .Bd -literal -offset indent
653 ppp ON awfulhak> # No link has been established
654 Ppp ON awfulhak> # We've connected & finished LCP
655 PPp ON awfulhak> # We've authenticated
656 PPP ON awfulhak> # We've agreed IP numbers
659 If it does not, it's probable that the peer is waiting for your end to
665 configuration packets to the peer, use the
667 command to drop out of terminal mode and enter packet mode.
669 If you never even receive a login prompt, it is quite likely that the
670 peer wants to use PAP or CHAP authentication instead of using Unix-style
671 login/password authentication.
672 To set things up properly, drop back to
673 the prompt and set your authentication name and key, then reconnect:
674 .Bd -literal -offset indent
676 ppp ON awfulhak> set authname myispusername
677 ppp ON awfulhak> set authkey myisppassword
678 ppp ON awfulhak> term
685 You may need to tell ppp to initiate negotiations with the peer here too:
686 .Bd -literal -offset indent
688 ppp ON awfulhak> # No link has been established
689 Ppp ON awfulhak> # We've connected & finished LCP
690 PPp ON awfulhak> # We've authenticated
691 PPP ON awfulhak> # We've agreed IP numbers
694 You are now connected!
697 in the prompt has changed to capital letters to indicate that you have
699 If only some of the three Ps go uppercase, wait until
700 either everything is uppercase or lowercase.
701 If they revert to lowercase, it means that
703 couldn't successfully negotiate with the peer.
704 A good first step for troubleshooting at this point would be to
705 .Bd -literal -offset indent
706 ppp ON awfulhak> set log local phase lcp ipcp
712 command description below for further details.
713 If things fail at this point,
714 it is quite important that you turn logging on and try again.
716 important that you note any prompt changes and report them to anyone trying
719 When the link is established, the show command can be used to see how
721 .Bd -literal -offset indent
722 PPP ON awfulhak> show physical
723 * Modem related information is shown here *
724 PPP ON awfulhak> show ccp
725 * CCP (compression) related information is shown here *
726 PPP ON awfulhak> show lcp
727 * LCP (line control) related information is shown here *
728 PPP ON awfulhak> show ipcp
729 * IPCP (IP) related information is shown here *
730 PPP ON awfulhak> show ipv6cp
731 * IPV6CP (IPv6) related information is shown here *
732 PPP ON awfulhak> show link
733 * Link (high level) related information is shown here *
734 PPP ON awfulhak> show bundle
735 * Logical (high level) connection related information is shown here *
738 At this point, your machine has a host route to the peer.
740 that you can only make a connection with the host on the other side
742 If you want to add a default route entry (telling your
743 machine to send all packets without another routing entry to the other
746 link), enter the following command:
747 .Bd -literal -offset indent
748 PPP ON awfulhak> add default HISADDR
753 represents the IP address of the connected peer.
756 command fails due to an existing route, you can overwrite the existing
758 .Bd -literal -offset indent
759 PPP ON awfulhak> add! default HISADDR
762 This command can also be executed before actually making the connection.
763 If a new IP address is negotiated at connection time,
765 will update your default route accordingly.
767 You can now use your network applications (ping, telnet, ftp etc.)
768 in other windows or terminals on your machine.
769 If you wish to reuse the current terminal, you can put
771 into the background using your standard shell suspend and background
779 section for details on all available commands.
780 .Sh AUTOMATIC DIALING
781 To use automatic dialing, you must prepare some Dial and Login chat scripts.
782 See the example definitions in
783 .Pa /usr/share/examples/ppp/ppp.conf.sample
785 .Pa /etc/ppp/ppp.conf
787 Each line contains one comment, inclusion, label or command:
790 A line starting with a
792 character is treated as a comment line.
793 Leading whitespace are ignored when identifying comment lines.
795 An inclusion is a line beginning with the word
797 It must have one argument - the file to {include}.
799 .Dq {!include} ~/.ppp.conf
800 for compatibility with older versions of
803 A label name starts in the first column and is followed by
807 A command line must contain a space or tab in the first column.
811 .Pa /etc/ppp/ppp.conf
812 file should consist of at least a
815 This section is always executed.
816 It should also contain
817 one or more sections, named according to their purpose, for example,
819 would represent your ISP, and
821 would represent an incoming
824 You can now specify the destination label name when you invoke
826 Commands associated with the
828 label are executed, followed by those associated with the destination
832 is started with no arguments, the
834 section is still executed.
835 The load command can be used to manually load a section from the
836 .Pa /etc/ppp/ppp.conf
838 .Bd -literal -offset indent
839 ppp ON awfulhak> load MyISP
842 Note, no action is taken by
844 after a section is loaded, whether it's the result of passing a label on
845 the command line or using the
848 Only the commands specified for that label in the configuration
850 However, when invoking
857 switches, the link mode tells
859 to establish a connection.
862 command below for further details.
864 Once the connection is made, the
866 portion of the prompt will change to
868 .Bd -literal -offset indent
871 ppp ON awfulhak> dial
877 The Ppp prompt indicates that
879 has entered the authentication phase.
880 The PPp prompt indicates that
882 has entered the network phase.
883 The PPP prompt indicates that
885 has successfully negotiated a network layer protocol and is in
889 .Pa /etc/ppp/ppp.linkup
890 file is available, its contents are executed
893 connection is established.
897 .Pa /usr/share/examples/ppp/ppp.conf.sample
898 which runs a script in the background after the connection is established
903 commands below for a description of possible substitution strings).
904 Similarly, when a connection is closed, the contents of the
905 .Pa /etc/ppp/ppp.linkdown
907 Both of these files have the same format as
908 .Pa /etc/ppp/ppp.conf .
910 In previous versions of
912 it was necessary to re-add routes such as the default route in the
918 where all routes that contain the
924 literals will automatically be updated when the values of these variables
926 .Sh BACKGROUND DIALING
927 If you want to establish a connection using
929 non-interactively (such as from a
933 job) you should use the
940 attempts to establish the connection immediately.
942 numbers are specified, each phone number will be tried once.
943 If the attempt fails,
945 exits immediately with a non-zero exit code.
948 becomes a daemon, and returns an exit status of zero to its caller.
949 The daemon exits automatically if the connection is dropped by the
950 remote system, or it receives a
954 Demand dialing is enabled with the
959 You must also specify the destination label in
960 .Pa /etc/ppp/ppp.conf
964 command to {define} the remote peers IP address.
966 .Pa /usr/share/examples/ppp/ppp.conf.sample )
967 .Bd -literal -offset indent
977 runs as a daemon but you can still configure or examine its
978 configuration by using the
981 .Pa /etc/ppp/ppp.conf ,
983 .Dq Li "set server +3000 mypasswd" )
984 and connecting to the diagnostic port as follows:
985 .Bd -literal -offset indent
986 # pppctl 3000 (assuming tun0)
988 PPP ON awfulhak> show who
989 tcp (127.0.0.1:1028) *
994 command lists users that are currently connected to
997 If the diagnostic socket is closed or changed to a different
998 socket, all connections are immediately dropped.
1002 mode, when an outgoing packet is detected,
1004 will perform the dialing action (chat script) and try to connect
1008 mode, the dialing action is performed any time the line is found
1010 If the connect fails, the default behaviour is to wait 30 seconds
1011 and then attempt to connect when another outgoing packet is detected.
1012 This behaviour can be changed using the
1016 .No set redial Ar secs Ns Xo
1019 .Oc Ns Op . Ns Ar next
1023 .Bl -tag -width attempts -compact
1025 is the number of seconds to wait before attempting
1027 If the argument is the literal string
1029 the delay period is a random value between 1 and 30 seconds inclusive.
1031 is the number of seconds that
1033 should be incremented each time a new dial attempt is made.
1034 The timeout reverts to
1036 only after a successful connection is established.
1037 The default value for
1041 is the maximum number of times
1045 The default value for
1049 is the number of seconds to wait before attempting
1050 to dial the next number in a list of numbers (see the
1053 The default is 3 seconds.
1054 Again, if the argument is the literal string
1056 the delay period is a random value between 1 and 30 seconds.
1058 is the maximum number of times to try to connect for each outgoing packet
1059 that triggers a dial.
1060 The previous value is unchanged if this parameter is omitted.
1061 If a value of zero is specified for
1064 will keep trying until a connection is made.
1068 .Bd -literal -offset indent
1072 will attempt to connect 4 times for each outgoing packet that causes
1073 a dial attempt with a 3 second delay between each number and a 10 second
1074 delay after all numbers have been tried.
1075 If multiple phone numbers
1076 are specified, the total number of attempts is still 4 (it does not
1077 attempt each number 4 times).
1081 .Bd -literal -offset indent
1082 set redial 10+10-5.3 20
1087 to attempt to connect 20 times.
1088 After the first attempt,
1090 pauses for 10 seconds.
1091 After the next attempt it pauses for 20 seconds
1092 and so on until after the sixth attempt it pauses for 1 minute.
1093 The next 14 pauses will also have a duration of one minute.
1096 connects, disconnects and fails to connect again, the timeout starts again
1099 Modifying the dial delay is very useful when running
1103 mode on both ends of the link.
1104 If each end has the same timeout,
1105 both ends wind up calling each other at the same time if the link
1106 drops and both ends have packets queued.
1107 At some locations, the serial link may not be reliable, and carrier
1108 may be lost at inappropriate times.
1109 It is possible to have
1111 redial should carrier be unexpectedly lost during a session.
1112 .Bd -literal -offset indent
1113 set reconnect timeout ntries
1118 to re-establish the connection
1120 times on loss of carrier with a pause of
1122 seconds before each try.
1124 .Bd -literal -offset indent
1130 that on an unexpected loss of carrier, it should wait
1132 seconds before attempting to reconnect.
1133 This may happen up to
1138 The default value of ntries is zero (no reconnect).
1139 Care should be taken with this option.
1140 If the local timeout is slightly
1141 longer than the remote timeout, the reconnect feature will always be
1142 triggered (up to the given number of times) after the remote side
1143 times out and hangs up.
1144 NOTE: In this context, losing too many LQRs constitutes a loss of
1145 carrier and will trigger a reconnect.
1148 flag is specified, all phone numbers are dialed at most once until
1149 a connection is made.
1150 The next number redial period specified with the
1152 command is honoured, as is the reconnect tries value.
1154 value is less than the number of phone numbers specified, not all
1155 the specified numbers will be tried.
1156 To terminate the program, type
1157 .Bd -literal -offset indent
1158 PPP ON awfulhak> close
1159 ppp ON awfulhak> quit all
1164 command will terminate the
1168 connection but not the
1176 .Sh RECEIVING INCOMING PPP CONNECTIONS (Method 1)
1177 To handle an incoming
1179 connection request, follow these steps:
1182 Make sure the modem and (optionally)
1184 is configured correctly.
1185 .Bl -bullet -compact
1187 Use Hardware Handshake (CTS/RTS) for flow control.
1189 Modem should be set to NO echo back (ATE0) and NO results string (ATQ1).
1197 on the port where the modem is attached.
1200 .Dl ttyd1 Qo /usr/libexec/getty std.38400 Qc dialup on secure
1202 Don't forget to send a
1206 process to start the
1211 It is usually also necessary to train your modem to the same DTR speed
1213 .Bd -literal -offset indent
1215 ppp ON awfulhak> set device /dev/cuaa1
1216 ppp ON awfulhak> set speed 38400
1217 ppp ON awfulhak> term
1218 deflink: Entering terminal mode on /dev/cuaa1
1229 ppp ON awfulhak> quit
1233 .Pa /usr/local/bin/ppplogin
1234 file with the following contents:
1235 .Bd -literal -offset indent
1237 exec /usr/sbin/ppp -direct incoming
1244 work with stdin and stdout.
1247 to connect to a configured diagnostic port, in the same manner as with
1253 section must be set up in
1254 .Pa /etc/ppp/ppp.conf .
1258 section contains the
1260 command as appropriate.
1262 Prepare an account for the incoming user.
1264 ppp:xxxx:66:66:PPP Login User:/home/ppp:/usr/local/bin/ppplogin
1267 Refer to the manual entries for
1273 Support for IPCP Domain Name Server and NetBIOS Name Server negotiation
1274 can be enabled using the
1279 Refer to their descriptions below.
1281 .Sh RECEIVING INCOMING PPP CONNECTIONS (Method 2)
1282 This method differs in that we use
1284 to authenticate the connection rather than
1288 Configure your default section in
1290 with automatic ppp recognition by specifying the
1295 :pp=/usr/local/bin/ppplogin:\\
1299 Configure your serial device(s), enable a
1302 .Pa /usr/local/bin/ppplogin
1303 as in the first three steps for method 1 above.
1311 .Pa /etc/ppp/ppp.conf
1314 label (or whatever label
1319 .Pa /etc/ppp/ppp.secret
1320 for each incoming user:
1329 detects a ppp connection (by recognising the HDLC frame headers), it runs
1330 .Dq /usr/local/bin/ppplogin .
1334 that either PAP or CHAP are enabled as above.
1335 If they are not, you are
1336 allowing anybody to establish a ppp session with your machine
1338 a password, opening yourself up to all sorts of potential attacks.
