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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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
18 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 $
35 .Nd Point to Point Protocol (a.k.a. user-ppp)
44 This is a user process
49 is implemented as a part of the kernel (e.g., as managed by
51 and it's thus somewhat hard to debug and/or modify its behaviour.
52 However, in this implementation
54 is done as a user process with the help of the
55 tunnel device driver (tun).
59 flag does the equivalent of a
63 network address translation features.
66 to act as a NAT or masquerading engine for all machines on an internal
68 ifdef({LOCALNAT},{},{Refer to
70 for details on the technical side of the NAT engine.
73 .Sx NETWORK ADDRESS TRANSLATION (PACKET ALIASING)
74 section of this manual page for details on how to configure NAT in
81 to be silent at startup rather than displaying the mode and interface
88 to only attempt to open
89 .Pa /dev/tun Ns Ar N .
92 will start with a value of 0 for
94 and keep trying to open a tunnel device by incrementing the value of
96 by one each time until it succeeds.
97 If it fails three times in a row
98 because the device file is missing, it gives up.
104 .Bl -tag -width XXX -offset XXX
107 opens the tun interface, configures it then goes into the background.
108 The link isn't brought up until outgoing data is detected on the tun
109 interface at which point
111 attempts to bring up the link.
112 Packets received (including the first one) while
114 is trying to bring the link up will remain queued for a default of
124 must be given on the command line (see below) and a
126 must be done in the system profile that specifies a peer IP address to
127 use when configuring the interface.
130 is usually appropriate.
134 .Pa /usr/share/examples/ppp/ppp.conf.sample
139 attempts to establish a connection with the peer immediately.
142 goes into the background and the parent process returns an exit code
146 exits with a non-zero result.
150 attempts to establish a connection with the peer immediately, but never
152 The link is created in background mode.
153 This is useful if you wish to control
155 invocation from another process.
157 This is used for receiving incoming connections.
161 line and uses descriptor 0 as the link.
163 If callback is configured,
167 information when dialing back.
169 This option is designed for machines connected with a dedicated
172 will always keep the device open and will never use any configured
175 This mode is equivalent to
179 will bring the link back up any time it's dropped for any reason.
181 This is a no-op, and gives the same behaviour as if none of the above
182 modes have been specified.
184 loads any sections specified on the command line then provides an
188 One or more configuration entries or systems
190 .Pa /etc/ppp/ppp.conf )
191 may also be specified on the command line.
196 .Pa /etc/ppp/ppp.conf
197 at startup, followed by each of the systems specified on the command line.
200 .It Provides an interactive user interface.
201 Using its command mode, the user can
202 easily enter commands to establish the connection with the remote end, check
203 the status of connection and close the connection.
204 All functions can also be optionally password protected for security.
205 .It Supports both manual and automatic dialing.
206 Interactive mode has a
208 command which enables you to talk to the device directly.
209 When you are connected to the remote peer and it starts to talk
212 detects it and switches to packet mode automatically.
214 determined the proper sequence for connecting with the remote host, you
215 can write a chat script to {define} the necessary dialing and login
216 procedure for later convenience.
217 .It Supports on-demand dialup capability.
222 will act as a daemon and wait for a packet to be sent over the
225 When this happens, the daemon automatically dials and establishes the
227 In almost the same manner
229 mode (direct-dial mode) also automatically dials and establishes the
231 However, it differs in that it will dial the remote site
232 any time it detects the link is down, even if there are no packets to be
234 This mode is useful for full-time connections where we worry less
235 about line charges and more about being connected full time.
238 mode is also available.
239 This mode is targeted at a dedicated link between two machines.
241 will never voluntarily quit from dedicated mode - you must send it the
243 command via its diagnostic socket.
246 will force an LCP renegotiation, and a
248 will force it to exit.
249 .It Supports client callback.
251 can use either the standard LCP callback protocol or the Microsoft
252 CallBack Control Protocol
253 .Pa ( 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 Ethernet (rfc 2516).
343 is given a device specification of the format
344 .No PPPoE: Ns Ar iface Ns Xo
345 .Op \&: Ns Ar provider Ns
359 On systems that do not support
361 an external program such as
364 .It "Supports IETF draft Predictor-1 (rfc 1978) and DEFLATE (rfc 1979) compression."
366 supports not only VJ-compression but also Predictor-1 and DEFLATE compression.
367 Normally, a modem has built-in compression (e.g., v42.bis) and the system
368 may receive higher data rates from it as a result of such compression.
369 While this is generally a good thing in most other situations, this
370 higher speed data imposes a penalty on the system by increasing the
371 number of serial interrupts the system has to process in talking to the
372 modem and also increases latency.
373 Unlike VJ-compression, Predictor-1 and DEFLATE compression pre-compresses
375 network traffic flowing through the link, thus reducing overheads to a
377 .It Supports Microsoft's IPCP extensions (rfc 1877).
378 Name Server Addresses and NetBIOS Name Server Addresses can be negotiated
379 with clients using the Microsoft
381 stack (i.e., Win95, WinNT)
382 .It Supports Multi-link PPP (rfc 1990)
383 It is possible to configure
385 to open more than one physical connection to the peer, combining the
386 bandwidth of all links for better throughput.
387 .It Supports MPPE (draft-ietf-pppext-mppe)
388 MPPE is Microsoft Point to Point Encryption scheme.
389 It is possible to configure
391 to participate in Microsoft's Windows VPN.
394 can only get encryption keys from CHAP 81 authentication.
396 must be compiled with DES for MPPE to operate.
397 .It Supports IPV6CP (rfc 2023).
398 An IPv6 connection can be made in addition to or instead of the normal
411 will not run if the invoking user id is not zero.
412 This may be overridden by using the
415 .Pa /etc/ppp/ppp.conf .
416 When running as a normal user,
418 switches to user id 0 in order to alter the system routing table, set up
419 system lock files and read the ppp configuration files.
420 All external commands (executed via the "shell" or "!bg" commands) are executed
421 as the user id that invoked
425 logging facility if you're interested in what exactly is done as user id
430 you may need to deal with some initial configuration details.
433 Your kernel must {include} a tunnel device (the X86_64_GENERIC kernel includes
435 If it doesn't, or if you require more than one tun
436 interface, you'll need to rebuild your kernel with the following line in
437 your kernel configuration file:
439 .Dl pseudo-device tun N
443 is the maximum number of
445 connections you wish to support.
447 Make sure that your system has a group named
451 file and that the group contains the names of all users expected to use
455 manual page for details.
456 Each of these users must also be given access using the
459 .Pa /etc/ppp/ppp.conf .
466 A common log file name is
467 .Pa /var/log/ppp.log .
468 To make output go to this file, put the following lines in the
471 .Bd -literal -offset indent
473 *.*<TAB>/var/log/ppp.log
476 It is possible to have more than one
478 log file by creating a link to the
486 .Bd -literal -offset indent
488 *.*<TAB>/var/log/ppp0.log
492 .Pa /etc/syslog.conf .
493 Don't forget to send a
498 .Pa /etc/syslog.conf .
500 Although not strictly relevant to
502 operation, you should configure your resolver so that it works correctly.
503 This can be done by configuring a local DNS
506 or by adding the correct
509 .Pa /etc/resolv.conf .
512 manual page for details.
514 Alternatively, if the peer supports it,
516 can be configured to ask the peer for the nameserver address(es) and to
524 commands below for details.
527 In the following examples, we assume that your machine name is
533 above) with no arguments, you are presented with a prompt:
534 .Bd -literal -offset indent
540 part of your prompt should always be in upper case.
541 If it is in lower case, it means that you must supply a password using the
544 This only ever happens if you connect to a running version of
546 and have not authenticated yourself using the correct password.
548 You can start by specifying the device name and speed:
549 .Bd -literal -offset indent
550 ppp ON awfulhak> set device /dev/cuaa0
551 ppp ON awfulhak> set speed 38400
554 Normally, hardware flow control (CTS/RTS) is used.
556 certain circumstances (as may happen when you are connected directly
557 to certain PPP-capable terminal servers), this may result in
559 hanging as soon as it tries to write data to your communications link
560 as it is waiting for the CTS (clear to send) signal - which will never
562 Thus, if you have a direct line and can't seem to make a
563 connection, try turning CTS/RTS off with
565 If you need to do this, check the
567 description below too - you'll probably need to
568 .Dq set accmap 000a0000 .
570 Usually, parity is set to
575 Parity is a rather archaic error checking mechanism that is no
576 longer used because modern modems do their own error checking, and most
577 link-layer protocols (that's what
579 is) use much more reliable checking mechanisms.
580 Parity has a relatively
581 huge overhead (a 12.5% increase in traffic) and as a result, it is always
588 However, some ISPs (Internet Service Providers) may use
589 specific parity settings at connection time (before
592 Notably, Compuserve insist on even parity when logging in:
593 .Bd -literal -offset indent
594 ppp ON awfulhak> set parity even
597 You can now see what your current device settings look like:
598 .Bd -literal -offset indent
599 ppp ON awfulhak> show physical
603 Link Type: interactive
609 Device List: /dev/cuaa0
610 Characteristics: 38400bps, cs8, even parity, CTS/RTS on
613 0 octets in, 0 octets out
618 The term command can now be used to talk directly to the device:
619 .Bd -literal -offset indent
620 ppp ON awfulhak> term
626 Password: myisppassword
630 When the peer starts to talk in
633 detects this automatically and returns to command mode.
634 .Bd -literal -offset indent
635 ppp ON awfulhak> # No link has been established
636 Ppp ON awfulhak> # We've connected & finished LCP
637 PPp ON awfulhak> # We've authenticated
638 PPP ON awfulhak> # We've agreed IP numbers
641 If it does not, it's probable that the peer is waiting for your end to
647 configuration packets to the peer, use the
649 command to drop out of terminal mode and enter packet mode.
651 If you never even receive a login prompt, it is quite likely that the
652 peer wants to use PAP or CHAP authentication instead of using Unix-style
653 login/password authentication.