1339 .Sh AUTHENTICATING INCOMING CONNECTIONS
1340 Normally, the receiver of a connection requires that the peer
1341 authenticates itself.
1342 This may be done using
1344 but alternatively, you can use PAP or CHAP.
1345 CHAP is the more secure of the two, but some clients may not support it.
1346 Once you decide which you wish to use, add the command
1350 to the relevant section of
1353 You must then configure the
1354 .Pa /etc/ppp/ppp.secret
1356 This file contains one line per possible client, each line
1357 containing up to five fields:
1360 .Ar hisaddr Op Ar label Op Ar callback-number
1367 specify the client username and password.
1372 and PAP is being used,
1374 will look up the password database
1376 when authenticating.
1377 If the client does not offer a suitable response based on any
1378 .Ar name Ns No / Ns Ar key
1381 authentication fails.
1383 If authentication is successful,
1386 is used when negotiating IP numbers.
1389 command for details.
1391 If authentication is successful and
1393 is specified, the current system label is changed to match the given
1395 This will change the subsequent parsing of the
1401 If authentication is successful and
1407 the client will be called back on the given number.
1408 If CBCP is being used,
1410 may also contain a list of numbers or a
1415 The value will be used in
1417 subsequent CBCP phase.
1418 .Sh PPP OVER TCP and UDP (a.k.a Tunnelling)
1421 over a serial link, it is possible to
1422 use a TCP connection instead by specifying the host, port and protocol as the
1425 .Dl set device ui-gate:6669/tcp
1427 Instead of opening a serial device,
1429 will open a TCP connection to the given machine on the given
1431 It should be noted however that
1433 doesn't use the telnet protocol and will be unable to negotiate
1434 with a telnet server.
1435 You should set up a port for receiving this
1437 connection on the receiving machine (ui-gate).
1438 This is done by first updating
1440 to name the service:
1442 .Dl ppp-in 6669/tcp # Incoming PPP connections over TCP
1448 how to deal with incoming connections on that port:
1450 .Dl ppp-in stream tcp nowait root /usr/sbin/ppp ppp -direct ppp-in
1452 Don't forget to send a
1456 after you've updated
1457 .Pa /etc/inetd.conf .
1458 Here, we use a label named
1461 .Pa /etc/ppp/ppp.conf
1462 on ui-gate (the receiver) should contain the following:
1463 .Bd -literal -offset indent
1466 set ifaddr 10.0.4.1 10.0.4.2
1470 .Pa /etc/ppp/ppp.linkup
1472 .Bd -literal -offset indent
1474 add 10.0.1.0/24 HISADDR
1477 It is necessary to put the
1481 to ensure that the route is only added after
1483 has negotiated and assigned addresses to its interface.
1485 You may also want to enable PAP or CHAP for security.
1486 To enable PAP, add the following line:
1487 .Bd -literal -offset indent
1491 You'll also need to create the following entry in
1492 .Pa /etc/ppp/ppp.secret :
1493 .Bd -literal -offset indent
1494 MyAuthName MyAuthPasswd
1501 the password is looked up in the
1506 .Pa /etc/ppp/ppp.conf
1507 on awfulhak (the initiator) should contain the following:
1508 .Bd -literal -offset indent
1511 set device ui-gate:ppp-in/tcp
1514 set log Phase Chat Connect hdlc LCP IPCP IPV6CP CCP tun
1515 set ifaddr 10.0.4.2 10.0.4.1
1518 with the route setup in
1519 .Pa /etc/ppp/ppp.linkup :
1520 .Bd -literal -offset indent
1522 add 10.0.2.0/24 HISADDR
1525 Again, if you're enabling PAP, you'll also need this in the
1526 .Pa /etc/ppp/ppp.conf
1528 .Bd -literal -offset indent
1529 set authname MyAuthName
1530 set authkey MyAuthKey
1533 We're assigning the address of 10.0.4.1 to ui-gate, and the address
1534 10.0.4.2 to awfulhak.
1535 To open the connection, just type
1537 .Dl awfulhak # ppp -background ui-gate
1539 The result will be an additional "route" on awfulhak to the
1540 10.0.2.0/24 network via the TCP connection, and an additional
1541 "route" on ui-gate to the 10.0.1.0/24 network.
1542 The networks are effectively bridged - the underlying TCP
1543 connection may be across a public network (such as the
1546 traffic is conceptually encapsulated
1547 (although not packet by packet) inside the TCP stream between
1550 The major disadvantage of this mechanism is that there are two
1551 "guaranteed delivery" mechanisms in place - the underlying TCP
1552 stream and whatever protocol is used over the
1554 link - probably TCP again.
1555 If packets are lost, both levels will
1556 get in each others way trying to negotiate sending of the missing
1559 To avoid this overhead, it is also possible to do all this using
1560 UDP instead of TCP as the transport by simply changing the protocol
1561 from "tcp" to "udp".
1562 When using UDP as a transport,
1564 will operate in synchronous mode.
1565 This is another gain as the incoming
1566 data does not have to be rearranged into packets.
1568 Care should be taken when adding a default route through a tunneled
1570 It is quite common for the default route
1572 .Pa /etc/ppp/ppp.linkup )
1573 to end up routing the link's TCP connection through the tunnel,
1574 effectively garrotting the connection.
1575 To avoid this, make sure you add a static route for the benefit of
1577 .Bd -literal -offset indent
1580 set device ui-gate:ppp-in/tcp
1587 is the IP number that your route to
1591 When routing your connection accross a public network such as the Internet,
1592 it is preferable to encrypt the data.
1593 This can be done with the help of the MPPE protocol, although currently this
1594 means that you will not be able to also compress the traffic as MPPE is
1595 implemented as a compression layer (thank Microsoft for this).
1596 To enable MPPE encryption, add the following lines to
1597 .Pa /etc/ppp/ppp.conf
1599 .Bd -literal -offset indent
1601 disable deflate pred1
1605 ensuring that you've put the requisite entry in
1606 .Pa /etc/ppp/ppp.secret
1607 (MSCHAPv2 is challenge based, so
1611 MSCHAPv2 and MPPE are accepted by default, so the client end should work
1612 without any additional changes (although ensure you have
1617 .Sh NETWORK ADDRESS TRANSLATION (PACKET ALIASING)
1620 command line option enables network address translation (a.k.a. packet
1624 host to act as a masquerading gateway for other computers over
1625 a local area network.
1626 Outgoing IP packets are NAT'd so that they appear to come from the
1628 host, and incoming packets are de-NAT'd so that they are routed
1629 to the correct machine on the local area network.
1630 NAT allows computers on private, unregistered subnets to have Internet
1631 access, although they are invisible from the outside world.
1634 operation should first be verified with network address translation disabled.
1637 option should be switched on, and network applications (web browser,
1642 should be checked on the
1645 Finally, the same or similar applications should be checked on other
1646 computers in the LAN.
1647 If network applications work correctly on the
1649 host, but not on other machines in the LAN, then the masquerading
1650 software is working properly, but the host is either not forwarding
1651 or possibly receiving IP packets.
1652 Check that IP forwarding is enabled in
1654 and that other machines have designated the
1656 host as the gateway for the LAN.
1657 .Sh PACKET FILTERING
1658 This implementation supports packet filtering.
1659 There are four kinds of
1669 Here are the basics:
1672 A filter definition has the following syntax:
1681 .Ar src_addr Ns Op / Ns Ar width
1682 .Op Ar dst_addr Ns Op / Ns Ar width
1684 .Ar [ proto Op src Ar cmp port
1689 .Op timeout Ar secs ]
1701 is a numeric value between
1705 specifying the rule number.
1706 Rules are specified in numeric order according to
1717 in which case, if a given packet matches the rule, the associated action
1718 is taken immediately.
1720 can also be specified as
1722 to clear the action associated with that particular rule, or as a new
1723 rule number greater than the current rule.
1724 In this case, if a given
1725 packet matches the current rule, the packet will next be matched against
1726 the new rule number (rather than the next rule number).
1730 may optionally be followed with an exclamation mark
1734 to reverse the sense of the following match.
1736 .Op Ar src_addr Ns Op / Ns Ar width
1738 .Op Ar dst_addr Ns Op / Ns Ar width
1739 are the source and destination IP number specifications.
1742 is specified, it gives the number of relevant netmask bits,
1743 allowing the specification of an address range.
1749 may be given the values
1755 (refer to the description of the
1757 command for a description of these values).
1758 When these values are used,
1759 the filters will be updated any time the values change.
1760 This is similar to the behaviour of the
1765 may be any protocol from
1774 meaning less-than, equal and greater-than respectively.
1776 can be specified as a numeric port or by service name from
1784 flags are only allowed when
1788 and represent the TH_ACK, TH_SYN and TH_FIN or TH_RST TCP flags respectively.
1790 The timeout value adjusts the current idle timeout to at least
1793 If a timeout is given in the alive filter as well as in the in/out
1794 filter, the in/out value is used.
1795 If no timeout is given, the default timeout (set using
1797 and defaulting to 180 seconds) is used.
1801 Each filter can hold up to 40 rules, starting from rule 0.
1802 The entire rule set is not effective until rule 0 is defined,
1803 i.e., the default is to allow everything through.
1805 If no rule in a defined set of rules matches a packet, that packet will
1806 be discarded (blocked).
1807 If there are no rules in a given filter, the packet will be permitted.
1809 It's possible to filter based on the payload of UDP frames where those
1815 .Ar filter-decapsulation
1816 option below for further details.
1819 .Dq set filter Ar name No -1
1824 .Pa /usr/share/examples/ppp/ppp.conf.sample .
1825 .Sh SETTING THE IDLE TIMER
1826 To check/set the idle timer, use the
1831 .Bd -literal -offset indent
1832 ppp ON awfulhak> set timeout 600
1835 The timeout period is measured in seconds, the default value for which
1838 To disable the idle timer function, use the command
1839 .Bd -literal -offset indent
1840 ppp ON awfulhak> set timeout 0
1847 modes, the idle timeout is ignored.
1850 mode, when the idle timeout causes the
1855 program itself remains running.
1856 Another trigger packet will cause it to attempt to re-establish the link.
1857 .Sh PREDICTOR-1 and DEFLATE COMPRESSION
1859 supports both Predictor type 1 and deflate compression.
1862 will attempt to use (or be willing to accept) both compression protocols
1863 when the peer agrees
1865 The deflate protocol is preferred by
1871 commands if you wish to disable this functionality.
1873 It is possible to use a different compression algorithm in each direction
1874 by using only one of
1878 (assuming that the peer supports both algorithms).
1880 By default, when negotiating DEFLATE,
1882 will use a window size of 15.
1885 command if you wish to change this behaviour.
1887 A special algorithm called DEFLATE24 is also available, and is disabled
1888 and denied by default.
1889 This is exactly the same as DEFLATE except that
1890 it uses CCP ID 24 to negotiate.
1893 to successfully negotiate DEFLATE with
1896 .Sh CONTROLLING IP ADDRESS
1899 uses IPCP to negotiate IP addresses.
1900 Each side of the connection
1901 specifies the IP address that it's willing to use, and if the requested
1902 IP address is acceptable then
1904 returns an ACK to the requester.
1907 returns NAK to suggest that the peer use a different IP address.
1909 both sides of the connection agree to accept the received request (and
1910 send an ACK), IPCP is set to the open state and a network level connection
1912 To control this IPCP behaviour, this implementation has the
1914 command for defining the local and remote IP address:
1915 .Bd -ragged -offset indent
1916 .No set ifaddr Oo Ar src_addr Ns
1918 .Oo Ar dst_addr Ns Op / Ns Ar \&nn
1928 is the IP address that the local side is willing to use,
1930 is the IP address which the remote side should use and
1932 is the netmask that should be used.
1934 defaults to the current
1937 defaults to 0.0.0.0, and
1939 defaults to whatever mask is appropriate for
1941 It is only possible to make
1943 smaller than the default.
1944 The usual value is 255.255.255.255, as
1945 most kernels ignore the netmask of a POINTOPOINT interface.
1949 implementations require that the peer negotiates a specific IP
1952 If this is the case,
1954 may be used to specify this IP number.
1955 This will not affect the
1956 routing table unless the other side agrees with this proposed number.
1957 .Bd -literal -offset indent
1958 set ifaddr 192.244.177.38 192.244.177.2 255.255.255.255 0.0.0.0
1961 The above specification means:
1963 .Bl -bullet -compact
1965 I will first suggest that my IP address should be 0.0.0.0, but I
1966 will only accept an address of 192.244.177.38.
1968 I strongly insist that the peer uses 192.244.177.2 as his own
1969 address and won't permit the use of any IP address but 192.244.177.2.
1970 When the peer requests another IP address, I will always suggest that
1971 it uses 192.244.177.2.
1973 The routing table entry will have a netmask of 0xffffffff.
1976 This is all fine when each side has a pre-determined IP address, however
1977 it is often the case that one side is acting as a server which controls
1978 all IP addresses and the other side should go along with it.
1979 In order to allow more flexible behaviour, the
1981 command allows the user to specify IP addresses more loosely:
1983 .Dl set ifaddr 192.244.177.38/24 192.244.177.2/20
1985 A number followed by a slash
1987 represents the number of bits significant in the IP address.
1988 The above example means:
1990 .Bl -bullet -compact
1992 I'd like to use 192.244.177.38 as my address if it is possible, but I'll
1993 also accept any IP address between 192.244.177.0 and 192.244.177.255.
1995 I'd like to make him use 192.244.177.2 as his own address, but I'll also
1996 permit him to use any IP address between 192.244.176.0 and
1999 As you may have already noticed, 192.244.177.2 is equivalent to saying
2002 As an exception, 0 is equivalent to 0.0.0.0/0, meaning that I have no
2003 preferred IP address and will obey the remote peers selection.
2004 When using zero, no routing table entries will be made until a connection
2007 192.244.177.2/0 means that I'll accept/permit any IP address but I'll
2008 suggest that 192.244.177.2 be used first.
2011 When negotiating IPv6 addresses, no control is given to the user.
2012 IPV6CP negotiation is fully automatic.
2013 .Sh CONNECTING WITH YOUR INTERNET SERVICE PROVIDER
2014 The following steps should be taken when connecting to your ISP:
2017 Describe your providers phone number(s) in the dial script using the
2020 This command allows you to set multiple phone numbers for
2021 dialing and redialing separated by either a pipe
2025 .Bd -ragged -offset indent
2026 .No set phone Ar telno Ns Xo
2027 .Oo \&| Ns Ar backupnumber
2028 .Oc Ns ... Ns Oo : Ns Ar nextnumber
2033 Numbers after the first in a pipe-separated list are only used if the
2034 previous number was used in a failed dial or login script.
2036 separated by a colon are used sequentially, irrespective of what happened
2037 as a result of using the previous number.
2039 .Bd -literal -offset indent
2040 set phone "1234567|2345678:3456789|4567890"
2043 Here, the 1234567 number is attempted.
2044 If the dial or login script fails,
2045 the 2345678 number is used next time, but *only* if the dial or login script
2047 On the dial after this, the 3456789 number is used.
2049 number is only used if the dial or login script using the 3456789 fails.
2050 If the login script of the 2345678 number fails, the next number is still the
2052 As many pipes and colons can be used as are necessary
2053 (although a given site would usually prefer to use either the pipe or the
2054 colon, but not both).
2055 The next number redial timeout is used between all numbers.
2056 When the end of the list is reached, the normal redial period is
2057 used before starting at the beginning again.
2058 The selected phone number is substituted for the \\\\T string in the
2060 command (see below).
2062 Set up your redial requirements using
2064 For example, if you have a bad telephone line or your provider is
2065 usually engaged (not so common these days), you may want to specify
2067 .Bd -literal -offset indent
2071 This says that up to 4 phone calls should be attempted with a pause of 10
2072 seconds before dialing the first number again.
2074 Describe your login procedure using the
2081 command is used to talk to your modem and establish a link with your
2083 .Bd -literal -offset indent
2084 set dial "ABORT BUSY ABORT NO\\\\sCARRIER TIMEOUT 4 \\"\\" \e
2085 ATZ OK-ATZ-OK ATDT\\\\T TIMEOUT 60 CONNECT"
2088 This modem "chat" string means:
2091 Abort if the string "BUSY" or "NO CARRIER" are received.
2093 Set the timeout to 4 seconds.
2100 If that's not received within the 4 second timeout, send ATZ
2103 Send ATDTxxxxxxx where xxxxxxx is the next number in the phone list from
2106 Set the timeout to 60.
2108 Wait for the CONNECT string.
2111 Once the connection is established, the login script is executed.
2112 This script is written in the same style as the dial script, but care should
2113 be taken to avoid having your password logged:
2114 .Bd -literal -offset indent
2115 set authkey MySecret
2116 set login "TIMEOUT 15 login:-\\\\r-login: awfulhak \e
2117 word: \\\\P ocol: PPP HELLO"
2120 This login "chat" string means:
2123 Set the timeout to 15 seconds.
2126 If it's not received, send a carriage return and expect
2131 Expect "word:" (the tail end of a "Password:" prompt).
2133 Send whatever our current
2137 Expect "ocol:" (the tail end of a "Protocol:" prompt).
2146 command is logged specially.
2151 logging is enabled, the actual password is not logged;
2155 Login scripts vary greatly between ISPs.
2156 If you're setting one up for the first time,
2157 .Em ENABLE CHAT LOGGING
2158 so that you can see if your script is behaving as you expect.
2164 to specify your serial line and speed, for example:
2165 .Bd -literal -offset indent
2166 set device /dev/cuaa0
2170 Cuaa0 is the first serial port on
2177 A speed of 115200 should be specified
2178 if you have a modem capable of bit rates of 28800 or more.
2179 In general, the serial speed should be about four times the modem speed.
2183 command to {define} the IP address.
2186 If you know what IP address your provider uses, then use it as the remote
2187 address (dst_addr), otherwise choose something like 10.0.0.2/0 (see below).
2189 If your provider has assigned a particular IP address to you, then use
2190 it as your address (src_addr).
2192 If your provider assigns your address dynamically, choose a suitably
2193 unobtrusive and unspecific IP number as your address.
2194 10.0.0.1/0 would be appropriate.
2195 The bit after the / specifies how many bits of the
2196 address you consider to be important, so if you wanted to insist on
2197 something in the class C network 1.2.3.0, you could specify 1.2.3.1/24.
2199 If you find that your ISP accepts the first IP number that you suggest,
2200 specify third and forth arguments of
2202 This will force your ISP to assign a number.
2203 (The third argument will
2204 be ignored as it is less restrictive than the default mask for your
2208 An example for a connection where you don't know your IP number or your
2209 ISPs IP number would be:
2210 .Bd -literal -offset indent
2211 set ifaddr 10.0.0.1/0 10.0.0.2/0 0.0.0.0 0.0.0.0
2215 In most cases, your ISP will also be your default router.
2216 If this is the case, add the line
2217 .Bd -literal -offset indent
2222 .Pa /etc/ppp/ppp.conf
2224 .Pa /etc/ppp/ppp.linkup
2225 for setups that don't use
2231 to add a default route to whatever the peer address is
2232 (10.0.0.2 in this example).
2235 meaning that should the value of
2237 change, the route will be updated accordingly.
2239 If your provider requests that you use PAP/CHAP authentication methods, add
2240 the next lines to your
2241 .Pa /etc/ppp/ppp.conf
2243 .Bd -literal -offset indent
2245 set authkey MyPassword
2248 Both are accepted by default, so
2250 will provide whatever your ISP requires.
2252 It should be noted that a login script is rarely (if ever) required
2253 when PAP or CHAP are in use.
2255 Ask your ISP to authenticate your nameserver address(es) with the line
2256 .Bd -literal -offset indent
2262 do this if you are running a local DNS unless you also either use
2267 .Pa /etc/ppp/ppp.linkdown ,
2270 will simply circumvent its use by entering some nameserver lines in
2271 .Pa /etc/resolv.conf .
2275 .Pa /usr/share/examples/ppp/ppp.conf.sample
2277 .Pa /usr/share/examples/ppp/ppp.linkup.sample
2278 for some real examples.
2279 The pmdemand label should be appropriate for most ISPs.
2280 .Sh LOGGING FACILITY
2282 is able to generate the following log info either via
2284 or directly to the screen:
2286 .Bl -tag -width XXXXXXXXX -offset XXX -compact
2288 Enable all logging facilities.
2289 This generates a lot of log.
2290 The most common use of 'all' is as a basis, where you remove some facilities
2291 after enabling 'all' ('debug' and 'timer' are usually best disabled.)
2293 Dump async level packet in hex.
2295 Generate CBCP (CallBack Control Protocol) logs.
2297 Generate a CCP packet trace.
2305 chat script trace logs.
2307 Log commands executed either from the command line or any of the configuration
2310 Log Chat lines containing the string "CONNECT".
2312 Log debug information.
2314 Log DNS QUERY packets.
2316 Log packets permitted by the dial filter and denied by any filter.
2318 Dump HDLC packet in hex.
2320 Log all function calls specifically made as user id 0.
2322 Generate an IPCP packet trace.
2324 Generate an LCP packet trace.
2326 Generate LQR reports.
2328 Phase transition log output.
2330 Dump physical level packet in hex.
2332 Dump sync level packet in hex.
2334 Dump all TCP/IP packets.
2336 Log timer manipulation.
2338 Include the tun device on each log line.
2340 Output to the terminal device.
2341 If there is currently no terminal,
2342 output is sent to the log file using syslogs
2345 Output to both the terminal device
2346 and the log file using syslogs
2349 Output to the log file using
2355 command allows you to set the logging output level.
2356 Multiple levels can be specified on a single command line.
2357 The default is equivalent to
2360 It is also possible to log directly to the screen.
2361 The syntax is the same except that the word
2363 should immediately follow
2367 (i.e., only the un-maskable warning, error and alert output).
2369 If The first argument to
2370 .Dq set log Op local
2375 character, the current log levels are
2376 not cleared, for example:
2377 .Bd -literal -offset indent
2378 PPP ON awfulhak> set log phase
2379 PPP ON awfulhak> show log
2380 Log: Phase Warning Error Alert
2381 Local: Warning Error Alert
2382 PPP ON awfulhak> set log +tcp/ip -warning
2383 PPP ON awfulhak> set log local +command
2384 PPP ON awfulhak> show log
2385 Log: Phase TCP/IP Warning Error Alert
2386 Local: Command Warning Error Alert
2389 Log messages of level Warning, Error and Alert are not controllable
2391 .Dq set log Op local .
2395 level is special in that it will not be logged if it can be displayed
2399 deals with the following signals:
2400 .Bl -tag -width "USR2"
2402 Receipt of this signal causes the termination of the current connection
2406 to exit unless it is in
2411 .It HUP, TERM & QUIT
2418 to re-open any existing server socket, dropping all existing diagnostic
2420 Sockets that couldn't previously be opened will be retried.
2424 to close any existing server socket, dropping all existing diagnostic
2427 can still be used to re-open the socket.
2430 If you wish to use more than one physical link to connect to a
2432 peer, that peer must also understand the
2435 Refer to RFC 1990 for specification details.
2437 The peer is identified using a combination of his
2438 .Dq endpoint discriminator
2440 .Dq authentication id .
2441 Either or both of these may be specified.
2442 It is recommended that
2443 at least one is specified, otherwise there is no way of ensuring that
2444 all links are actually connected to the same peer program, and some
2445 confusing lock-ups may result.
2446 Locally, these identification variables are specified using the
2455 must be agreed in advance with the peer.
2457 Multi-link capabilities are enabled using the
2459 command (set maximum reconstructed receive unit).
2460 Once multi-link is enabled,
2462 will attempt to negotiate a multi-link connection with the peer.
2464 By default, only one
2469 To create more links, the
2472 This command will clone existing links, where all
2473 characteristics are the same except:
2476 The new link has its own name as specified on the
2483 Its mode may subsequently be changed using the
2487 The new link is in a
2492 A summary of all available links can be seen using the
2496 Once a new link has been created, command usage varies.
2497 All link specific commands must be prefixed with the
2499 command, specifying on which link the command is to be applied.
2500 When only a single link is available,
2502 is smart enough not to require the
2506 Some commands can still be used without specifying a link - resulting
2507 in an operation at the
2510 For example, once two or more links are available, the command
2512 will show CCP configuration and statistics at the multi-link level, and
2513 .Dq link deflink show ccp
2514 will show the same information at the
2518 Armed with this information, the following configuration might be used:
2520 .Bd -literal -offset indent
2524 set device /dev/cuaa0 /dev/cuaa1 /dev/cuaa2
2525 set phone "123456789"
2526 set dial "ABORT BUSY ABORT NO\\sCARRIER TIMEOUT 5 \\"\\" ATZ \e
2527 OK-AT-OK \\\\dATDT\\\\T TIMEOUT 45 CONNECT"
2529 set ifaddr 10.0.0.1/0 10.0.0.2/0 0.0.0.0 0.0.0.0
2531 set authkey ppppassword
2534 clone 1,2,3 # Create 3 new links - duplicates of the default
2535 link deflink remove # Delete the default link (called ``deflink'')
2538 Note how all cloning is done at the end of the configuration.
2539 Usually, the link will be configured first, then cloned.
2540 If you wish all links
2541 to be up all the time, you can add the following line to the end of your
2544 .Bd -literal -offset indent
2545 link 1,2,3 set mode ddial
2548 If you want the links to dial on demand, this command could be used:
2550 .Bd -literal -offset indent
2551 link * set mode auto
2554 Links may be tied to specific names by removing the
2556 line above, and specifying the following after the
2560 .Bd -literal -offset indent
2561 link 1 set device /dev/cuaa0
2562 link 2 set device /dev/cuaa1
2563 link 3 set device /dev/cuaa2
2568 command to see which commands require context (using the
2570 command), which have optional
2571 context and which should not have any context.