654 To set things up properly, drop back to
655 the prompt and set your authentication name and key, then reconnect:
656 .Bd -literal -offset indent
658 ppp ON awfulhak> set authname myispusername
659 ppp ON awfulhak> set authkey myisppassword
660 ppp ON awfulhak> term
667 You may need to tell ppp to initiate negotiations with the peer here too:
668 .Bd -literal -offset indent
670 ppp ON awfulhak> # No link has been established
671 Ppp ON awfulhak> # We've connected & finished LCP
672 PPp ON awfulhak> # We've authenticated
673 PPP ON awfulhak> # We've agreed IP numbers
676 You are now connected!
679 in the prompt has changed to capital letters to indicate that you have
681 If only some of the three Ps go uppercase, wait until
682 either everything is uppercase or lowercase.
683 If they revert to lowercase, it means that
685 couldn't successfully negotiate with the peer.
686 A good first step for troubleshooting at this point would be to
687 .Bd -literal -offset indent
688 ppp ON awfulhak> set log local phase lcp ipcp
694 command description below for further details.
695 If things fail at this point,
696 it is quite important that you turn logging on and try again.
698 important that you note any prompt changes and report them to anyone trying
701 When the link is established, the show command can be used to see how
703 .Bd -literal -offset indent
704 PPP ON awfulhak> show physical
705 * Modem related information is shown here *
706 PPP ON awfulhak> show ccp
707 * CCP (compression) related information is shown here *
708 PPP ON awfulhak> show lcp
709 * LCP (line control) related information is shown here *
710 PPP ON awfulhak> show ipcp
711 * IPCP (IP) related information is shown here *
712 PPP ON awfulhak> show ipv6cp
713 * IPV6CP (IPv6) related information is shown here *
714 PPP ON awfulhak> show link
715 * Link (high level) related information is shown here *
716 PPP ON awfulhak> show bundle
717 * Logical (high level) connection related information is shown here *
720 At this point, your machine has a host route to the peer.
722 that you can only make a connection with the host on the other side
724 If you want to add a default route entry (telling your
725 machine to send all packets without another routing entry to the other
728 link), enter the following command:
729 .Bd -literal -offset indent
730 PPP ON awfulhak> add default HISADDR
735 represents the IP address of the connected peer.
738 command fails due to an existing route, you can overwrite the existing
740 .Bd -literal -offset indent
741 PPP ON awfulhak> add! default HISADDR
744 This command can also be executed before actually making the connection.
745 If a new IP address is negotiated at connection time,
747 will update your default route accordingly.
749 You can now use your network applications (ping, telnet, ftp etc.)
750 in other windows or terminals on your machine.
751 If you wish to reuse the current terminal, you can put
753 into the background using your standard shell suspend and background
761 section for details on all available commands.
762 .Sh AUTOMATIC DIALING
763 To use automatic dialing, you must prepare some Dial and Login chat scripts.
764 See the example definitions in
765 .Pa /usr/share/examples/ppp/ppp.conf.sample
767 .Pa /etc/ppp/ppp.conf
769 Each line contains one comment, inclusion, label or command:
772 A line starting with a
774 character is treated as a comment line.
775 Leading whitespace are ignored when identifying comment lines.
777 An inclusion is a line beginning with the word
779 It must have one argument - the file to {include}.
781 .Dq {!include} ~/.ppp.conf
782 for compatibility with older versions of
785 A label name starts in the first column and is followed by
789 A command line must contain a space or tab in the first column.
793 .Pa /etc/ppp/ppp.conf
794 file should consist of at least a
797 This section is always executed.
798 It should also contain
799 one or more sections, named according to their purpose, for example,
801 would represent your ISP, and
803 would represent an incoming
806 You can now specify the destination label name when you invoke
808 Commands associated with the
810 label are executed, followed by those associated with the destination
814 is started with no arguments, the
816 section is still executed.
817 The load command can be used to manually load a section from the
818 .Pa /etc/ppp/ppp.conf
820 .Bd -literal -offset indent
821 ppp ON awfulhak> load MyISP
824 Note, no action is taken by
826 after a section is loaded, whether it's the result of passing a label on
827 the command line or using the
830 Only the commands specified for that label in the configuration
832 However, when invoking
839 switches, the link mode tells
841 to establish a connection.
844 command below for further details.
846 Once the connection is made, the
848 portion of the prompt will change to
850 .Bd -literal -offset indent
853 ppp ON awfulhak> dial
859 The Ppp prompt indicates that
861 has entered the authentication phase.
862 The PPp prompt indicates that
864 has entered the network phase.
865 The PPP prompt indicates that
867 has successfully negotiated a network layer protocol and is in
871 .Pa /etc/ppp/ppp.linkup
872 file is available, its contents are executed
875 connection is established.
879 .Pa /usr/share/examples/ppp/ppp.conf.sample
880 which runs a script in the background after the connection is established
885 commands below for a description of possible substitution strings).
886 Similarly, when a connection is closed, the contents of the
887 .Pa /etc/ppp/ppp.linkdown
889 Both of these files have the same format as
890 .Pa /etc/ppp/ppp.conf .
892 In previous versions of
894 it was necessary to re-add routes such as the default route in the
900 where all routes that contain the
906 literals will automatically be updated when the values of these variables
908 .Sh BACKGROUND DIALING
909 If you want to establish a connection using
911 non-interactively (such as from a
915 job) you should use the
922 attempts to establish the connection immediately.
924 numbers are specified, each phone number will be tried once.
925 If the attempt fails,
927 exits immediately with a non-zero exit code.
930 becomes a daemon, and returns an exit status of zero to its caller.
931 The daemon exits automatically if the connection is dropped by the
932 remote system, or it receives a
936 Demand dialing is enabled with the
941 You must also specify the destination label in
942 .Pa /etc/ppp/ppp.conf
946 command to {define} the remote peers IP address.
948 .Pa /usr/share/examples/ppp/ppp.conf.sample )
949 .Bd -literal -offset indent
959 runs as a daemon but you can still configure or examine its
960 configuration by using the
963 .Pa /etc/ppp/ppp.conf ,
965 .Dq Li "set server +3000 mypasswd" )
966 and connecting to the diagnostic port as follows:
967 .Bd -literal -offset indent
968 # pppctl 3000 (assuming tun0)
970 PPP ON awfulhak> show who
971 tcp (127.0.0.1:1028) *
976 command lists users that are currently connected to
979 If the diagnostic socket is closed or changed to a different
980 socket, all connections are immediately dropped.
984 mode, when an outgoing packet is detected,
986 will perform the dialing action (chat script) and try to connect
990 mode, the dialing action is performed any time the line is found
992 If the connect fails, the default behaviour is to wait 30 seconds
993 and then attempt to connect when another outgoing packet is detected.
994 This behaviour can be changed using the
998 .No set redial Ar secs Ns Xo
1001 .Oc Ns Op . Ns Ar next
1005 .Bl -tag -width attempts -compact
1007 is the number of seconds to wait before attempting
1009 If the argument is the literal string
1011 the delay period is a random value between 1 and 30 seconds inclusive.
1013 is the number of seconds that
1015 should be incremented each time a new dial attempt is made.
1016 The timeout reverts to
1018 only after a successful connection is established.
1019 The default value for
1023 is the maximum number of times
1027 The default value for
1031 is the number of seconds to wait before attempting
1032 to dial the next number in a list of numbers (see the
1035 The default is 3 seconds.
1036 Again, if the argument is the literal string
1038 the delay period is a random value between 1 and 30 seconds.
1040 is the maximum number of times to try to connect for each outgoing packet
1041 that triggers a dial.
1042 The previous value is unchanged if this parameter is omitted.
1043 If a value of zero is specified for
1046 will keep trying until a connection is made.
1050 .Bd -literal -offset indent
1054 will attempt to connect 4 times for each outgoing packet that causes
1055 a dial attempt with a 3 second delay between each number and a 10 second
1056 delay after all numbers have been tried.
1057 If multiple phone numbers
1058 are specified, the total number of attempts is still 4 (it does not
1059 attempt each number 4 times).
1062 .Bd -literal -offset indent
1063 set redial 10+10-5.3 20
1068 to attempt to connect 20 times.
1069 After the first attempt,
1071 pauses for 10 seconds.
1072 After the next attempt it pauses for 20 seconds
1073 and so on until after the sixth attempt it pauses for 1 minute.
1074 The next 14 pauses will also have a duration of one minute.
1077 connects, disconnects and fails to connect again, the timeout starts again
1080 Modifying the dial delay is very useful when running
1084 mode on both ends of the link.
1085 If each end has the same timeout,
1086 both ends wind up calling each other at the same time if the link
1087 drops and both ends have packets queued.
1088 At some locations, the serial link may not be reliable, and carrier
1089 may be lost at inappropriate times.
1090 It is possible to have
1092 redial should carrier be unexpectedly lost during a session.
1093 .Bd -literal -offset indent
1094 set reconnect timeout ntries
1099 to re-establish the connection
1101 times on loss of carrier with a pause of
1103 seconds before each try.
1105 .Bd -literal -offset indent
1111 that on an unexpected loss of carrier, it should wait
1113 seconds before attempting to reconnect.
1114 This may happen up to
1119 The default value of ntries is zero (no reconnect).
1120 Care should be taken with this option.
1121 If the local timeout is slightly
1122 longer than the remote timeout, the reconnect feature will always be
1123 triggered (up to the given number of times) after the remote side
1124 times out and hangs up.
1125 NOTE: In this context, losing too many LQRs constitutes a loss of
1126 carrier and will trigger a reconnect.
1129 flag is specified, all phone numbers are dialed at most once until
1130 a connection is made.
1131 The next number redial period specified with the
1133 command is honoured, as is the reconnect tries value.
1135 value is less than the number of phone numbers specified, not all
1136 the specified numbers will be tried.
1137 To terminate the program, type
1138 .Bd -literal -offset indent
1139 PPP ON awfulhak> close
1140 ppp ON awfulhak> quit all
1145 command will terminate the
1149 connection but not the
1157 .Sh RECEIVING INCOMING PPP CONNECTIONS (Method 1)
1158 To handle an incoming
1160 connection request, follow these steps:
1163 Make sure the modem and (optionally)
1164 .Pa /etc/rc.d/serial
1165 is configured correctly.
1166 .Bl -bullet -compact
1168 Use Hardware Handshake (CTS/RTS) for flow control.
1170 Modem should be set to NO echo back (ATE0) and NO results string (ATQ1).
1177 on the port where the modem is attached.
1180 .Dl ttyd1 Qo /usr/libexec/getty std.38400 Qc dialup on secure
1182 Don't forget to send a
1186 process to start the
1191 It is usually also necessary to train your modem to the same DTR speed
1193 .Bd -literal -offset indent
1195 ppp ON awfulhak> set device /dev/cuaa1
1196 ppp ON awfulhak> set speed 38400
1197 ppp ON awfulhak> term
1198 deflink: Entering terminal mode on /dev/cuaa1
1209 ppp ON awfulhak> quit
1213 .Pa /usr/local/bin/ppplogin
1214 file with the following contents:
1215 .Bd -literal -offset indent
1217 exec /usr/sbin/ppp -direct incoming
1224 work with stdin and stdout.
1227 to connect to a configured diagnostic port, in the same manner as with
1233 section must be set up in
1234 .Pa /etc/ppp/ppp.conf .
1238 section contains the
1240 command as appropriate.
1242 Prepare an account for the incoming user.
1244 ppp:xxxx:66:66:PPP Login User:/home/ppp:/usr/local/bin/ppplogin
1247 Refer to the manual entries for
1253 Support for IPCP Domain Name Server and NetBIOS Name Server negotiation
1254 can be enabled using the
1259 Refer to their descriptions below.
1261 .Sh RECEIVING INCOMING PPP CONNECTIONS (Method 2)
1262 This method differs in that we use
1264 to authenticate the connection rather than
1268 Configure your default section in
1270 with automatic ppp recognition by specifying the
1275 :pp=/usr/local/bin/ppplogin:\\
1279 Configure your serial device(s), enable a
1282 .Pa /usr/local/bin/ppplogin
1283 as in the first three steps for method 1 above.
1291 .Pa /etc/ppp/ppp.conf
1294 label (or whatever label
1299 .Pa /etc/ppp/ppp.secret
1300 for each incoming user:
1309 detects a ppp connection (by recognising the HDLC frame headers), it runs
1310 .Dq /usr/local/bin/ppplogin .
1314 that either PAP or CHAP are enabled as above.
1315 If they are not, you are
1316 allowing anybody to establish a ppp session with your machine
1318 a password, opening yourself up to all sorts of potential attacks.
1319 .Sh AUTHENTICATING INCOMING CONNECTIONS
1320 Normally, the receiver of a connection requires that the peer
1321 authenticates itself.
1322 This may be done using
1324 but alternatively, you can use PAP or CHAP.
1325 CHAP is the more secure of the two, but some clients may not support it.
1326 Once you decide which you wish to use, add the command
1330 to the relevant section of
1333 You must then configure the
1334 .Pa /etc/ppp/ppp.secret
1336 This file contains one line per possible client, each line
1337 containing up to five fields:
1340 .Ar hisaddr Op Ar label Op Ar callback-number
1347 specify the client username and password.
1352 and PAP is being used,
1354 will look up the password database
1356 when authenticating.
1357 If the client does not offer a suitable response based on any
1358 .Ar name Ns No / Ns Ar key
1361 authentication fails.
1363 If authentication is successful,
1366 is used when negotiating IP numbers.
1369 command for details.
1371 If authentication is successful and
1373 is specified, the current system label is changed to match the given
1375 This will change the subsequent parsing of the
1381 If authentication is successful and
1387 the client will be called back on the given number.
1388 If CBCP is being used,
1390 may also contain a list of numbers or a
1395 The value will be used in
1397 subsequent CBCP phase.
1398 .Sh PPP OVER TCP and UDP (a.k.a Tunnelling)
1401 over a serial link, it is possible to
1402 use a TCP connection instead by specifying the host, port and protocol as the
1405 .Dl set device ui-gate:6669/tcp
1407 Instead of opening a serial device,
1409 will open a TCP connection to the given machine on the given
1411 It should be noted however that
1413 doesn't use the telnet protocol and will be unable to negotiate
1414 with a telnet server.
1415 You should set up a port for receiving this
1417 connection on the receiving machine (ui-gate).
1418 This is done by first updating
1420 to name the service:
1422 .Dl ppp-in 6669/tcp # Incoming PPP connections over TCP
1428 how to deal with incoming connections on that port:
1430 .Dl ppp-in stream tcp nowait root /usr/sbin/ppp ppp -direct ppp-in
1432 Don't forget to send a
1436 after you've updated
1437 .Pa /etc/inetd.conf .
1438 Here, we use a label named
1441 .Pa /etc/ppp/ppp.conf
1442 on ui-gate (the receiver) should contain the following:
1443 .Bd -literal -offset indent
1446 set ifaddr 10.0.4.1 10.0.4.2
1450 .Pa /etc/ppp/ppp.linkup
1452 .Bd -literal -offset indent
1454 add 10.0.1.0/24 HISADDR
1457 It is necessary to put the
1461 to ensure that the route is only added after
1463 has negotiated and assigned addresses to its interface.
1465 You may also want to enable PAP or CHAP for security.
1466 To enable PAP, add the following line:
1467 .Bd -literal -offset indent
1471 You'll also need to create the following entry in
1472 .Pa /etc/ppp/ppp.secret :
1473 .Bd -literal -offset indent
1474 MyAuthName MyAuthPasswd
1481 the password is looked up in the
1486 .Pa /etc/ppp/ppp.conf
1487 on awfulhak (the initiator) should contain the following:
1488 .Bd -literal -offset indent
1491 set device ui-gate:ppp-in/tcp
1494 set log Phase Chat Connect hdlc LCP IPCP IPV6CP CCP tun
1495 set ifaddr 10.0.4.2 10.0.4.1
1498 with the route setup in
1499 .Pa /etc/ppp/ppp.linkup :
1500 .Bd -literal -offset indent
1502 add 10.0.2.0/24 HISADDR
1505 Again, if you're enabling PAP, you'll also need this in the
1506 .Pa /etc/ppp/ppp.conf
1508 .Bd -literal -offset indent
1509 set authname MyAuthName
1510 set authkey MyAuthKey
1513 We're assigning the address of 10.0.4.1 to ui-gate, and the address
1514 10.0.4.2 to awfulhak.
1515 To open the connection, just type
1517 .Dl awfulhak # ppp -background ui-gate
1519 The result will be an additional "route" on awfulhak to the
1520 10.0.2.0/24 network via the TCP connection, and an additional
1521 "route" on ui-gate to the 10.0.1.0/24 network.
1522 The networks are effectively bridged - the underlying TCP
1523 connection may be across a public network (such as the
1526 traffic is conceptually encapsulated
1527 (although not packet by packet) inside the TCP stream between
1530 The major disadvantage of this mechanism is that there are two
1531 "guaranteed delivery" mechanisms in place - the underlying TCP
1532 stream and whatever protocol is used over the
1534 link - probably TCP again.
1535 If packets are lost, both levels will
1536 get in each others way trying to negotiate sending of the missing
1539 To avoid this overhead, it is also possible to do all this using
1540 UDP instead of TCP as the transport by simply changing the protocol
1541 from "tcp" to "udp".
1542 When using UDP as a transport,
1544 will operate in synchronous mode.
1545 This is another gain as the incoming
1546 data does not have to be rearranged into packets.
1548 Care should be taken when adding a default route through a tunneled
1550 It is quite common for the default route
1552 .Pa /etc/ppp/ppp.linkup )
1553 to end up routing the link's TCP connection through the tunnel,
1554 effectively garrotting the connection.
1555 To avoid this, make sure you add a static route for the benefit of
1557 .Bd -literal -offset indent
1560 set device ui-gate:ppp-in/tcp
1567 is the IP number that your route to
1571 When routing your connection across a public network such as the Internet,
1572 it is preferable to encrypt the data.
1573 This can be done with the help of the MPPE protocol, although currently this
1574 means that you will not be able to also compress the traffic as MPPE is
1575 implemented as a compression layer (thank Microsoft for this).
1576 To enable MPPE encryption, add the following lines to
1577 .Pa /etc/ppp/ppp.conf
1579 .Bd -literal -offset indent
1581 disable deflate pred1
1585 ensuring that you've put the requisite entry in
1586 .Pa /etc/ppp/ppp.secret
1587 (MSCHAPv2 is challenge based, so
1591 MSCHAPv2 and MPPE are accepted by default, so the client end should work
1592 without any additional changes (although ensure you have
1597 .Sh NETWORK ADDRESS TRANSLATION (PACKET ALIASING)
1600 command line option enables network address translation (a.k.a. packet
1604 host to act as a masquerading gateway for other computers over
1605 a local area network.
1606 Outgoing IP packets are NAT'd so that they appear to come from the
1608 host, and incoming packets are de-NAT'd so that they are routed
1609 to the correct machine on the local area network.
1610 NAT allows computers on private, unregistered subnets to have Internet
1611 access, although they are invisible from the outside world.
1614 operation should first be verified with network address translation disabled.
1617 option should be switched on, and network applications (web browser,
1622 should be checked on the
1625 Finally, the same or similar applications should be checked on other
1626 computers in the LAN.
1627 If network applications work correctly on the
1629 host, but not on other machines in the LAN, then the masquerading
1630 software is working properly, but the host is either not forwarding
1631 or possibly receiving IP packets.
1632 Check that IP forwarding is enabled in
1634 and that other machines have designated the
1636 host as the gateway for the LAN.
1637 .Sh PACKET FILTERING
1638 This implementation supports packet filtering.
1639 There are four kinds of
1649 Here are the basics:
1652 A filter definition has the following syntax:
1661 .Ar src_addr Ns Op / Ns Ar width
1662 .Op Ar dst_addr Ns Op / Ns Ar width
1664 .Ar [ proto Op src Ar cmp port
1669 .Op timeout Ar secs ]
1681 is a numeric value between
1685 specifying the rule number.