2577 mode with the peer, it creates a local domain socket in the
2580 This socket is used to pass link information (including
2581 the actual link file descriptor) between different
2586 ability to be run from a
2592 capability), without needing to have initial control of the serial
2596 negotiates multi-link mode, it will pass its open link to any
2597 already running process.
2598 If there is no already running process,
2600 will act as the master, creating the socket and listening for new
2602 .Sh PPP COMMAND LIST
2603 This section lists the available commands and their effect.
2604 They are usable either from an interactive
2606 session, from a configuration file or from a
2612 .It accept|deny|enable|disable Ar option....
2613 These directives tell
2615 how to negotiate the initial connection with the peer.
2618 has a default of either accept or deny and enable or disable.
2620 means that the option will be ACK'd if the peer asks for it.
2622 means that the option will be NAK'd if the peer asks for it.
2624 means that the option will be requested by us.
2626 means that the option will not be requested by us.
2629 may be one of the following:
2632 Default: Enabled and Accepted.
2633 ACFComp stands for Address and Control Field Compression.
2634 Non LCP packets will usually have an address
2635 field of 0xff (the All-Stations address) and a control field of
2636 0x03 (the Unnumbered Information command).
2638 negotiated, these two bytes are simply not sent, thus minimising
2645 Default: Disabled and Accepted.
2646 CHAP stands for Challenge Handshake Authentication Protocol.
2647 Only one of CHAP and PAP (below) may be negotiated.
2648 With CHAP, the authenticator sends a "challenge" message to its peer.
2649 The peer uses a one-way hash function to encrypt the
2650 challenge and sends the result back.
2651 The authenticator does the same, and compares the results.
2652 The advantage of this mechanism is that no
2653 passwords are sent across the connection.
2654 A challenge is made when the connection is first made.
2655 Subsequent challenges may occur.
2656 If you want to have your peer authenticate itself, you must
2659 .Pa /etc/ppp/ppp.conf ,
2660 and have an entry in
2661 .Pa /etc/ppp/ppp.secret
2664 When using CHAP as the client, you need only specify
2669 .Pa /etc/ppp/ppp.conf .
2670 CHAP is accepted by default.
2673 implementations use "MS-CHAP" rather than MD5 when encrypting the
2675 MS-CHAP is a combination of MD4 and DES.
2678 was built on a machine with DES libraries available, it will respond
2679 to MS-CHAP authentication requests, but will never request them.
2681 Default: Enabled and Accepted.
2682 This option decides if deflate
2683 compression will be used by the Compression Control Protocol (CCP).
2684 This is the same algorithm as used by the
2687 Note: There is a problem negotiating
2693 implementation available under many operating systems.
2695 (version 2.3.1) incorrectly attempts to negotiate
2697 compression using type
2699 as the CCP configuration type rather than type
2705 is actually specified as
2706 .Dq PPP Magna-link Variable Resource Compression
2710 is capable of negotiating with
2717 .Ar accept Ns No ed .
2719 Default: Disabled and Denied.
2720 This is a variance of the
2722 option, allowing negotiation with the
2727 section above for details.
2728 It is disabled by default as it violates
2731 Default: Disabled and Denied.
2732 This option allows DNS negotiation.
2737 will request that the peer confirms the entries in
2738 .Pa /etc/resolv.conf .
2739 If the peer NAKs our request (suggesting new IP numbers),
2740 .Pa /etc/resolv.conf
2741 is updated and another request is sent to confirm the new entries.
2744 .Dq accept Ns No ed,
2746 will answer any DNS queries requested by the peer rather than rejecting
2748 The answer is taken from
2749 .Pa /etc/resolv.conf
2752 command is used as an override.
2754 Default: Enabled and Accepted.
2755 This option allows control over whether we
2756 negotiate an endpoint discriminator.
2757 We only send our discriminator if
2762 We reject the peers discriminator if
2766 Default: Disabled and Accepted.
2767 The use of this authentication protocol
2768 is discouraged as it partially violates the authentication protocol by
2769 implementing two different mechanisms (LANMan & NT) under the guise of
2770 a single CHAP type (0x80).
2772 uses a simple DES encryption mechanism and is the least secure of the
2773 CHAP alternatives (although is still more secure than PAP).
2777 description below for more details.
2779 Default: Disabled and Accepted.
2780 This option decides if Link Quality Requests will be sent or accepted.
2781 LQR is a protocol that allows
2783 to determine that the link is down without relying on the modems
2785 When LQR is enabled,
2791 below) as part of the LCP request.
2792 If the peer agrees, both sides will
2793 exchange LQR packets at the agreed frequency, allowing detailed link
2794 quality monitoring by enabling LQM logging.
2795 If the peer doesn't agree,
2797 will send ECHO LQR requests instead.
2798 These packets pass no information of interest, but they
2800 be replied to by the peer.
2802 Whether using LQR or ECHO LQR,
2804 will abruptly drop the connection if 5 unacknowledged packets have been
2805 sent rather than sending a 6th.
2806 A message is logged at the
2808 level, and any appropriate
2810 values are honoured as if the peer were responsible for dropping the
2813 Default: Enabled and Accepted.
2814 This is Microsoft Point to Point Encryption scheme.
2815 MPPE key size can be
2816 40-, 56- and 128-bits.
2821 Default: Disabled and Accepted.
2822 It is very similar to standard CHAP (type 0x05)
2823 except that it issues challenges of a fixed 16 bytes in length and uses a
2824 combination of MD4, SHA-1 and DES to encrypt the challenge rather than using the
2825 standard MD5 mechanism.
2827 Default: Disabled and Accepted.
2828 The use of this authentication protocol
2829 is discouraged as it partially violates the authentication protocol by
2830 implementing two different mechanisms (LANMan & NT) under the guise of
2831 a single CHAP type (0x80).
2832 It is very similar to standard CHAP (type 0x05)
2833 except that it issues challenges of a fixed 8 bytes in length and uses a
2834 combination of MD4 and DES to encrypt the challenge rather than using the
2835 standard MD5 mechanism.
2836 CHAP type 0x80 for LANMan is also supported - see
2844 use CHAP type 0x80, when acting as authenticator with both
2845 .Dq enable Ns No d ,
2847 will rechallenge the peer up to three times if it responds using the wrong
2848 one of the two protocols.
2849 This gives the peer a chance to attempt using both protocols.
2853 acts as the authenticatee with both protocols
2854 .Dq accept Ns No ed ,
2855 the protocols are used alternately in response to challenges.
2857 Note: If only LANMan is enabled,
2859 (version 2.3.5) misbehaves when acting as authenticatee.
2861 the NT and the LANMan answers, but also suggests that only the NT answer
2864 Default: Disabled and Accepted.
2865 PAP stands for Password Authentication Protocol.
2866 Only one of PAP and CHAP (above) may be negotiated.
2867 With PAP, the ID and Password are sent repeatedly to the peer until
2868 authentication is acknowledged or the connection is terminated.
2869 This is a rather poor security mechanism.
2870 It is only performed when the connection is first established.
2871 If you want to have your peer authenticate itself, you must
2874 .Pa /etc/ppp/ppp.conf ,
2875 and have an entry in
2876 .Pa /etc/ppp/ppp.secret
2877 for the peer (although see the
2883 When using PAP as the client, you need only specify
2888 .Pa /etc/ppp/ppp.conf .
2889 PAP is accepted by default.
2891 Default: Enabled and Accepted.
2892 This option decides if Predictor 1
2893 compression will be used by the Compression Control Protocol (CCP).
2895 Default: Enabled and Accepted.
2896 This option is used to negotiate
2897 PFC (Protocol Field Compression), a mechanism where the protocol
2898 field number is reduced to one octet rather than two.
2900 Default: Enabled and Accepted.
2901 This option determines if
2903 will request and accept requests for short
2905 sequence numbers when negotiating multi-link mode.
2906 This is only applicable if our MRRU is set (thus enabling multi-link).
2908 Default: Enabled and Accepted.
2909 This option determines if Van Jacobson header compression will be used.
2912 The following options are not actually negotiated with the peer.
2913 Therefore, accepting or denying them makes no sense.
2915 .It filter-decapsulation
2917 When this option is enabled,
2919 will examine UDP frames to see if they actually contain a
2921 frame as their payload.
2922 If this is the case, all filters will operate on the payload rather
2923 than the actual packet.
2925 This is useful if you want to send PPPoUDP traffic over a
2927 link, but want that link to do smart things with the real data rather than
2930 The UDP frame payload must not be compressed in any way, otherwise
2932 will not be able to interpret it.
2933 It's therefore recommended that you
2934 .Ic disable vj pred1 deflate
2936 .Ic deny vj pred1 deflate
2937 in the configuration for the
2939 invocation with the udp link.
2944 exchanges low-level LCP, CCP and IPCP configuration traffic, the
2946 field of any replies is expected to be the same as that of the request.
2949 drops any reply packets that do not contain the expected identifier
2950 field, reporting the fact at the respective log level.
2955 will ignore the identifier field.
2960 This option simply tells
2962 to add new interface addresses to the interface rather than replacing them.
2963 The option can only be enabled if network address translation is enabled
2964 .Pq Dq nat enable yes .
2966 With this option enabled,
2968 will pass traffic for old interface addresses through the NAT
2969 ifdef({LOCALNAT},{engine,},{engine
2971 .Xr libalias 3 ) ,})
2972 resulting in the ability (in
2974 mode) to properly connect the process that caused the PPP link to
2975 come up in the first place.
2985 to attempt to negotiate IP control protocol capabilities and if
2986 successful to exchange IP datagrams with the peer.
2991 to attempt to negotiate IPv6 control protocol capabilities and if
2992 successful to exchange IPv6 datagrams with the peer.
2997 runs as a Multi-link server, a different
2999 instance initially receives each connection.
3000 After determining that
3001 the link belongs to an already existing bundle (controlled by another
3005 will transfer the link to that process.
3007 If the link is a tty device or if this option is enabled,
3009 will not exit, but will change its process name to
3011 and wait for the controlling
3013 to finish with the link and deliver a signal back to the idle process.
3014 This prevents the confusion that results from
3016 parent considering the link resource available again.
3018 For tty devices that have entries in
3020 this is necessary to prevent another
3022 from being started, and for program links such as
3026 from exiting due to the death of its child.
3029 cannot determine its parents requirements (except for the tty case), this
3030 option must be enabled manually depending on the circumstances.
3037 will automatically loop back packets being sent
3038 out with a destination address equal to that of the
3043 will send the packet, probably resulting in an ICMP redirect from
3045 It is convenient to have this option enabled when
3046 the interface is also the default route as it avoids the necessity
3047 of a loopback route.
3050 Enabling this option will tell the PAP authentication
3051 code to use the password database (see
3053 to authenticate the caller if they cannot be found in the
3054 .Pa /etc/ppp/ppp.secret
3056 .Pa /etc/ppp/ppp.secret
3057 is always checked first.
3058 If you wish to use passwords from
3060 but also to specify an IP number or label for a given client, use
3062 as the client password in
3063 .Pa /etc/ppp/ppp.secret .
3066 Enabling this option will tell
3068 to proxy ARP for the peer.
3071 will make an entry in the ARP table using
3075 address of the local network in which
3078 This allows other machines connecteed to the LAN to talk to
3079 the peer as if the peer itself was connected to the LAN.
3080 The proxy entry cannot be made unless
3082 is an address from a LAN.
3085 Enabling this will tell
3087 to add proxy arp entries for every IP address in all class C or
3088 smaller subnets routed via the tun interface.
3090 Proxy arp entries are only made for sticky routes that are added
3094 No proxy arp entries are made for the interface address itself
3102 command is used with the
3108 values, entries are stored in the
3111 Each time these variables change, this list is re-applied to the routing table.
3113 Disabling this option will prevent the re-application of sticky routes,
3116 list will still be maintained.
3123 to adjust TCP SYN packets so that the maximum receive segment
3124 size is not greater than the amount allowed by the interface MTU.
3129 to gather throughput statistics.
3130 Input and output is sampled over
3131 a rolling 5 second window, and current, best and total figures are retained.
3132 This data is output when the relevant
3134 layer shuts down, and is also available using the
3137 Throughput statistics are available at the
3144 Normally, when a user is authenticated using PAP or CHAP, and when
3148 mode, an entry is made in the utmp and wtmp files for that user.
3149 Disabling this option will tell
3151 not to make any utmp or wtmp entries.
3152 This is usually only necessary if
3153 you require the user to both login and authenticate themselves.
3158 .Ar dest Ns Op / Ns Ar nn
3163 is the destination IP address.
3164 The netmask is specified either as a number of bits with
3166 or as an IP number using
3171 with no mask refers to the default route.
3172 It is also possible to use the literal name
3177 is the next hop gateway to get to the given
3182 command for further details.
3184 It is possible to use the symbolic names
3190 as the destination, and
3197 is replaced with the interface IP address,
3199 is replaced with the interface IP destination (peer) address,
3201 is replaced with the interface IPv6 address, and
3203 is replaced with the interface IPv6 destination address,
3210 then if the route already exists, it will be updated as with the
3214 for further details).