1686 Rules are specified in numeric order according to
1697 in which case, if a given packet matches the rule, the associated action
1698 is taken immediately.
1700 can also be specified as
1702 to clear the action associated with that particular rule, or as a new
1703 rule number greater than the current rule.
1704 In this case, if a given
1705 packet matches the current rule, the packet will next be matched against
1706 the new rule number (rather than the next rule number).
1710 may optionally be followed with an exclamation mark
1714 to reverse the sense of the following match.
1716 .Op Ar src_addr Ns Op / Ns Ar width
1718 .Op Ar dst_addr Ns Op / Ns Ar width
1719 are the source and destination IP number specifications.
1722 is specified, it gives the number of relevant netmask bits,
1723 allowing the specification of an address range.
1729 may be given the values
1735 (refer to the description of the
1737 command for a description of these values).
1738 When these values are used,
1739 the filters will be updated any time the values change.
1740 This is similar to the behaviour of the
1745 may be any protocol from
1754 meaning less-than, equal and greater-than respectively.
1756 can be specified as a numeric port or by service name from
1764 flags are only allowed when
1768 and represent the TH_ACK, TH_SYN and TH_FIN or TH_RST TCP flags respectively.
1770 The timeout value adjusts the current idle timeout to at least
1773 If a timeout is given in the alive filter as well as in the in/out
1774 filter, the in/out value is used.
1775 If no timeout is given, the default timeout (set using
1777 and defaulting to 180 seconds) is used.
1780 Each filter can hold up to 40 rules, starting from rule 0.
1781 The entire rule set is not effective until rule 0 is defined,
1782 i.e., the default is to allow everything through.
1784 If no rule in a defined set of rules matches a packet, that packet will
1785 be discarded (blocked).
1786 If there are no rules in a given filter, the packet will be permitted.
1788 It's possible to filter based on the payload of UDP frames where those
1794 .Ar filter-decapsulation
1795 option below for further details.
1798 .Dq set filter Ar name No -1
1803 .Pa /usr/share/examples/ppp/ppp.conf.sample .
1804 .Sh SETTING THE IDLE TIMER
1805 To check/set the idle timer, use the
1810 .Bd -literal -offset indent
1811 ppp ON awfulhak> set timeout 600
1814 The timeout period is measured in seconds, the default value for which
1817 To disable the idle timer function, use the command
1818 .Bd -literal -offset indent
1819 ppp ON awfulhak> set timeout 0
1826 modes, the idle timeout is ignored.
1829 mode, when the idle timeout causes the
1834 program itself remains running.
1835 Another trigger packet will cause it to attempt to re-establish the link.
1836 .Sh PREDICTOR-1 and DEFLATE COMPRESSION
1838 supports both Predictor type 1 and deflate compression.
1841 will attempt to use (or be willing to accept) both compression protocols
1842 when the peer agrees
1844 The deflate protocol is preferred by
1850 commands if you wish to disable this functionality.
1852 It is possible to use a different compression algorithm in each direction
1853 by using only one of
1857 (assuming that the peer supports both algorithms).
1859 By default, when negotiating DEFLATE,
1861 will use a window size of 15.
1864 command if you wish to change this behaviour.
1866 A special algorithm called DEFLATE24 is also available, and is disabled
1867 and denied by default.
1868 This is exactly the same as DEFLATE except that
1869 it uses CCP ID 24 to negotiate.
1872 to successfully negotiate DEFLATE with
1875 .Sh CONTROLLING IP ADDRESS
1878 uses IPCP to negotiate IP addresses.
1879 Each side of the connection
1880 specifies the IP address that it's willing to use, and if the requested
1881 IP address is acceptable then
1883 returns an ACK to the requester.
1886 returns NAK to suggest that the peer use a different IP address.
1888 both sides of the connection agree to accept the received request (and
1889 send an ACK), IPCP is set to the open state and a network level connection
1891 To control this IPCP behaviour, this implementation has the
1893 command for defining the local and remote IP address:
1894 .Bd -ragged -offset indent
1895 .No set ifaddr Oo Ar src_addr Ns
1897 .Oo Ar dst_addr Ns Op / Ns Ar \&nn
1907 is the IP address that the local side is willing to use,
1909 is the IP address which the remote side should use and
1911 is the netmask that should be used.
1913 defaults to the current
1916 defaults to 0.0.0.0, and
1918 defaults to whatever mask is appropriate for
1920 It is only possible to make
1922 smaller than the default.
1923 The usual value is 255.255.255.255, as
1924 most kernels ignore the netmask of a POINTOPOINT interface.
1928 implementations require that the peer negotiates a specific IP
1931 If this is the case,
1933 may be used to specify this IP number.
1934 This will not affect the
1935 routing table unless the other side agrees with this proposed number.
1936 .Bd -literal -offset indent
1937 set ifaddr 192.244.177.38 192.244.177.2 255.255.255.255 0.0.0.0
1940 The above specification means:
1942 .Bl -bullet -compact
1944 I will first suggest that my IP address should be 0.0.0.0, but I
1945 will only accept an address of 192.244.177.38.
1947 I strongly insist that the peer uses 192.244.177.2 as his own
1948 address and won't permit the use of any IP address but 192.244.177.2.
1949 When the peer requests another IP address, I will always suggest that
1950 it uses 192.244.177.2.
1952 The routing table entry will have a netmask of 0xffffffff.
1955 This is all fine when each side has a pre-determined IP address, however
1956 it is often the case that one side is acting as a server which controls
1957 all IP addresses and the other side should go along with it.
1958 In order to allow more flexible behaviour, the
1960 command allows the user to specify IP addresses more loosely:
1962 .Dl set ifaddr 192.244.177.38/24 192.244.177.2/20
1964 A number followed by a slash
1966 represents the number of bits significant in the IP address.
1967 The above example means:
1969 .Bl -bullet -compact
1971 I'd like to use 192.244.177.38 as my address if it is possible, but I'll
1972 also accept any IP address between 192.244.177.0 and 192.244.177.255.
1974 I'd like to make him use 192.244.177.2 as his own address, but I'll also
1975 permit him to use any IP address between 192.244.176.0 and
1978 As you may have already noticed, 192.244.177.2 is equivalent to saying
1981 As an exception, 0 is equivalent to 0.0.0.0/0, meaning that I have no
1982 preferred IP address and will obey the remote peers selection.
1983 When using zero, no routing table entries will be made until a connection
1986 192.244.177.2/0 means that I'll accept/permit any IP address but I'll
1987 suggest that 192.244.177.2 be used first.
1990 When negotiating IPv6 addresses, no control is given to the user.
1991 IPV6CP negotiation is fully automatic.
1992 .Sh CONNECTING WITH YOUR INTERNET SERVICE PROVIDER
1993 The following steps should be taken when connecting to your ISP:
1996 Describe your providers phone number(s) in the dial script using the
1999 This command allows you to set multiple phone numbers for
2000 dialing and redialing separated by either a pipe
2004 .Bd -ragged -offset indent
2005 .No set phone Ar telno Ns Xo
2006 .Oo \&| Ns Ar backupnumber
2007 .Oc Ns ... Ns Oo : Ns Ar nextnumber
2012 Numbers after the first in a pipe-separated list are only used if the
2013 previous number was used in a failed dial or login script.
2015 separated by a colon are used sequentially, irrespective of what happened
2016 as a result of using the previous number.
2018 .Bd -literal -offset indent
2019 set phone "1234567|2345678:3456789|4567890"
2022 Here, the 1234567 number is attempted.
2023 If the dial or login script fails,
2024 the 2345678 number is used next time, but *only* if the dial or login script
2026 On the dial after this, the 3456789 number is used.
2028 number is only used if the dial or login script using the 3456789 fails.
2029 If the login script of the 2345678 number fails, the next number is still the
2031 As many pipes and colons can be used as are necessary
2032 (although a given site would usually prefer to use either the pipe or the
2033 colon, but not both).
2034 The next number redial timeout is used between all numbers.
2035 When the end of the list is reached, the normal redial period is
2036 used before starting at the beginning again.
2037 The selected phone number is substituted for the \\\\T string in the
2039 command (see below).
2041 Set up your redial requirements using
2043 For example, if you have a bad telephone line or your provider is
2044 usually engaged (not so common these days), you may want to specify
2046 .Bd -literal -offset indent
2050 This says that up to 4 phone calls should be attempted with a pause of 10
2051 seconds before dialing the first number again.
2053 Describe your login procedure using the
2060 command is used to talk to your modem and establish a link with your
2062 .Bd -literal -offset indent
2063 set dial "ABORT BUSY ABORT NO\\\\sCARRIER TIMEOUT 4 \\"\\" \e
2064 ATZ OK-ATZ-OK ATDT\\\\T TIMEOUT 60 CONNECT"
2067 This modem "chat" string means:
2070 Abort if the string "BUSY" or "NO CARRIER" are received.
2072 Set the timeout to 4 seconds.
2079 If that's not received within the 4 second timeout, send ATZ
2082 Send ATDTxxxxxxx where xxxxxxx is the next number in the phone list from
2085 Set the timeout to 60.
2087 Wait for the CONNECT string.
2090 Once the connection is established, the login script is executed.
2091 This script is written in the same style as the dial script, but care should
2092 be taken to avoid having your password logged:
2093 .Bd -literal -offset indent
2094 set authkey MySecret
2095 set login "TIMEOUT 15 login:-\\\\r-login: awfulhak \e
2096 word: \\\\P ocol: PPP HELLO"
2099 This login "chat" string means:
2102 Set the timeout to 15 seconds.
2105 If it's not received, send a carriage return and expect
2110 Expect "word:" (the tail end of a "Password:" prompt).
2112 Send whatever our current
2116 Expect "ocol:" (the tail end of a "Protocol:" prompt).
2125 command is logged specially.
2130 logging is enabled, the actual password is not logged;
2134 Login scripts vary greatly between ISPs.
2135 If you're setting one up for the first time,
2136 .Em ENABLE CHAT LOGGING
2137 so that you can see if your script is behaving as you expect.
2143 to specify your serial line and speed, for example:
2144 .Bd -literal -offset indent
2145 set device /dev/cuaa0
2149 Cuaa0 is the first serial port on
2156 A speed of 115200 should be specified
2157 if you have a modem capable of bit rates of 28800 or more.
2158 In general, the serial speed should be about four times the modem speed.
2162 command to {define} the IP address.
2165 If you know what IP address your provider uses, then use it as the remote
2166 address (dst_addr), otherwise choose something like 10.0.0.2/0 (see below).
2168 If your provider has assigned a particular IP address to you, then use
2169 it as your address (src_addr).
2171 If your provider assigns your address dynamically, choose a suitably
2172 unobtrusive and unspecific IP number as your address.
2173 10.0.0.1/0 would be appropriate.
2174 The bit after the / specifies how many bits of the
2175 address you consider to be important, so if you wanted to insist on
2176 something in the class C network 1.2.3.0, you could specify 1.2.3.1/24.
2178 If you find that your ISP accepts the first IP number that you suggest,
2179 specify third and forth arguments of
2181 This will force your ISP to assign a number.
2182 (The third argument will
2183 be ignored as it is less restrictive than the default mask for your
2187 An example for a connection where you don't know your IP number or your
2188 ISPs IP number would be:
2189 .Bd -literal -offset indent
2190 set ifaddr 10.0.0.1/0 10.0.0.2/0 0.0.0.0 0.0.0.0
2193 In most cases, your ISP will also be your default router.
2194 If this is the case, add the line
2195 .Bd -literal -offset indent
2200 .Pa /etc/ppp/ppp.conf
2202 .Pa /etc/ppp/ppp.linkup
2203 for setups that don't use
2209 to add a default route to whatever the peer address is
2210 (10.0.0.2 in this example).
2213 meaning that should the value of
2215 change, the route will be updated accordingly.
2217 If your provider requests that you use PAP/CHAP authentication methods, add
2218 the next lines to your
2219 .Pa /etc/ppp/ppp.conf
2221 .Bd -literal -offset indent
2223 set authkey MyPassword
2226 Both are accepted by default, so
2228 will provide whatever your ISP requires.
2230 It should be noted that a login script is rarely (if ever) required
2231 when PAP or CHAP are in use.
2233 Ask your ISP to authenticate your nameserver address(es) with the line
2234 .Bd -literal -offset indent
2240 do this if you are running a local DNS unless you also either use
2245 .Pa /etc/ppp/ppp.linkdown ,
2248 will simply circumvent its use by entering some nameserver lines in
2249 .Pa /etc/resolv.conf .
2253 .Pa /usr/share/examples/ppp/ppp.conf.sample
2255 .Pa /usr/share/examples/ppp/ppp.linkup.sample
2256 for some real examples.
2257 The pmdemand label should be appropriate for most ISPs.
2258 .Sh LOGGING FACILITY
2260 is able to generate the following log info either via
2262 or directly to the screen:
2264 .Bl -tag -width XXXXXXXXX -offset XXX -compact
2266 Enable all logging facilities.
2267 This generates a lot of log.
2268 The most common use of 'all' is as a basis, where you remove some facilities
2269 after enabling 'all' ('debug' and 'timer' are usually best disabled.)
2271 Dump async level packet in hex.
2273 Generate CBCP (CallBack Control Protocol) logs.
2275 Generate a CCP packet trace.
2283 chat script trace logs.
2285 Log commands executed either from the command line or any of the configuration
2288 Log Chat lines containing the string "CONNECT".
2290 Log debug information.
2292 Log DNS QUERY packets.
2294 Log packets permitted by the dial filter and denied by any filter.
2296 Dump HDLC packet in hex.
2298 Log all function calls specifically made as user id 0.
2300 Generate an IPCP packet trace.
2302 Generate an LCP packet trace.
2304 Generate LQR reports.
2306 Phase transition log output.
2308 Dump physical level packet in hex.
2310 Dump sync level packet in hex.
2312 Dump all TCP/IP packets.
2314 Log timer manipulation.
2316 Include the tun device on each log line.
2318 Output to the terminal device.
2319 If there is currently no terminal,
2320 output is sent to the log file using syslogs
2323 Output to both the terminal device
2324 and the log file using syslogs
2327 Output to the log file using
2333 command allows you to set the logging output level.
2334 Multiple levels can be specified on a single command line.
2335 The default is equivalent to
2338 It is also possible to log directly to the screen.
2339 The syntax is the same except that the word
2341 should immediately follow
2345 (i.e., only the un-maskable warning, error and alert output).
2347 If The first argument to
2348 .Dq set log Op local
2353 character, the current log levels are
2354 not cleared, for example:
2355 .Bd -literal -offset indent
2356 PPP ON awfulhak> set log phase
2357 PPP ON awfulhak> show log
2358 Log: Phase Warning Error Alert
2359 Local: Warning Error Alert
2360 PPP ON awfulhak> set log +tcp/ip -warning
2361 PPP ON awfulhak> set log local +command
2362 PPP ON awfulhak> show log
2363 Log: Phase TCP/IP Warning Error Alert
2364 Local: Command Warning Error Alert
2367 Log messages of level Warning, Error and Alert are not controllable
2369 .Dq set log Op local .
2373 level is special in that it will not be logged if it can be displayed
2377 deals with the following signals:
2378 .Bl -tag -width "USR2"
2380 Receipt of this signal causes the termination of the current connection
2384 to exit unless it is in
2389 .It HUP, TERM & QUIT
2396 to re-open any existing server socket, dropping all existing diagnostic
2398 Sockets that couldn't previously be opened will be retried.
2402 to close any existing server socket, dropping all existing diagnostic
2405 can still be used to re-open the socket.
2408 If you wish to use more than one physical link to connect to a
2410 peer, that peer must also understand the
2413 Refer to RFC 1990 for specification details.
2415 The peer is identified using a combination of his
2416 .Dq endpoint discriminator
2418 .Dq authentication id .
2419 Either or both of these may be specified.
2420 It is recommended that
2421 at least one is specified, otherwise there is no way of ensuring that
2422 all links are actually connected to the same peer program, and some
2423 confusing lock-ups may result.
2424 Locally, these identification variables are specified using the
2433 must be agreed in advance with the peer.
2435 Multi-link capabilities are enabled using the
2437 command (set maximum reconstructed receive unit).
2438 Once multi-link is enabled,
2440 will attempt to negotiate a multi-link connection with the peer.
2442 By default, only one
2447 To create more links, the
2450 This command will clone existing links, where all
2451 characteristics are the same except:
2454 The new link has its own name as specified on the
2461 Its mode may subsequently be changed using the
2465 The new link is in a
2470 A summary of all available links can be seen using the
2474 Once a new link has been created, command usage varies.
2475 All link specific commands must be prefixed with the
2477 command, specifying on which link the command is to be applied.
2478 When only a single link is available,
2480 is smart enough not to require the
2484 Some commands can still be used without specifying a link - resulting
2485 in an operation at the
2488 For example, once two or more links are available, the command
2490 will show CCP configuration and statistics at the multi-link level, and
2491 .Dq link deflink show ccp
2492 will show the same information at the
2496 Armed with this information, the following configuration might be used:
2497 .Bd -literal -offset indent
2501 set device /dev/cuaa0 /dev/cuaa1 /dev/cuaa2
2502 set phone "123456789"
2503 set dial "ABORT BUSY ABORT NO\\sCARRIER TIMEOUT 5 \\"\\" ATZ \e
2504 OK-AT-OK \\\\dATDT\\\\T TIMEOUT 45 CONNECT"
2506 set ifaddr 10.0.0.1/0 10.0.0.2/0 0.0.0.0 0.0.0.0
2508 set authkey ppppassword
2511 clone 1,2,3 # Create 3 new links - duplicates of the default
2512 link deflink remove # Delete the default link (called ``deflink'')
2515 Note how all cloning is done at the end of the configuration.
2516 Usually, the link will be configured first, then cloned.
2517 If you wish all links
2518 to be up all the time, you can add the following line to the end of your
2520 .Bd -literal -offset indent
2521 link 1,2,3 set mode ddial
2524 If you want the links to dial on demand, this command could be used:
2525 .Bd -literal -offset indent
2526 link * set mode auto
2529 Links may be tied to specific names by removing the
2531 line above, and specifying the following after the
2534 .Bd -literal -offset indent
2535 link 1 set device /dev/cuaa0
2536 link 2 set device /dev/cuaa1
2537 link 3 set device /dev/cuaa2
2542 command to see which commands require context (using the
2544 command), which have optional
2545 context and which should not have any context.
2551 mode with the peer, it creates a local domain socket in the
2554 This socket is used to pass link information (including
2555 the actual link file descriptor) between different
2560 ability to be run from a
2566 capability), without needing to have initial control of the serial
2570 negotiates multi-link mode, it will pass its open link to any
2571 already running process.
2572 If there is no already running process,
2574 will act as the master, creating the socket and listening for new
2576 .Sh PPP COMMAND LIST
2577 This section lists the available commands and their effect.
2578 They are usable either from an interactive
2580 session, from a configuration file or from a
2586 .It accept|deny|enable|disable Ar option....
2587 These directives tell
2589 how to negotiate the initial connection with the peer.
2592 has a default of either accept or deny and enable or disable.
2594 means that the option will be ACK'd if the peer asks for it.
2596 means that the option will be NAK'd if the peer asks for it.
2598 means that the option will be requested by us.
2600 means that the option will not be requested by us.
2603 may be one of the following:
2606 Default: Enabled and Accepted.
2607 ACFComp stands for Address and Control Field Compression.
2608 Non LCP packets will usually have an address
2609 field of 0xff (the All-Stations address) and a control field of
2610 0x03 (the Unnumbered Information command).