3216 Routes that contain the
3224 constants are considered
3226 They are stored in a list (use
3228 to see the list), and each time the value of one of these variables
3229 changes, the appropriate routing table entries are updated.
3230 This facility may be disabled using
3231 .Dq disable sroutes .
3232 .It allow Ar command Op Ar args
3233 This command controls access to
3235 and its configuration files.
3236 It is possible to allow user-level access,
3237 depending on the configuration file label and on the mode that
3240 For example, you may wish to configure
3250 User id 0 is immune to these commands.
3252 .It allow user Ns Xo
3254 .Ar logname Ns No ...
3256 By default, only user id 0 is allowed access to
3258 If this command is used, all of the listed users are allowed access to
3259 the section in which the
3264 section is always checked first (even though it is only ever automatically
3267 commands are cumulative in a given section, but users allowed in any given
3268 section override users allowed in the default section, so it's possible to
3269 allow users access to everything except a given label by specifying default
3272 section, and then specifying a new user list for that label.
3276 is specified, access is allowed to all users.
3277 .It allow mode Ns Xo
3281 By default, access using any
3284 If this command is used, it restricts the access
3286 allowed to load the label under which this command is specified.
3291 command overrides any previous settings, and the
3293 section is always checked first.
3305 When running in multi-link mode, a section can be loaded if it allows
3307 of the currently existing line modes.
3310 .It nat Ar command Op Ar args
3311 This command allows the control of the network address translation (also
3312 known as masquerading or IP aliasing) facilities that are built into
3314 NAT is done on the external interface only, and is unlikely to make sense
3319 If nat is enabled on your system (it may be omitted at compile time),
3320 the following commands are possible:
3322 .It nat enable yes|no
3323 This command either switches network address translation on or turns it off.
3326 command line flag is synonymous with
3327 .Dq nat enable yes .
3328 .It nat addr Op Ar addr_local addr_alias
3329 This command allows data for
3333 It is useful if you own a small number of real IP numbers that
3334 you wish to map to specific machines behind your gateway.
3335 .It nat deny_incoming yes|no
3336 If set to yes, this command will refuse all incoming packets where an
3337 aliasing link doesn't already exist.
3338 ifdef({LOCALNAT},{},{Refer to the
3339 .Sx CONCEPTUAL BACKGROUND
3342 for a description of what an
3347 It should be noted under what circumstances an aliasing link is
3348 ifdef({LOCALNAT},{created.},{created by
3350 It may be necessary to further protect your network from outside
3351 connections using the
3357 This command gives a summary of available nat commands.
3359 This option causes various NAT statistics and information to
3360 be logged to the file
3361 .Pa /var/log/alias.log .
3362 .It nat port Ar proto Ar targetIP Ns Xo
3363 .No : Ns Ar targetPort Ns
3365 .No - Ns Ar targetPort
3368 .No - Ns Ar aliasPort
3369 .Oc Oo Ar remoteIP : Ns
3372 .No - Ns Ar remotePort
3376 This command causes incoming
3390 A range of port numbers may be specified as shown above.
3391 The ranges must be of the same size.
3395 is specified, only data coming from that IP number is redirected.
3399 (indicating any source port)
3400 or a range of ports the same size as the other ranges.
3402 This option is useful if you wish to run things like Internet phone on
3403 machines behind your gateway, but is limited in that connections to only
3404 one interior machine per source machine and target port are possible.
3405 .It nat proto Ar proto localIP Oo
3406 .Ar publicIP Op Ar remoteIP
3410 to redirect packets of protocol type
3414 to the internal address
3419 is specified, only packets destined for that address are matched,
3420 otherwise the default alias address is used.
3424 is specified, only packets matching that source address are matched,
3426 This command is useful for redirecting tunnel endpoints to an internal machine,
3429 .Dl nat proto ipencap 10.0.0.1
3430 .It "nat proxy cmd" Ar arg Ns No ...
3433 to proxy certain connections, redirecting them to a given server.
3434 ifdef({LOCALNAT},{},{Refer to the description of
3435 .Fn PacketAliasProxyRule
3438 for details of the available commands.
3440 .It nat punch_fw Op Ar base count
3443 to punch holes in the firewall for FTP or IRC DCC connections.
3444 This is done dynamically by installing termporary firewall rules which
3445 allow a particular connection (and only that connection) to go through
3447 The rules are removed once the corresponding connection terminates.
3451 rules starting from rule number
3453 will be used for punching firewall holes.
3454 The range will be cleared when the
3458 If no arguments are given, firewall punching is disabled.
3459 .It nat same_ports yes|no
3460 When enabled, this command will tell the network address translation engine to
3461 attempt to avoid changing the port number on outgoing packets.
3463 if you want to support protocols such as RPC and LPD which require
3464 connections to come from a well known port.
3465 .It nat target Op Ar address
3466 Set the given target address or clear it if no address is given.
3467 The target address is used
3468 ifdef({LOCALNAT},{},{by libalias })dnl
3469 to specify how to NAT incoming packets by default.
3470 If a target address is not set or if
3472 is given, packets are not altered and are allowed to route to the internal
3475 The target address may be set to
3478 ifdef({LOCALNAT},{all packets will be redirected},
3479 {libalias will redirect all packets})
3480 to the interface address.
3481 .It nat use_sockets yes|no
3482 When enabled, this option tells the network address translation engine to
3483 create a socket so that it can guarantee a correct incoming ftp data or
3485 .It nat unregistered_only yes|no
3486 Only alter outgoing packets with an unregistered source address.
3487 According to RFC 1918, unregistered source addresses
3488 are 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16.
3491 These commands are also discussed in the file
3493 which comes with the source distribution.
3500 is executed in the background with the following words replaced:
3501 .Bl -tag -width COMPILATIONDATE
3503 This is replaced with the local
3509 .It Li COMPILATIONDATE
3510 This is replaced with the date on which
3514 These are replaced with the primary and secondary nameserver IP numbers.
3515 If nameservers are negotiated by IPCP, the values of these macros will change.
3517 This is replaced with the local endpoint discriminator value.
3522 This is replaced with the peers IP number.
3524 This is replaced with the peers IPv6 number.
3526 This is replaced with the name of the interface that's in use.
3528 This is replaced with the number of IP bytes received since the connection
3531 This is replaced with the number of IP bytes sent since the connection
3534 This is replaced with the number of IP packets received since the connection
3537 This is replaced with the number of IP packets sent since the connection
3540 This is replaced with the number of IPv6 bytes received since the connection
3542 .It Li IPV6OCTETSOUT
3543 This is replaced with the number of IPv6 bytes sent since the connection
3545 .It Li IPV6PACKETSIN
3546 This is replaced with the number of IPv6 packets received since the connection
3548 .It Li IPV6PACKETSOUT
3549 This is replaced with the number of IPv6 packets sent since the connection
3552 This is replaced with the last label name used.
3553 A label may be specified on the
3555 command line, via the
3563 This is replaced with the IP number assigned to the local interface.
3565 This is replaced with the IPv6 number assigned to the local interface.
3567 This is replaced with the number of bytes received since the connection
3570 This is replaced with the number of bytes sent since the connection
3573 This is replaced with the number of packets received since the connection
3576 This is replaced with the number of packets sent since the connection
3579 This is replaced with the value of the peers endpoint discriminator.
3581 This is replaced with the current process id.
3583 This is replaced with the name of the diagnostic socket.
3585 This is replaced with the bundle uptime in HH:MM:SS format.
3587 This is replaced with the username that has been authenticated with PAP or
3589 Normally, this variable is assigned only in -direct mode.
3590 This value is available irrespective of whether utmp logging is enabled.
3592 This is replaced with the current version number of
3596 These substitutions are also done by the
3603 If you wish to pause
3605 while the command executes, use the
3608 .It clear physical|ipcp|ipv6 Op current|overall|peak...
3609 Clear the specified throughput values at either the
3617 is specified, context must be given (see the
3620 If no second argument is given, all values are cleared.
3621 .It clone Ar name Ns Xo
3622 .Op \&, Ns Ar name Ns
3625 Clone the specified link, creating one or more new links according to the
3628 This command must be used from the
3630 command below unless you've only got a single link (in which case that
3631 link becomes the default).
3632 Links may be removed using the
3636 The default link name is
3638 .It close Op lcp|ccp Ns Op !\&
3639 If no arguments are given, the relevant protocol layers will be brought
3640 down and the link will be closed.
3643 is specified, the LCP layer is brought down, but
3645 will not bring the link offline.
3646 It is subsequently possible to use
3649 to talk to the peer machine if, for example, something like
3654 is specified, only the relevant compression layer is closed.
3657 is used, the compression layer will remain in the closed state, otherwise
3658 it will re-enter the STOPPED state, waiting for the peer to initiate
3659 further CCP negotiation.
3660 In any event, this command does not disconnect the user from
3671 This command deletes the route with the given
3678 all non-direct entries in the routing table for the current interface,
3681 entries are deleted.
3686 the default route is deleted.
3694 will not complain if the route does not already exist.
3695 .It dial|call Op Ar label Ns Xo
3698 This command is the equivalent of
3702 and is provided for backwards compatibility.
3703 .It down Op Ar lcp|ccp
3704 Bring the relevant layer down ungracefully, as if the underlying layer
3705 had become unavailable.
3706 It's not considered polite to use this command on
3707 a Finite State Machine that's in the OPEN state.
3709 supplied, the entire link is closed (or if no context is given, all links
3715 layer is terminated but the device is not brought offline and the link
3719 is specified, only the relevant compression layer(s) are terminated.
3720 .It help|? Op Ar command
3721 Show a list of available commands.
3724 is specified, show the usage string for that command.
3725 .It ident Op Ar text Ns No ...
3726 Identify the link to the peer using
3730 is empty, link identification is disabled.
3731 It is possible to use any of the words described for the
3736 command for details of when
3738 identifies itself to the peer.
3739 .It iface Ar command Op args
3740 This command is used to control the interface used by
3743 may be one of the following:
3747 .Ar addr Ns Op / Ns Ar bits
3758 combination to the interface.
3759 Instead of specifying
3763 (with no space between it and
3765 If the given address already exists, the command fails unless the
3767 is used - in which case the previous interface address entry is overwritten
3768 with the new one, allowing a change of netmask or peer address.
3779 .Dq 255.255.255.255 .
3780 This address (the broadcast address) is the only duplicate peer address that
3783 .It iface clear Op INET | INET6
3784 If this command is used while
3786 is in the OPENED state or while in
3788 mode, all addresses except for the NCP negotiated address are deleted
3792 is not in the OPENED state and is not in
3794 mode, all interface addresses are deleted.
3796 If the INET or INET6 arguments are used, only addresses for that address
3799 .It iface delete Ns Xo
3804 This command deletes the given
3809 is used, no error is given if the address isn't currently assigned to
3810 the interface (and no deletion takes place).
3812 Shows the current state and current addresses for the interface.
3813 It is much the same as running
3814 .Dq ifconfig INTERFACE .
3815 .It iface help Op Ar sub-command
3816 This command, when invoked without
3818 will show a list of possible
3820 sub-commands and a brief synopsis for each.
3823 only the synopsis for the given sub-command is shown.
3827 .Ar name Ns Op , Ns Ar name Ns
3828 .No ... Ar command Op Ar args
3830 This command may prefix any other command if the user wishes to
3831 specify which link the command should affect.
3832 This is only applicable after multiple links have been created in Multi-link
3838 specifies the name of an existing link.
3841 is a comma separated list,
3843 is executed on each link.
3849 is executed on all links.
3850 .It load Op Ar label Ns Xo
3873 will not attempt to make an immediate connection.
3874 .It log Ar word Ns No ...
3875 Send the given word(s) to the log file with the prefix
3877 Word substitutions are done as explained under the
3880 .It open Op lcp|ccp|ipcp
3881 This is the opposite of the
3884 All closed links are immediately brought up apart from second and subsequent
3886 links - these will come up based on the
3888 command that has been used.
3892 argument is used while the LCP layer is already open, LCP will be
3894 This allows various LCP options to be changed, after which
3896 can be used to put them into effect.
3897 After renegotiating LCP,
3898 any agreed authentication will also take place.
3902 argument is used, the relevant compression layer is opened.
3903 Again, if it is already open, it will be renegotiated.
3907 argument is used, the link will be brought up as normal, but if
3908 IPCP is already open, it will be renegotiated and the network
3909 interface will be reconfigured.
3911 It is probably not good practice to re-open the PPP state machines
3912 like this as it's possible that the peer will not behave correctly.
3915 however useful as a way of forcing the CCP or VJ dictionaries to be reset.
3917 Specify the password required for access to the full
3920 This password is required when connecting to the diagnostic port (see the
3931 logging is active, instead, the literal string
3937 is executed from the controlling connection or from a command file,
3938 ppp will exit after closing all connections.
3939 Otherwise, if the user
3940 is connected to a diagnostic socket, the connection is simply dropped.
3946 will exit despite the source of the command after closing all existing
3949 This command removes the given link.
3950 It is only really useful in multi-link mode.
3951 A link must be in the
3953 state before it is removed.