2612 negotiated, these two bytes are simply not sent, thus minimising
2619 Default: Disabled and Accepted.
2620 CHAP stands for Challenge Handshake Authentication Protocol.
2621 Only one of CHAP and PAP (below) may be negotiated.
2622 With CHAP, the authenticator sends a "challenge" message to its peer.
2623 The peer uses a one-way hash function to encrypt the
2624 challenge and sends the result back.
2625 The authenticator does the same, and compares the results.
2626 The advantage of this mechanism is that no
2627 passwords are sent across the connection.
2628 A challenge is made when the connection is first made.
2629 Subsequent challenges may occur.
2630 If you want to have your peer authenticate itself, you must
2633 .Pa /etc/ppp/ppp.conf ,
2634 and have an entry in
2635 .Pa /etc/ppp/ppp.secret
2638 When using CHAP as the client, you need only specify
2643 .Pa /etc/ppp/ppp.conf .
2644 CHAP is accepted by default.
2647 implementations use "MS-CHAP" rather than MD5 when encrypting the
2649 MS-CHAP is a combination of MD4 and DES.
2652 was built on a machine with DES libraries available, it will respond
2653 to MS-CHAP authentication requests, but will never request them.
2655 Default: Enabled and Accepted.
2656 This option decides if deflate
2657 compression will be used by the Compression Control Protocol (CCP).
2658 This is the same algorithm as used by the
2661 Note: There is a problem negotiating
2667 implementation available under many operating systems.
2669 (version 2.3.1) incorrectly attempts to negotiate
2671 compression using type
2673 as the CCP configuration type rather than type
2679 is actually specified as
2680 .Dq PPP Magna-link Variable Resource Compression
2684 is capable of negotiating with
2691 .Ar accept Ns No ed .
2693 Default: Disabled and Denied.
2694 This is a variance of the
2696 option, allowing negotiation with the
2701 section above for details.
2702 It is disabled by default as it violates
2705 Default: Disabled and Denied.
2706 This option allows DNS negotiation.
2711 will request that the peer confirms the entries in
2712 .Pa /etc/resolv.conf .
2713 If the peer NAKs our request (suggesting new IP numbers),
2714 .Pa /etc/resolv.conf
2715 is updated and another request is sent to confirm the new entries.
2718 .Dq accept Ns No ed,
2720 will answer any DNS queries requested by the peer rather than rejecting
2722 The answer is taken from
2723 .Pa /etc/resolv.conf
2726 command is used as an override.
2728 Default: Enabled and Accepted.
2729 This option allows control over whether we
2730 negotiate an endpoint discriminator.
2731 We only send our discriminator if
2736 We reject the peers discriminator if
2740 Default: Disabled and Accepted.
2741 The use of this authentication protocol
2742 is discouraged as it partially violates the authentication protocol by
2743 implementing two different mechanisms (LANMan & NT) under the guise of
2744 a single CHAP type (0x80).
2746 uses a simple DES encryption mechanism and is the least secure of the
2747 CHAP alternatives (although is still more secure than PAP).
2751 description below for more details.
2753 Default: Disabled and Accepted.
2754 This option decides if Link Quality Requests will be sent or accepted.
2755 LQR is a protocol that allows
2757 to determine that the link is down without relying on the modems
2759 When LQR is enabled,
2765 below) as part of the LCP request.
2766 If the peer agrees, both sides will
2767 exchange LQR packets at the agreed frequency, allowing detailed link
2768 quality monitoring by enabling LQM logging.
2769 If the peer doesn't agree,
2771 will send ECHO LQR requests instead.
2772 These packets pass no information of interest, but they
2774 be replied to by the peer.
2776 Whether using LQR or ECHO LQR,
2778 will abruptly drop the connection if 5 unacknowledged packets have been
2779 sent rather than sending a 6th.
2780 A message is logged at the
2782 level, and any appropriate
2784 values are honoured as if the peer were responsible for dropping the
2787 Default: Enabled and Accepted.
2788 This is Microsoft Point to Point Encryption scheme.
2789 MPPE key size can be
2790 40-, 56- and 128-bits.
2795 Default: Disabled and Accepted.
2796 It is very similar to standard CHAP (type 0x05)
2797 except that it issues challenges of a fixed 16 bytes in length and uses a
2798 combination of MD4, SHA-1 and DES to encrypt the challenge rather than using the
2799 standard MD5 mechanism.
2801 Default: Disabled and Accepted.
2802 The use of this authentication protocol
2803 is discouraged as it partially violates the authentication protocol by
2804 implementing two different mechanisms (LANMan & NT) under the guise of
2805 a single CHAP type (0x80).
2806 It is very similar to standard CHAP (type 0x05)
2807 except that it issues challenges of a fixed 8 bytes in length and uses a
2808 combination of MD4 and DES to encrypt the challenge rather than using the
2809 standard MD5 mechanism.
2810 CHAP type 0x80 for LANMan is also supported - see
2818 use CHAP type 0x80, when acting as authenticator with both
2819 .Dq enable Ns No d ,
2821 will rechallenge the peer up to three times if it responds using the wrong
2822 one of the two protocols.
2823 This gives the peer a chance to attempt using both protocols.
2827 acts as the authenticatee with both protocols
2828 .Dq accept Ns No ed ,
2829 the protocols are used alternately in response to challenges.
2831 Note: If only LANMan is enabled,
2833 (version 2.3.5) misbehaves when acting as authenticatee.
2835 the NT and the LANMan answers, but also suggests that only the NT answer
2838 Default: Disabled and Accepted.
2839 PAP stands for Password Authentication Protocol.
2840 Only one of PAP and CHAP (above) may be negotiated.
2841 With PAP, the ID and Password are sent repeatedly to the peer until
2842 authentication is acknowledged or the connection is terminated.
2843 This is a rather poor security mechanism.
2844 It is only performed when the connection is first established.
2845 If you want to have your peer authenticate itself, you must
2848 .Pa /etc/ppp/ppp.conf ,
2849 and have an entry in
2850 .Pa /etc/ppp/ppp.secret
2851 for the peer (although see the
2857 When using PAP as the client, you need only specify
2862 .Pa /etc/ppp/ppp.conf .
2863 PAP is accepted by default.
2865 Default: Enabled and Accepted.
2866 This option decides if Predictor 1
2867 compression will be used by the Compression Control Protocol (CCP).
2869 Default: Enabled and Accepted.
2870 This option is used to negotiate
2871 PFC (Protocol Field Compression), a mechanism where the protocol
2872 field number is reduced to one octet rather than two.
2874 Default: Enabled and Accepted.
2875 This option determines if
2877 will request and accept requests for short
2879 sequence numbers when negotiating multi-link mode.
2880 This is only applicable if our MRRU is set (thus enabling multi-link).
2882 Default: Enabled and Accepted.
2883 This option determines if Van Jacobson header compression will be used.
2886 The following options are not actually negotiated with the peer.
2887 Therefore, accepting or denying them makes no sense.
2889 .It filter-decapsulation
2891 When this option is enabled,
2893 will examine UDP frames to see if they actually contain a
2895 frame as their payload.
2896 If this is the case, all filters will operate on the payload rather
2897 than the actual packet.
2899 This is useful if you want to send PPPoUDP traffic over a
2901 link, but want that link to do smart things with the real data rather than
2904 The UDP frame payload must not be compressed in any way, otherwise
2906 will not be able to interpret it.
2907 It's therefore recommended that you
2908 .Ic disable vj pred1 deflate
2910 .Ic deny vj pred1 deflate
2911 in the configuration for the
2913 invocation with the udp link.
2918 exchanges low-level LCP, CCP and IPCP configuration traffic, the
2920 field of any replies is expected to be the same as that of the request.
2923 drops any reply packets that do not contain the expected identifier
2924 field, reporting the fact at the respective log level.
2929 will ignore the identifier field.
2934 This option simply tells
2936 to add new interface addresses to the interface rather than replacing them.
2937 The option can only be enabled if network address translation is enabled
2938 .Pq Dq nat enable yes .
2940 With this option enabled,
2942 will pass traffic for old interface addresses through the NAT
2943 ifdef({LOCALNAT},{engine,},{engine
2945 .Xr libalias 3 ) ,})
2946 resulting in the ability (in
2948 mode) to properly connect the process that caused the PPP link to
2949 come up in the first place.
2959 to attempt to negotiate IP control protocol capabilities and if
2960 successful to exchange IP datagrams with the peer.
2965 to attempt to negotiate IPv6 control protocol capabilities and if
2966 successful to exchange IPv6 datagrams with the peer.
2971 runs as a Multi-link server, a different
2973 instance initially receives each connection.
2974 After determining that
2975 the link belongs to an already existing bundle (controlled by another
2979 will transfer the link to that process.
2981 If the link is a tty device or if this option is enabled,
2983 will not exit, but will change its process name to
2985 and wait for the controlling
2987 to finish with the link and deliver a signal back to the idle process.
2988 This prevents the confusion that results from
2990 parent considering the link resource available again.
2992 For tty devices that have entries in
2994 this is necessary to prevent another
2996 from being started, and for program links such as
3000 from exiting due to the death of its child.
3003 cannot determine its parents requirements (except for the tty case), this
3004 option must be enabled manually depending on the circumstances.
3011 will automatically loop back packets being sent
3012 out with a destination address equal to that of the
3017 will send the packet, probably resulting in an ICMP redirect from
3019 It is convenient to have this option enabled when
3020 the interface is also the default route as it avoids the necessity
3021 of a loopback route.
3024 Enabling this option will tell the PAP authentication
3025 code to use the password database (see
3027 to authenticate the caller if they cannot be found in the
3028 .Pa /etc/ppp/ppp.secret
3030 .Pa /etc/ppp/ppp.secret
3031 is always checked first.
3032 If you wish to use passwords from
3034 but also to specify an IP number or label for a given client, use
3036 as the client password in
3037 .Pa /etc/ppp/ppp.secret .
3040 Enabling this option will tell
3042 to proxy ARP for the peer.
3045 will make an entry in the ARP table using
3049 address of the local network in which
3052 This allows other machines connected to the LAN to talk to
3053 the peer as if the peer itself was connected to the LAN.
3054 The proxy entry cannot be made unless
3056 is an address from a LAN.
3059 Enabling this will tell
3061 to add proxy arp entries for every IP address in all class C or
3062 smaller subnets routed via the tun interface.
3064 Proxy arp entries are only made for sticky routes that are added
3068 No proxy arp entries are made for the interface address itself
3076 command is used with the
3082 values, entries are stored in the
3085 Each time these variables change, this list is re-applied to the routing table.
3087 Disabling this option will prevent the re-application of sticky routes,
3090 list will still be maintained.
3097 to adjust TCP SYN packets so that the maximum receive segment
3098 size is not greater than the amount allowed by the interface MTU.
3103 to gather throughput statistics.
3104 Input and output is sampled over
3105 a rolling 5 second window, and current, best and total figures are retained.
3106 This data is output when the relevant
3108 layer shuts down, and is also available using the
3111 Throughput statistics are available at the
3118 Normally, when a user is authenticated using PAP or CHAP, and when
3122 mode, an entry is made in the utmp and wtmp files for that user.
3123 Disabling this option will tell
3125 not to make any utmp or wtmp entries.
3126 This is usually only necessary if
3127 you require the user to both login and authenticate themselves.
3131 .Ar dest Ns Op / Ns Ar nn
3136 is the destination IP address.
3137 The netmask is specified either as a number of bits with
3139 or as an IP number using
3144 with no mask refers to the default route.
3145 It is also possible to use the literal name
3150 is the next hop gateway to get to the given
3155 command for further details.
3157 It is possible to use the symbolic names
3163 as the destination, and
3170 is replaced with the interface IP address,
3172 is replaced with the interface IP destination (peer) address,
3174 is replaced with the interface IPv6 address, and
3176 is replaced with the interface IPv6 destination address,
3183 then if the route already exists, it will be updated as with the
3187 for further details).
3189 Routes that contain the
3197 constants are considered
3199 They are stored in a list (use
3201 to see the list), and each time the value of one of these variables
3202 changes, the appropriate routing table entries are updated.
3203 This facility may be disabled using
3204 .Dq disable sroutes .
3205 .It allow Ar command Op Ar args
3206 This command controls access to
3208 and its configuration files.
3209 It is possible to allow user-level access,
3210 depending on the configuration file label and on the mode that
3213 For example, you may wish to configure
3223 User id 0 is immune to these commands.
3225 .It allow user Ns Xo
3227 .Ar logname Ns No ...
3229 By default, only user id 0 is allowed access to
3231 If this command is used, all of the listed users are allowed access to
3232 the section in which the
3237 section is always checked first (even though it is only ever automatically
3240 commands are cumulative in a given section, but users allowed in any given
3241 section override users allowed in the default section, so it's possible to
3242 allow users access to everything except a given label by specifying default
3245 section, and then specifying a new user list for that label.
3249 is specified, access is allowed to all users.
3250 .It allow mode Ns Xo
3254 By default, access using any
3257 If this command is used, it restricts the access
3259 allowed to load the label under which this command is specified.
3264 command overrides any previous settings, and the
3266 section is always checked first.
3278 When running in multi-link mode, a section can be loaded if it allows
3280 of the currently existing line modes.
3282 .It nat Ar command Op Ar args
3283 This command allows the control of the network address translation (also
3284 known as masquerading or IP aliasing) facilities that are built into
3286 NAT is done on the external interface only, and is unlikely to make sense
3291 If nat is enabled on your system (it may be omitted at compile time),
3292 the following commands are possible:
3294 .It nat enable yes|no
3295 This command either switches network address translation on or turns it off.
3298 command line flag is synonymous with
3299 .Dq nat enable yes .
3300 .It nat addr Op Ar addr_local addr_alias
3301 This command allows data for
3305 It is useful if you own a small number of real IP numbers that
3306 you wish to map to specific machines behind your gateway.
3307 .It nat deny_incoming yes|no
3308 If set to yes, this command will refuse all incoming packets where an
3309 aliasing link doesn't already exist.
3310 ifdef({LOCALNAT},{},{Refer to the
3311 .Sx CONCEPTUAL BACKGROUND
3314 for a description of what an
3319 It should be noted under what circumstances an aliasing link is
3320 ifdef({LOCALNAT},{created.},{created by
3322 It may be necessary to further protect your network from outside
3323 connections using the
3329 This command gives a summary of available nat commands.
3331 This option causes various NAT statistics and information to
3332 be logged to the file
3333 .Pa /var/log/alias.log .
3334 .It nat port Ar proto Ar targetIP Ns Xo
3335 .No : Ns Ar targetPort Ns
3337 .No - Ns Ar targetPort
3340 .No - Ns Ar aliasPort
3341 .Oc Oo Ar remoteIP : Ns
3344 .No - Ns Ar remotePort
3348 This command causes incoming
3362 A range of port numbers may be specified as shown above.
3363 The ranges must be of the same size.
3367 is specified, only data coming from that IP number is redirected.
3371 (indicating any source port)
3372 or a range of ports the same size as the other ranges.
3374 This option is useful if you wish to run things like Internet phone on
3375 machines behind your gateway, but is limited in that connections to only
3376 one interior machine per source machine and target port are possible.
3377 .It nat proto Ar proto localIP Oo
3378 .Ar publicIP Op Ar remoteIP
3382 to redirect packets of protocol type
3386 to the internal address
3391 is specified, only packets destined for that address are matched,
3392 otherwise the default alias address is used.
3396 is specified, only packets matching that source address are matched,
3398 This command is useful for redirecting tunnel endpoints to an internal machine,
3401 .Dl nat proto ipencap 10.0.0.1
3402 .It "nat proxy cmd" Ar arg Ns No ...
3405 to proxy certain connections, redirecting them to a given server.
3406 ifdef({LOCALNAT},{},{Refer to the description of
3407 .Fn PacketAliasProxyRule
3410 for details of the available commands.
3412 .It nat punch_fw Op Ar base count
3415 to punch holes in the firewall for FTP or IRC DCC connections.
3416 This is done dynamically by installing temporary firewall rules which
3417 allow a particular connection (and only that connection) to go through
3419 The rules are removed once the corresponding connection terminates.
3423 rules starting from rule number
3425 will be used for punching firewall holes.
3426 The range will be cleared when the
3430 If no arguments are given, firewall punching is disabled.
3431 .It nat same_ports yes|no
3432 When enabled, this command will tell the network address translation engine to
3433 attempt to avoid changing the port number on outgoing packets.
3435 if you want to support protocols such as RPC and LPD which require
3436 connections to come from a well known port.
3437 .It nat target Op Ar address
3438 Set the given target address or clear it if no address is given.
3439 The target address is used
3440 ifdef({LOCALNAT},{},{by libalias })dnl
3441 to specify how to NAT incoming packets by default.
3442 If a target address is not set or if
3444 is given, packets are not altered and are allowed to route to the internal
3447 The target address may be set to
3450 ifdef({LOCALNAT},{all packets will be redirected},
3451 {libalias will redirect all packets})
3452 to the interface address.
3453 .It nat use_sockets yes|no
3454 When enabled, this option tells the network address translation engine to
3455 create a socket so that it can guarantee a correct incoming ftp data or
3457 .It nat unregistered_only yes|no
3458 Only alter outgoing packets with an unregistered source address.
3459 According to RFC 1918, unregistered source addresses
3460 are 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16.
3463 These commands are also discussed in the file
3465 which comes with the source distribution.
3471 is executed in the background with the following words replaced:
3472 .Bl -tag -width COMPILATIONDATE
3474 This is replaced with the local
3480 .It Li COMPILATIONDATE
3481 This is replaced with the date on which
3485 These are replaced with the primary and secondary nameserver IP numbers.
3486 If nameservers are negotiated by IPCP, the values of these macros will change.
3488 This is replaced with the local endpoint discriminator value.
3493 This is replaced with the peers IP number.
3495 This is replaced with the peers IPv6 number.
3497 This is replaced with the name of the interface that's in use.
3499 This is replaced with the number of IP bytes received since the connection
3502 This is replaced with the number of IP bytes sent since the connection
3505 This is replaced with the number of IP packets received since the connection
3508 This is replaced with the number of IP packets sent since the connection
3511 This is replaced with the number of IPv6 bytes received since the connection
3513 .It Li IPV6OCTETSOUT
3514 This is replaced with the number of IPv6 bytes sent since the connection
3516 .It Li IPV6PACKETSIN
3517 This is replaced with the number of IPv6 packets received since the connection
3519 .It Li IPV6PACKETSOUT
3520 This is replaced with the number of IPv6 packets sent since the connection
3523 This is replaced with the last label name used.
3524 A label may be specified on the
3526 command line, via the
3534 This is replaced with the IP number assigned to the local interface.
3536 This is replaced with the IPv6 number assigned to the local interface.
3538 This is replaced with the number of bytes received since the connection
3541 This is replaced with the number of bytes sent since the connection
3544 This is replaced with the number of packets received since the connection
3547 This is replaced with the number of packets sent since the connection
3550 This is replaced with the value of the peers endpoint discriminator.
3552 This is replaced with the current process id.
3554 This is replaced with the name of the diagnostic socket.
3556 This is replaced with the bundle uptime in HH:MM:SS format.
3558 This is replaced with the username that has been authenticated with PAP or
3560 Normally, this variable is assigned only in -direct mode.
3561 This value is available irrespective of whether utmp logging is enabled.
3563 This is replaced with the current version number of
3567 These substitutions are also done by the
3574 If you wish to pause
3576 while the command executes, use the
3579 .It clear physical|ipcp|ipv6 Op current|overall|peak...
3580 Clear the specified throughput values at either the
3588 is specified, context must be given (see the
3591 If no second argument is given, all values are cleared.
3592 .It clone Ar name Ns Xo
3593 .Op \&, Ns Ar name Ns
3596 Clone the specified link, creating one or more new links according to the
3599 This command must be used from the
3601 command below unless you've only got a single link (in which case that
3602 link becomes the default).