3954 .It rename|mv Ar name
3955 This command renames the given link to
3959 is already used by another link.
3961 The default link name is
3968 may make the log file more readable.
3969 .It resolv Ar command
3970 This command controls
3977 starts up, it loads the contents of this file into memory and retains this
3978 image for future use.
3980 is one of the following:
3981 .Bl -tag -width readonly
3984 .Pa /etc/resolv.conf
3990 will still attempt to negotiate nameservers with the peer, making the results
3996 This is the opposite of the
4001 .Pa /etc/resolv.conf
4003 This may be necessary if for example a DHCP client overwrote
4004 .Pa /etc/resolv.conf .
4007 .Pa /etc/resolv.conf
4008 with the version originally read at startup or with the last
4011 This is sometimes a useful command to put in the
4012 .Pa /etc/ppp/ppp.linkdown
4016 .Pa /etc/resolv.conf
4018 This command will work even if the
4020 command has been used.
4021 It may be useful as a command in the
4022 .Pa /etc/ppp/ppp.linkup
4023 file if you wish to defer updating
4024 .Pa /etc/resolv.conf
4025 until after other commands have finished.
4030 .Pa /etc/resolv.conf
4035 successfully negotiates a DNS.
4036 This is the opposite of the
4041 This option is not (yet) implemented.
4045 to identify itself to the peer.
4046 The link must be in LCP state or higher.
4047 If no identity has been set (via the
4053 When an identity has been set,
4055 will automatically identify itself when it sends or receives a configure
4056 reject, when negotiation fails or when LCP reaches the opened state.
4058 Received identification packets are logged to the LCP log (see
4060 for details) and are never responded to.
4065 This option allows the setting of any of the following variables:
4067 .It set accmap Ar hex-value
4068 ACCMap stands for Asynchronous Control Character Map.
4070 negotiated with the peer, and defaults to a value of 00000000 in hex.
4071 This protocol is required to defeat hardware that depends on passing
4072 certain characters from end to end (such as XON/XOFF etc).
4074 For the XON/XOFF scenario, use
4075 .Dq set accmap 000a0000 .
4076 .It set Op auth Ns Xo
4079 This sets the authentication key (or password) used in client mode
4080 PAP or CHAP negotiation to the given value.
4081 It also specifies the
4082 password to be used in the dial or login scripts in place of the
4084 sequence, preventing the actual password from being logged.
4089 logging is in effect,
4093 for security reasons.
4095 If the first character of
4097 is an exclamation mark
4100 treats the remainder of the string as a program that must be executed
4112 it is treated as a single literal
4114 otherwise, ignoring the
4117 is parsed as a program to execute in the same was as the
4119 command above, substituting special names in the same manner.
4122 will feed the program three lines of input, each terminated by a newline
4126 The host name as sent in the CHAP challenge.
4128 The challenge string as sent in the CHAP challenge.
4134 Two lines of output are expected:
4139 to be sent with the CHAP response.
4143 which is encrypted with the challenge and request id, the answer being sent
4144 in the CHAP response packet.
4149 in this manner, it's expected that the host challenge is a series of ASCII
4150 digits or characters.
4151 An encryption device or Secure ID card is usually
4152 required to calculate the secret appropriate for the given challenge.
4153 .It set authname Ar id
4154 This sets the authentication id used in client mode PAP or CHAP negotiation.
4158 mode with CHAP enabled,
4160 is used in the initial authentication challenge and should normally be set to
4161 the local machine name.
4163 .Ar min-percent max-percent period
4165 These settings apply only in multi-link mode and default to zero, zero and
4171 mode link is available, only the first link is made active when
4173 first reads data from the tun device.
4176 link will be opened only when the current bundle throughput is at least
4178 percent of the total bundle bandwidth for
4181 When the current bundle throughput decreases to
4183 percent or less of the total bundle bandwidth for
4187 link will be brought down as long as it's not the last active link.
4189 Bundle throughput is measured as the maximum of inbound and outbound
4192 The default values cause
4194 links to simply come up one at a time.
4196 Certain devices cannot determine their physical bandwidth, so it
4197 is sometimes necessary to use the
4199 command (described below) to make
4202 .It set bandwidth Ar value
4203 This command sets the connection bandwidth in bits per second.
4205 must be greater than zero.
4206 It is currently only used by the
4209 .It set callback Ar option Ns No ...
4210 If no arguments are given, callback is disabled, otherwise,
4214 mode, will accept) one of the given
4215 .Ar option Ns No s .
4216 In client mode, if an
4220 will request a different
4222 until no options remain at which point
4224 will terminate negotiations (unless
4226 is one of the specified
4230 will accept any of the given protocols - but the client
4232 request one of them.
4233 If you wish callback to be optional, you must {include}
4239 are as follows (in this order of preference):
4243 The callee is expected to decide the callback number based on
4247 is the callee, the number should be specified as the fifth field of
4249 .Pa /etc/ppp/ppp.secret .
4251 Microsoft's callback control protocol is used.
4256 If you wish to negotiate
4258 in client mode but also wish to allow the server to request no callback at
4259 CBCP negotiation time, you must specify both
4263 as callback options.
4265 .Ar number Ns Op , Ns Ar number Ns
4268 The caller specifies the
4274 should be either a comma separated list of allowable numbers or a
4276 meaning any number is permitted.
4279 is the caller, only a single number should be specified.
4281 Note, this option is very unsafe when used with a
4283 as a malicious caller can tell
4285 to call any (possibly international) number without first authenticating
4288 If the peer does not wish to do callback at all,
4290 will accept the fact and continue without callback rather than terminating
4292 This is required (in addition to one or more other callback
4293 options) if you wish callback to be optional.
4297 .No *| Ns Ar number Ns Oo
4298 .No , Ns Ar number Ns ...\& Oc
4299 .Op Ar delay Op Ar retry
4301 If no arguments are given, CBCP (Microsoft's CallBack Control Protocol)
4302 is disabled - ie, configuring CBCP in the
4304 command will result in
4306 requesting no callback in the CBCP phase.
4309 attempts to use the given phone
4310 .Ar number Ns No (s).
4315 will insist that the client uses one of these numbers, unless
4317 is used in which case the client is expected to specify the number.
4321 will attempt to use one of the given numbers (whichever it finds to
4322 be agreeable with the peer), or if
4326 will expect the peer to specify the number.
4328 .No off| Ns Ar seconds Ns Op !\&
4332 checks for the existence of carrier depending on the type of device
4333 that has been opened:
4334 .Bl -tag -width XXX -offset XXX
4335 .It Terminal Devices
4336 Carrier is checked one second after the login script is complete.
4339 assumes that this is because the device doesn't support carrier (which
4342 NULL-modem cables), logs the fact and stops checking
4345 As ptys don't support the TIOCMGET ioctl, the tty device will switch all
4346 carrier detection off when it detects that the device is a pty.
4347 .It ISDN (i4b) Devices
4348 Carrier is checked once per second for 6 seconds.
4349 If it's not set after
4350 the sixth second, the connection attempt is considered to have failed and
4351 the device is closed.
4352 Carrier is always required for i4b devices.
4353 .It PPPoE (netgraph) Devices
4354 Carrier is checked once per second for 5 seconds.
4355 If it's not set after
4356 the fifth second, the connection attempt is considered to have failed and
4357 the device is closed.
4358 Carrier is always required for PPPoE devices.
4361 All other device types don't support carrier.
4362 Setting a carrier value will
4363 result in a warning when the device is opened.
4365 Some modems take more than one second after connecting to assert the carrier
4367 If this delay isn't increased, this will result in
4369 inability to detect when the link is dropped, as
4371 assumes that the device isn't asserting carrier.
4375 command overrides the default carrier behaviour.
4377 specifies the maximum number of seconds that
4379 should wait after the dial script has finished before deciding if
4380 carrier is available or not.
4386 will not check for carrier on the device, otherwise
4388 will not proceed to the login script until either carrier is detected
4391 has elapsed, at which point
4393 assumes that the device will not set carrier.
4395 If no arguments are given, carrier settings will go back to their default
4400 is followed immediately by an exclamation mark
4406 If carrier is not detected after
4408 seconds, the link will be disconnected.
4409 .It set choked Op Ar timeout
4410 This sets the number of seconds that
4412 will keep a choked output queue before dropping all pending output packets.
4415 is less than or equal to zero or if
4417 isn't specified, it is set to the default value of
4420 A choked output queue occurs when
4422 has read a certain number of packets from the local network for transmission,
4423 but cannot send the data due to link failure (the peer is busy etc.).
4425 will not read packets indefinitely.
4426 Instead, it reads up to
4432 packets in multi-link mode), then stops reading the network interface
4435 seconds have passed or at least one packet has been sent.
4439 seconds pass, all pending output packets are dropped.
4440 .It set ctsrts|crtscts on|off
4441 This sets hardware flow control.
4442 Hardware flow control is
4445 .It set deflate Ar out-winsize Op Ar in-winsize
4446 This sets the DEFLATE algorithms default outgoing and incoming window
4452 must be values between
4460 will insist that this window size is used and will not accept any other
4461 values from the peer.
4462 .It set dns Op Ar primary Op Ar secondary
4463 This command specifies DNS overrides for the
4468 command description above for details.
4469 This command does not affect the IP numbers requested using
4471 .It set device|line Xo
4474 This sets the device(s) to which
4476 will talk to the given
4479 All ISDN and serial device names are expected to begin with
4481 ISDN devices are usually called
4483 and serial devices are usually called
4490 it must either begin with an exclamation mark
4493 .No PPPoE: Ns Ar iface Ns Xo
4494 .Op \&: Ns Ar provider Ns
4498 enabled systems), or be of the format
4500 .Ar host : port Op /tcp|udp .
4503 If it begins with an exclamation mark, the rest of the device name is
4504 treated as a program name, and that program is executed when the device
4506 Standard input, output and error are fed back to
4508 and are read and written as if they were a regular device.
4511 .No PPPoE: Ns Ar iface Ns Xo
4512 .Op \&: Ns Ar provider Ns
4514 specification is given,
4516 will attempt to create a
4518 over Ethernet connection using the given
4526 will attempt to load it using
4528 If this fails, an external program must be used such as the
4530 program available under
4534 is passed as the service name in the PPPoE Discovery Initiation (PADI)
4536 If no provider is given, an empty value will be used.
4538 When a PPPoE connection is established,
4540 will place the name of the Access Concentrator in the environment variable
4547 for further details.
4550 .Ar host Ns No : Ns Ar port Ns Oo
4553 specification is given,
4555 will attempt to connect to the given
4563 suffix is not provided, the default is
4565 Refer to the section on
4566 .Em PPP OVER TCP and UDP
4567 above for further details.
4573 will attempt to open each one in turn until it succeeds or runs out of
4575 .It set dial Ar chat-script
4576 This specifies the chat script that will be used to dial the other
4583 and to the example configuration files for details of the chat script
4585 It is possible to specify some special
4587 in your chat script as follows:
4590 When used as the last character in a
4592 string, this indicates that a newline should not be appended.
4594 When the chat script encounters this sequence, it delays two seconds.
4596 When the chat script encounters this sequence, it delays for one quarter of
4599 This is replaced with a newline character.
4601 This is replaced with a carriage return character.
4603 This is replaced with a space character.
4605 This is replaced with a tab character.
4607 This is replaced by the current phone number (see
4611 This is replaced by the current
4617 This is replaced by the current
4624 Note that two parsers will examine these escape sequences, so in order to
4627 see the escape character, it is necessary to escape it from the
4628 .Sq command parser .
4629 This means that in practice you should use two escapes, for example:
4630 .Bd -literal -offset indent
4631 set dial "... ATDT\\\\T CONNECT"
4634 It is also possible to execute external commands from the chat script.
4635 To do this, the first character of the expect or send string is an
4638 If a literal exclamation mark is required, double it up to
4640 and it will be treated as a single literal
4642 When the command is executed, standard input and standard output are
4643 directed to the open device (see the
4645 command), and standard error is read by
4647 and substituted as the expect or send string.
4650 is running in interactive mode, file descriptor 3 is attached to
4653 For example (wrapped for readability):
4654 .Bd -literal -offset indent
4655 set login "TIMEOUT 5 \\"\\" \\"\\" login:--login: ppp \e
4656 word: ppp \\"!sh \\\\-c \\\\\\"echo \\\\-n label: >&2\\\\\\"\\" \e
4657 \\"!/bin/echo in\\" HELLO"
4660 would result in the following chat sequence (output using the
4661 .Sq set log local chat
4662 command before dialing):
4663 .Bd -literal -offset indent
4668 Chat: Expecting: login:--login:
4669 Chat: Wait for (5): login:
4671 Chat: Expecting: word:
4672 Chat: Wait for (5): word:
4674 Chat: Expecting: !sh \\-c "echo \\-n label: >&2"
4675 Chat: Exec: sh -c "echo -n label: >&2"
4676 Chat: Wait for (5): !sh \\-c "echo \\-n label: >&2" --> label:
4677 Chat: Exec: /bin/echo in
4679 Chat: Expecting: HELLO
4680 Chat: Wait for (5): HELLO
4684 Note (again) the use of the escape character, allowing many levels of
4686 Here, there are four parsers at work.
4687 The first parses the original line, reading it as three arguments.
4688 The second parses the third argument, reading it as 11 arguments.
4689 At this point, it is
4692 signs are escaped, otherwise this parser will see them as constituting
4693 an expect-send-expect sequence.
4696 character is seen, the execution parser reads the first command as three
4699 itself expands the argument after the
4701 As we wish to send the output back to the modem, in the first example
4702 we redirect our output to file descriptor 2 (stderr) so that
4704 itself sends and logs it, and in the second example, we just output to stdout,
4705 which is attached directly to the modem.
4707 This, of course means that it is possible to execute an entirely external
4709 command rather than using the internal one.
4712 for a good alternative.
4714 The external command that is executed is subjected to the same special
4715 word expansions as the
4718 .It set enddisc Op label|IP|MAC|magic|psn value
4719 This command sets our local endpoint discriminator.
4720 If set prior to LCP negotiation, and if no
4722 command has been used,
4724 will send the information to the peer using the LCP endpoint discriminator
4726 The following discriminators may be set:
4727 .Bl -tag -width indent
4729 The current label is used.
4731 Our local IP number is used.
4732 As LCP is negotiated prior to IPCP, it is
4733 possible that the IPCP layer will subsequently change this value.
4735 it does, the endpoint discriminator stays at the old value unless manually
4738 This is similar to the
4740 option above, except that the MAC address associated with the local IP
4742 If the local IP number is not resident on any Ethernet
4743 interface, the command will fail.
4745 As the local IP number defaults to whatever the machine host name is,
4747 is usually done prior to any
4751 A 20 digit random number is used.
4752 Care should be taken when using magic numbers as restarting
4754 or creating a link using a different
4756 invocation will also use a different magic number and will therefore not
4757 be recognised by the peer as belonging to the same bundle.
4758 This makes it unsuitable for
4766 should be set to an absolute public switched network number with the
4770 If no arguments are given, the endpoint discriminator is reset.
4771 .It set escape Ar value...
4772 This option is similar to the
4775 It allows the user to specify a set of characters that will be
4777 as they travel across the link.
4778 .It set filter dial|alive|in|out Ar rule-no Xo
4779 .No permit|deny|clear| Ns Ar rule-no
4782 .Ar src_addr Ns Op / Ns Ar width
4783 .Op Ar dst_addr Ns Op / Ns Ar width
4785 .Op src lt|eq|gt Ar port
4786 .Op dst lt|eq|gt Ar port
4790 .Op timeout Ar secs ]
4793 supports four filter sets.
4796 filter specifies packets that keep the connection alive - resetting the
4800 filter specifies packets that cause
4807 filter specifies packets that are allowed to travel
4808 into the machine and the
4810 filter specifies packets that are allowed out of the machine.
4812 Filtering is done prior to any IP alterations that might be done by the
4813 NAT engine on outgoing packets and after any IP alterations that might
4814 be done by the NAT engine on incoming packets.
4815 By default all empty filter sets allow all packets to pass.
4816 Rules are processed in order according to
4818 (unless skipped by specifying a rule number as the
4820 Up to 40 rules may be given for each set.
4821 If a packet doesn't match
4822 any of the rules in a given set, it is discarded.
4827 filters, this means that the packet is dropped.
4830 filters it means that the packet will not reset the idle timer (even if
4832 .Ar in Ns No / Ns Ar out
4835 value) and in the case of
4837 filters it means that the packet will not trigger a dial.
4838 A packet failing to trigger a dial will be dropped rather than queued.
4841 .Sx PACKET FILTERING
4842 above for further details.
4843 .It set hangup Ar chat-script
4844 This specifies the chat script that will be used to reset the device
4845 before it is closed.
4846 It should not normally be necessary, but can
4847 be used for devices that fail to reset themselves properly on close.
4848 .It set help|? Op Ar command
4849 This command gives a summary of available set commands, or if
4851 is specified, the command usage is shown.
4852 .It set ifaddr Oo Ar myaddr Ns
4854 .Oo Ar hisaddr Ns Op / Ns Ar \&nn
4859 This command specifies the IP addresses that will be used during
4861 Addresses are specified using the format
4867 is the preferred IP, but
4869 specifies how many bits of the address we will insist on.
4872 is omitted, it defaults to
4874 unless the IP address is 0.0.0.0 in which case it defaults to
4877 If you wish to assign a dynamic IP number to the peer,
4879 may also be specified as a range of IP numbers in the format
4880 .Bd -ragged -offset indent
4881 .Ar \&IP Ns Oo \&- Ns Ar \&IP Ns Xo
4882 .Oc Ns Oo , Ns Ar \&IP Ns
4883 .Op \&- Ns Ar \&IP Ns
4890 .Dl set ifaddr 10.0.0.1 10.0.1.2-10.0.1.10,10.0.1.20
4894 as the local IP number, but may assign any of the given 10 IP
4895 numbers to the peer.
4896 If the peer requests one of these numbers,
4897 and that number is not already in use,
4899 will grant the peers request.
4900 This is useful if the peer wants
4901 to re-establish a link using the same IP number as was previously
4902 allocated (thus maintaining any existing tcp or udp connections).
4904 If the peer requests an IP number that's either outside
4905 of this range or is already in use,
4907 will suggest a random unused IP number from the range.
4911 is specified, it is used in place of
4913 in the initial IPCP negotiation.
4914 However, only an address in the
4916 range will be accepted.
4917 This is useful when negotiating with some
4919 implementations that will not assign an IP number unless their peer
4923 It should be noted that in
4927 will configure the interface immediately upon reading the
4929 line in the config file.
4930 In any other mode, these values are just
4931 used for IPCP negotiations, and the interface isn't configured
4932 until the IPCP layer is up.
4936 argument may be overridden by the third field in the
4938 file once the client has authenticated itself
4942 .Sx AUTHENTICATING INCOMING CONNECTIONS
4943 section for details.
4945 In all cases, if the interface is already configured,
4947 will try to maintain the interface IP numbers so that any existing
4948 bound sockets will remain valid.
4949 .It set ifqueue Ar packets
4950 Set the maximum number of packets that
4952 will read from the tunnel interface while data cannot be sent to any of
4953 the available links.
4954 This queue limit is necessary to flow control outgoing data as the tunnel
4955 interface is likely to be far faster than the combined links available to
4960 is set to a value less than the number of links,
4962 will read up to that value regardless.
4963 This prevents any possible latency problems.
4965 The default value for
4969 .It set ccpretry|ccpretries Oo Ar timeout
4970 .Op Ar reqtries Op Ar trmtries
4972 .It set chapretry|chapretries Oo Ar timeout
4975 .It set ipcpretry|ipcpretries Oo Ar timeout
4976 .Op Ar reqtries Op Ar trmtries
4978 .It set ipv6cpretry|ipv6cpretries Oo Ar timeout
4979 .Op Ar reqtries Op Ar trmtries
4981 .It set lcpretry|lcpretries Oo Ar timeout
4982 .Op Ar reqtries Op Ar trmtries
4984 .It set papretry|papretries Oo Ar timeout
4987 These commands set the number of seconds that
4989 will wait before resending Finite State Machine (FSM) Request packets.
4992 for all FSMs is 3 seconds (which should suffice in most cases).
4996 is specified, it tells
4998 how many configuration request attempts it should make while receiving
4999 no reply from the peer before giving up.
5000 The default is 5 attempts for
5001 CCP, LCP and IPCP and 3 attempts for PAP and CHAP.
5005 is specified, it tells
5007 how many terminate requests should be sent before giving up waiting for the
5009 The default is 3 attempts.
5010 Authentication protocols are
5011 not terminated and it is therefore invalid to specify
5015 In order to avoid negotiations with the peer that will never converge,
5017 will only send at most 3 times the configured number of
5019 in any given negotiation session before giving up and closing that layer.
5025 This command allows the adjustment of the current log level.
5026 Refer to the Logging Facility section for further details.
5027 .It set login Ar chat-script
5030 compliments the dial-script.
5031 If both are specified, the login
5032 script will be executed after the dial script.
5033 Escape sequences available in the dial script are also available here.
5034 .It set logout Ar chat-script
5035 This specifies the chat script that will be used to logout
5036 before the hangup script is called.
5037 It should not normally be necessary.
5038 .It set lqrperiod Ar frequency
5039 This command sets the
5046 The default is 30 seconds.
5047 You must also use the
5049 command if you wish to send LQR requests to the peer.
5050 .It set mode Ar interactive|auto|ddial|background
5051 This command allows you to change the
5053 of the specified link.
5054 This is normally only useful in multi-link mode,
5055 but may also be used in uni-link mode.
5057 It is not possible to change a link that is
5062 Note: If you issue the command
5064 and have network address translation enabled, it may be useful to
5065 .Dq enable iface-alias
5069 to do the necessary address translations to enable the process that
5070 triggers the connection to connect once the link is up despite the
5071 peer assigning us a new (dynamic) IP address.
5072 .It set mppe Op 40|56|128|* Op stateless|stateful|*
5073 This option selects the encryption parameters used when negotiation
5075 MPPE can be disabled entirely with the
5078 If no arguments are given,
5080 will attempt to negotiate a stateful link with a 128 bit key, but
5081 will agree to whatever the peer requests (including no encryption
5084 If any arguments are given,
5088 on using MPPE and will close the link if it's rejected by the peer (Note;
5089 this behaviour can be overridden by a configured RADIUS server).
5091 The first argument specifies the number of bits that
5093 should insist on during negotiations and the second specifies whether
5095 should insist on stateful or stateless mode.
5096 In stateless mode, the
5097 encryption dictionary is re-initialised with every packet according to
5098 an encryption key that is changed with every packet.
5100 the encryption dictionary is re-initialised every 256 packets or after
5101 the loss of any data and the key is changed every 256 packets.
5102 Stateless mode is less efficient but is better for unreliable transport
5104 .It set mrru Op Ar value
5105 Setting this option enables Multi-link PPP negotiations, also known as
5106 Multi-link Protocol or MP.
5107 There is no default MRRU (Maximum Reconstructed Receive Unit) value.
5108 If no argument is given, multi-link mode is disabled.
5113 The default MRU (Maximum Receive Unit) is 1500.
5114 If it is increased, the other side *may* increase its MTU.
5115 In theory there is no point in decreasing the MRU to below the default as the
5117 protocol says implementations *must* be able to accept packets of at
5124 will refuse to negotiate a higher value.
5125 The maximum MRU can be set to 2048 at most.
5126 Setting a maximum of less than 1500 violates the
5128 rfc, but may sometimes be necessary.
5131 imposes a maximum of 1492 due to hardware limitations.
5133 If no argument is given, 1500 is assumed.
5134 A value must be given when
5141 The default MTU is 1500.
5142 At negotiation time,
5144 will accept whatever MRU the peer requests (assuming it's
5145 not less than 296 bytes or greater than the assigned maximum).
5148 will not accept MRU values less than
5150 When negotiations are complete, the MTU is used when writing to the
5151 interface, even if the peer requested a higher value MRU.
5152 This can be useful for
5153 limiting your packet size (giving better bandwidth sharing at the expense
5154 of more header data).
5160 will refuse to negotiate a higher value.
5161 The maximum MTU can be set to 2048 at most.
5165 is given, 1500, or whatever the peer asks for is used.
5166 A value must be given when
5169 .It set nbns Op Ar x.x.x.x Op Ar y.y.y.y
5170 This option allows the setting of the Microsoft NetBIOS name server
5171 values to be returned at the peers request.
5172 If no values are given,
5174 will reject any such requests.
5175 .It set openmode active|passive Op Ar delay
5184 will always initiate LCP/IPCP/CCP negotiation one second after the line
5186 If you want to wait for the peer to initiate negotiations, you
5189 If you want to initiate negotiations immediately or after more than one
5190 second, the appropriate
5192 may be specified here in seconds.
5193 .It set parity odd|even|none|mark
5194 This allows the line parity to be set.
5195 The default value is
5197 .It set phone Ar telno Ns Xo
5198 .Oo \&| Ns Ar backupnumber
5199 .Oc Ns ... Ns Oo : Ns Ar nextnumber
5202 This allows the specification of the phone number to be used in
5203 place of the \\\\T string in the dial and login chat scripts.
5204 Multiple phone numbers may be given separated either by a pipe
5209 Numbers after the pipe are only dialed if the dial or login
5210 script for the previous number failed.
5212 Numbers after the colon are tried sequentially, irrespective of
5213 the reason the line was dropped.
5215 If multiple numbers are given,
5217 will dial them according to these rules until a connection is made, retrying
5218 the maximum number of times specified by
5223 mode, each number is attempted at most once.
5224 .It set Op proc Ns Xo
5225 .No title Op Ar value
5227 The current process title as displayed by
5229 is changed according to
5233 is not specified, the original process title is restored.
5235 word replacements done by the shell commands (see the
5237 command above) are done here too.
5239 Note, if USER is required in the process title, the
5241 command must appear in
5243 as it is not known when the commands in
5246 .It set radius Op Ar config-file
5247 This command enables RADIUS support (if it's compiled in).
5249 refers to the radius client configuration file as described in
5251 If PAP, CHAP, MSCHAP or MSCHAPv2 are
5252 .Dq enable Ns No d ,
5255 .Em \&N Ns No etwork
5258 and uses the configured RADIUS server to authenticate rather than
5259 authenticating from the
5261 file or from the passwd database.
5263 If none of PAP, CHAP, MSCHAP or MSCHAPv2 are enabled,
5268 uses the following attributes from the RADIUS reply:
5269 .Bl -tag -width XXX -offset XXX
5270 .It RAD_FRAMED_IP_ADDRESS
5271 The peer IP address is set to the given value.
5272 .It RAD_FRAMED_IP_NETMASK
5273 The tun interface netmask is set to the given value.
5275 If the given MTU is less than the peers MRU as agreed during LCP
5276 negotiation, *and* it is less that any configured MTU (see the
5278 command), the tun interface MTU is set to the given value.
5279 .It RAD_FRAMED_COMPRESSION
5280 If the received compression type is
5283 will request VJ compression during IPCP negotiations despite any
5285 configuration command.
5287 If this attribute is supplied,
5289 will attempt to use it as an additional label to load from the
5294 The load will be attempted before (and in addition to) the normal
5296 If the label doesn't exist, no action is taken and
5298 proceeds to the normal load using the current label.
5299 .It RAD_FRAMED_ROUTE
5300 The received string is expected to be in the format
5301 .Ar dest Ns Op / Ns Ar bits
5304 Any specified metrics are ignored.
5308 are understood as valid values for
5315 to sepcify the default route, and
5317 is understood to be the same as
5326 For example, a returned value of
5327 .Dq 1.2.3.4/24 0.0.0.0 1 2 -1 3 400
5328 would result in a routing table entry to the 1.2.3.0/24 network via
5330 and a returned value of
5334 would result in a default route to
5337 All RADIUS routes are applied after any sticky routes are applied, making
5338 RADIUS routes override configured routes.
5339 This also applies for RADIUS routes that don't {include} the
5345 .It RAD_SESSION_TIMEOUT
5346 If supplied, the client connection is closed after the given number of
5348 .It RAD_REPLY_MESSAGE
5349 If supplied, this message is passed back to the peer as the authentication
5351 .It RAD_MICROSOFT_MS_CHAP_ERROR
5353 .Dv RAD_VENDOR_MICROSOFT
5354 vendor specific attribute is supplied, it is passed back to the peer as the
5355 authentication FAILURE text.
5356 .It RAD_MICROSOFT_MS_CHAP2_SUCCESS
5358 .Dv RAD_VENDOR_MICROSOFT
5359 vendor specific attribute is supplied and if MS-CHAPv2 authentication is
5360 being used, it is passed back to the peer as the authentication SUCCESS text.
5361 .It RAD_MICROSOFT_MS_MPPE_ENCRYPTION_POLICY
5363 .Dv RAD_VENDOR_MICROSOFT
5364 vendor specific attribute is supplied and has a value of 2 (Required),
5366 will insist that MPPE encryption is used (even if no
5368 configuration command has been given with arguments).
5369 If it is supplied with a value of 1 (Allowed), encryption is made optional
5372 configuration commands with arguments).
5373 .It RAD_MICROSOFT_MS_MPPE_ENCRYPTION_TYPES
5375 .Dv RAD_VENDOR_MICROSOFT
5376 vendor specific attribute is supplied, bits 1 and 2 are examined.
5377 If either or both are set, 40 bit and/or 128 bit (respectively) encryption
5378 options are set, overriding any given first argument to the
5381 Note, it is not currently possible for the RADIUS server to specify 56 bit
5383 .It RAD_MICROSOFT_MS_MPPE_RECV_KEY
5385 .Dv RAD_VENDOR_MICROSOFT
5386 vendor specific attribute is supplied, it's value is used as the master
5387 key for decryption of incoming data. When clients are authenticated using
5388 MSCHAPv2, the RADIUS server MUST provide this attribute if inbound MPPE is
5390 .It RAD_MICROSOFT_MS_MPPE_SEND_KEY
5392 .Dv RAD_VENDOR_MICROSOFT
5393 vendor specific attribute is supplied, it's value is used as the master
5394 key for encryption of outgoing data. When clients are authenticated using
5395 MSCHAPv2, the RADIUS server MUST provide this attribute if outbound MPPE is
5399 Values received from the RADIUS server may be viewed using
5401 .It set reconnect Ar timeout ntries
5402 Should the line drop unexpectedly (due to loss of CD or LQR
5403 failure), a connection will be re-established after the given
5405 The line will be re-connected at most
5414 will result in a variable pause, somewhere between 1 and 30 seconds.
5415 .It set recvpipe Op Ar value
5416 This sets the routing table RECVPIPE value.
5417 The optimum value is just over twice the MTU value.
5420 is unspecified or zero, the default kernel controlled value is used.
5421 .It set redial Ar secs Ns Xo
5424 .Oc Ns Op . Ns Ar next
5428 can be instructed to attempt to redial
5431 If more than one phone number is specified (see
5435 is taken before dialing each number.
5438 is taken before starting at the first number again.
5441 may be used here in place of
5445 causing a random delay of between 1 and 30 seconds.
5449 is specified, its value is added onto
5455 will only be incremented at most
5463 delay will be effective, even after
5465 has been exceeded, so an immediate manual dial may appear to have
5467 If an immediate dial is required, a
5469 should immediately follow the
5474 description above for further details.
5475 .It set sendpipe Op Ar value
5476 This sets the routing table SENDPIPE value.
5477 The optimum value is just over twice the MTU value.
5480 is unspecified or zero, the default kernel controlled value is used.
5481 .It "set server|socket" Ar TcpPort Ns No \&| Ns Xo
5482 .Ar LocalName Ns No |none|open|closed
5483 .Op password Op Ar mask
5487 to listen on the given socket or
5489 for incoming command connections.
5495 to close any existing socket and clear the socket configuration.
5500 to attempt to re-open the port.
5505 to close the open port.
5507 If you wish to specify a local domain socket,
5509 must be specified as an absolute file name, otherwise it is assumed
5510 to be the name or number of a TCP port.
5511 You may specify the octal umask to be used with a local domain socket.
5517 for details of how to translate TCP port names.
5519 You must also specify the password that must be entered by the client
5522 variable above) when connecting to this socket.
5524 specified as an empty string, no password is required for connecting clients.
5526 When specifying a local domain socket, the first
5528 sequence found in the socket name will be replaced with the current
5529 interface unit number.
5530 This is useful when you wish to use the same
5531 profile for more than one connection.
5533 In a similar manner TCP sockets may be prefixed with the
5535 character, in which case the current interface unit number is added to
5540 with a server socket, the
5542 command is the preferred mechanism of communications.
5545 can also be used, but link encryption may be implemented in the future, so
5553 interact with the diagnostic socket.
5554 .It set speed Ar value
5555 This sets the speed of the serial device.
5556 If speed is specified as
5559 treats the device as a synchronous device.
5561 Certain device types will know whether they should be specified as
5562 synchronous or asynchronous.
5563 These devices will override incorrect
5564 settings and log a warning to this effect.
5565 .It set stopped Op Ar LCPseconds Op Ar CCPseconds
5566 If this option is set,
5568 will time out after the given FSM (Finite State Machine) has been in
5569 the stopped state for the given number of
5571 This option may be useful if the peer sends a terminate request,
5572 but never actually closes the connection despite our sending a terminate
5574 This is also useful if you wish to
5575 .Dq set openmode passive
5576 and time out if the peer doesn't send a Configure Request within the
5579 .Dq set log +lcp +ccp
5582 log the appropriate state transitions.
5584 The default value is zero, where
5586 doesn't time out in the stopped state.
5588 This value should not be set to less than the openmode delay (see
5591 .It set timeout Ar idleseconds Op Ar mintimeout
5592 This command allows the setting of the idle timer.
5593 Refer to the section titled
5594 .Sx SETTING THE IDLE TIMER
5595 for further details.
5601 will never idle out before the link has been up for at least that number
5609 This command controls the ports that
5611 prioritizes when transmitting data.
5612 The default priority TCP ports
5613 are ports 21 (ftp control), 22 (ssh), 23 (telnet), 513 (login), 514 (shell),
5614 543 (klogin) and 544 (kshell).
5615 There are no priority UDP ports by default.
5630 are given, the priority port lists are cleared (although if
5634 is specified, only that list is cleared).
5637 argument is prefixed with a plus
5641 the current list is adjusted, otherwise the list is reassigned.
5643 prefixed with a plus or not prefixed at all are added to the list and
5645 prefixed with a minus are removed from the list.
5649 is specified, all priority port lists are disabled and even
5651 packets are not prioritised.
5652 .It set vj slotcomp on|off
5655 whether it should attempt to negotiate VJ slot compression.
5656 By default, slot compression is turned
5658 .It set vj slots Ar nslots
5659 This command sets the initial number of slots that
5661 will try to negotiate with the peer when VJ compression is enabled (see the
5664 It defaults to a value of 16.
5673 .It shell|! Op Ar command
5676 is not specified a shell is invoked according to the
5678 environment variable.
5679 Otherwise, the given
5682 Word replacement is done in the same way as for the
5684 command as described above.
5686 Use of the ! character
5687 requires a following space as with any of the other commands.
5688 You should note that this command is executed in the foreground;
5690 will not continue running until this process has exited.
5693 command if you wish processing to happen in the background.
5695 This command allows the user to examine the following:
5698 Show the current bundle settings.
5700 Show the current CCP compression statistics.
5702 Show the current VJ compression statistics.
5704 Show the current escape characters.
5705 .It show filter Op Ar name
5706 List the current rules for the given filter.
5709 is not specified, all filters are shown.
5711 Show the current HDLC statistics.
5713 Give a summary of available show commands.
5715 Show the current interface information
5719 Show the current IPCP statistics.
5721 Show the protocol layers currently in use.
5723 Show the current LCP statistics.
5724 .It show Op data Ns Xo
5727 Show high level link information.
5729 Show a list of available logical links.
5731 Show the current log values.
5733 Show current memory statistics.
5735 Show the current NCP statistics.
5737 Show low level link information.
5739 Show Multi-link information.
5741 Show current protocol totals.
5743 Show the current routing tables.
5745 Show the current stopped timeouts.
5747 Show the active alarm timers.
5749 Show the current version number of
5754 Go into terminal mode.
5755 Characters typed at the keyboard are sent to the device.
5756 Characters read from the device are displayed on the screen.
5761 automatically enables Packet Mode and goes back into command mode.
5766 Read the example configuration files.
5767 They are a good source of information.
5776 to get online information about what's available.
5778 The following URLs contain useful information:
5779 .Bl -bullet -compact
5781 http://www.FreeBSD.org/doc/en_US.ISO8859-1/books/faq/ppp.html
5783 http://www.FreeBSD.org/doc/handbook/userppp.html
5788 refers to four files:
5794 These files are placed in the
5798 .It Pa /etc/ppp/ppp.conf
5799 System default configuration file.
5800 .It Pa /etc/ppp/ppp.secret
5801 An authorisation file for each system.
5802 .It Pa /etc/ppp/ppp.linkup
5803 A file to check when
5805 establishes a network level connection.
5806 .It Pa /etc/ppp/ppp.linkdown
5807 A file to check when
5809 closes a network level connection.
5810 .It Pa /var/log/ppp.log
5811 Logging and debugging information file.
5812 Note, this name is specified in
5813 .Pa /etc/syslog.conf .
5816 for further details.
5817 .It Pa /var/spool/lock/LCK..*
5818 tty port locking file.
5821 for further details.
5822 .It Pa /var/run/tunN.pid
5823 The process id (pid) of the
5825 program connected to the tunN device, where
5827 is the number of the device.
5828 .It Pa /var/run/ttyXX.if
5829 The tun interface used by this port.
5830 Again, this file is only created in
5836 .It Pa /etc/services
5837 Get port number if port number is using service name.
5838 .It Pa /var/run/ppp-authname-class-value
5839 In multi-link mode, local domain sockets are created using the peer
5842 the peer endpoint discriminator class
5844 and the peer endpoint discriminator value
5846 As the endpoint discriminator value may be a binary value, it is turned
5847 to HEX to determine the actual file name.
5849 This socket is used to pass links between different instances of
5861 ifdef({LOCALNAT},{},{.Xr libalias 3 ,
5863 ifdef({LOCALRAD},{},{.Xr libradius 3 ,
5893 This program was originally written by
5894 .An Toshiharu OHNO Aq tony-o@iij.ad.jp ,
5895 and was submitted to
5898 .An Atsushi Murai Aq amurai@spec.co.jp .
5900 It was substantially modified during 1997 by
5901 .An Brian Somers Aq brian@Awfulhak.org ,
5904 in November that year
5905 (just after the 2.2 release).
5907 Most of the code was rewritten by
5909 in early 1998 when multi-link ppp support was added.
projects / dragonfly.git / blob