3603 Links may be removed using the
3607 The default link name is
3609 .It close Op lcp|ccp Ns Op !\&
3610 If no arguments are given, the relevant protocol layers will be brought
3611 down and the link will be closed.
3614 is specified, the LCP layer is brought down, but
3616 will not bring the link offline.
3617 It is subsequently possible to use
3620 to talk to the peer machine if, for example, something like
3625 is specified, only the relevant compression layer is closed.
3628 is used, the compression layer will remain in the closed state, otherwise
3629 it will re-enter the STOPPED state, waiting for the peer to initiate
3630 further CCP negotiation.
3631 In any event, this command does not disconnect the user from
3642 This command deletes the route with the given
3649 all non-direct entries in the routing table for the current interface,
3652 entries are deleted.
3657 the default route is deleted.
3665 will not complain if the route does not already exist.
3671 This command is the equivalent of
3675 and is provided for backwards compatibility.
3676 .It down Op Ar lcp|ccp
3677 Bring the relevant layer down ungracefully, as if the underlying layer
3678 had become unavailable.
3679 It's not considered polite to use this command on
3680 a Finite State Machine that's in the OPEN state.
3682 supplied, the entire link is closed (or if no context is given, all links
3688 layer is terminated but the device is not brought offline and the link
3692 is specified, only the relevant compression layer(s) are terminated.
3693 .It help|? Op Ar command
3694 Show a list of available commands.
3697 is specified, show the usage string for that command.
3698 .It ident Op Ar text Ns No ...
3699 Identify the link to the peer using
3703 is empty, link identification is disabled.
3704 It is possible to use any of the words described for the
3709 command for details of when
3711 identifies itself to the peer.
3712 .It iface Ar command Op args
3713 This command is used to control the interface used by
3716 may be one of the following:
3720 .Ar addr Ns Op / Ns Ar bits
3731 combination to the interface.
3732 Instead of specifying
3736 (with no space between it and
3738 If the given address already exists, the command fails unless the
3740 is used - in which case the previous interface address entry is overwritten
3741 with the new one, allowing a change of netmask or peer address.
3752 .Dq 255.255.255.255 .
3753 This address (the broadcast address) is the only duplicate peer address that
3756 .It iface clear Op INET | INET6
3757 If this command is used while
3759 is in the OPENED state or while in
3761 mode, all addresses except for the NCP negotiated address are deleted
3765 is not in the OPENED state and is not in
3767 mode, all interface addresses are deleted.
3769 If the INET or INET6 arguments are used, only addresses for that address
3771 .It iface delete Ns Xo
3776 This command deletes the given
3781 is used, no error is given if the address isn't currently assigned to
3782 the interface (and no deletion takes place).
3784 Shows the current state and current addresses for the interface.
3785 It is much the same as running
3786 .Dq ifconfig INTERFACE .
3787 .It iface help Op Ar sub-command
3788 This command, when invoked without
3790 will show a list of possible
3792 sub-commands and a brief synopsis for each.
3795 only the synopsis for the given sub-command is shown.
3797 .It Oo Ic data Oc Ns Xo
3799 .Ar name Ns Op , Ns Ar name Ns
3800 .No ... Ar command Op Ar args
3802 This command may prefix any other command if the user wishes to
3803 specify which link the command should affect.
3804 This is only applicable after multiple links have been created in Multi-link
3810 specifies the name of an existing link.
3813 is a comma separated list,
3815 is executed on each link.
3821 is executed on all links.
3822 .It Ic load Oo Ar label Oc Ns Xo
3845 will not attempt to make an immediate connection.
3846 .It log Ar word Ns No ...
3847 Send the given word(s) to the log file with the prefix
3849 Word substitutions are done as explained under the
3852 .It open Op lcp|ccp|ipcp
3853 This is the opposite of the
3856 All closed links are immediately brought up apart from second and subsequent
3858 links - these will come up based on the
3860 command that has been used.
3864 argument is used while the LCP layer is already open, LCP will be
3866 This allows various LCP options to be changed, after which
3868 can be used to put them into effect.
3869 After renegotiating LCP,
3870 any agreed authentication will also take place.
3874 argument is used, the relevant compression layer is opened.
3875 Again, if it is already open, it will be renegotiated.
3879 argument is used, the link will be brought up as normal, but if
3880 IPCP is already open, it will be renegotiated and the network
3881 interface will be reconfigured.
3883 It is probably not good practice to re-open the PPP state machines
3884 like this as it's possible that the peer will not behave correctly.
3887 however useful as a way of forcing the CCP or VJ dictionaries to be reset.
3889 Specify the password required for access to the full
3892 This password is required when connecting to the diagnostic port (see the
3903 logging is active, instead, the literal string
3909 is executed from the controlling connection or from a command file,
3910 ppp will exit after closing all connections.
3911 Otherwise, if the user
3912 is connected to a diagnostic socket, the connection is simply dropped.
3918 will exit despite the source of the command after closing all existing
3921 This command removes the given link.
3922 It is only really useful in multi-link mode.
3923 A link must be in the
3925 state before it is removed.
3926 .It rename|mv Ar name
3927 This command renames the given link to
3931 is already used by another link.
3933 The default link name is
3940 may make the log file more readable.
3941 .It resolv Ar command
3942 This command controls
3949 starts up, it loads the contents of this file into memory and retains this
3950 image for future use.
3952 is one of the following:
3953 .Bl -tag -width readonly
3956 .Pa /etc/resolv.conf
3962 will still attempt to negotiate nameservers with the peer, making the results
3968 This is the opposite of the
3973 .Pa /etc/resolv.conf
3975 This may be necessary if for example a DHCP client overwrote
3976 .Pa /etc/resolv.conf .
3979 .Pa /etc/resolv.conf
3980 with the version originally read at startup or with the last
3983 This is sometimes a useful command to put in the
3984 .Pa /etc/ppp/ppp.linkdown
3988 .Pa /etc/resolv.conf
3990 This command will work even if the
3992 command has been used.
3993 It may be useful as a command in the
3994 .Pa /etc/ppp/ppp.linkup
3995 file if you wish to defer updating
3996 .Pa /etc/resolv.conf
3997 until after other commands have finished.
4002 .Pa /etc/resolv.conf
4007 successfully negotiates a DNS.
4008 This is the opposite of the
4013 This option is not (yet) implemented.
4017 to identify itself to the peer.
4018 The link must be in LCP state or higher.
4019 If no identity has been set (via the
4025 When an identity has been set,
4027 will automatically identify itself when it sends or receives a configure
4028 reject, when negotiation fails or when LCP reaches the opened state.
4030 Received identification packets are logged to the LCP log (see
4032 for details) and are never responded to.
4037 This option allows the setting of any of the following variables:
4039 .It set accmap Ar hex-value
4040 ACCMap stands for Asynchronous Control Character Map.
4042 negotiated with the peer, and defaults to a value of 00000000 in hex.
4043 This protocol is required to defeat hardware that depends on passing
4044 certain characters from end to end (such as XON/XOFF etc).
4046 For the XON/XOFF scenario, use
4047 .Dq set accmap 000a0000 .
4048 .It Ic set Oo Ic auth Oc Ns Xo
4051 This sets the authentication key (or password) used in client mode
4052 PAP or CHAP negotiation to the given value.
4053 It also specifies the
4054 password to be used in the dial or login scripts in place of the
4056 sequence, preventing the actual password from being logged.
4061 logging is in effect,
4065 for security reasons.
4067 If the first character of
4069 is an exclamation mark
4072 treats the remainder of the string as a program that must be executed
4084 it is treated as a single literal
4086 otherwise, ignoring the
4089 is parsed as a program to execute in the same was as the
4091 command above, substituting special names in the same manner.
4094 will feed the program three lines of input, each terminated by a newline
4098 The host name as sent in the CHAP challenge.
4100 The challenge string as sent in the CHAP challenge.
4106 Two lines of output are expected:
4111 to be sent with the CHAP response.
4115 which is encrypted with the challenge and request id, the answer being sent
4116 in the CHAP response packet.
4121 in this manner, it's expected that the host challenge is a series of ASCII
4122 digits or characters.
4123 An encryption device or Secure ID card is usually
4124 required to calculate the secret appropriate for the given challenge.
4125 .It set authname Ar id
4126 This sets the authentication id used in client mode PAP or CHAP negotiation.
4130 mode with CHAP enabled,
4132 is used in the initial authentication challenge and should normally be set to
4133 the local machine name.
4135 .Ar min-percent max-percent period
4137 These settings apply only in multi-link mode and default to zero, zero and
4143 mode link is available, only the first link is made active when
4145 first reads data from the tun device.
4148 link will be opened only when the current bundle throughput is at least
4150 percent of the total bundle bandwidth for
4153 When the current bundle throughput decreases to
4155 percent or less of the total bundle bandwidth for
4159 link will be brought down as long as it's not the last active link.
4161 Bundle throughput is measured as the maximum of inbound and outbound
4164 The default values cause
4166 links to simply come up one at a time.
4168 Certain devices cannot determine their physical bandwidth, so it
4169 is sometimes necessary to use the
4171 command (described below) to make
4174 .It set bandwidth Ar value
4175 This command sets the connection bandwidth in bits per second.
4177 must be greater than zero.
4178 It is currently only used by the
4181 .It set callback Ar option Ns No ...
4182 If no arguments are given, callback is disabled, otherwise,
4186 mode, will accept) one of the given
4187 .Ar option Ns No s .
4188 In client mode, if an
4192 will request a different
4194 until no options remain at which point
4196 will terminate negotiations (unless
4198 is one of the specified
4202 will accept any of the given protocols - but the client
4204 request one of them.
4205 If you wish callback to be optional, you must {include}
4211 are as follows (in this order of preference):
4214 The callee is expected to decide the callback number based on
4218 is the callee, the number should be specified as the fifth field of
4220 .Pa /etc/ppp/ppp.secret .
4222 Microsoft's callback control protocol is used.
4227 If you wish to negotiate
4229 in client mode but also wish to allow the server to request no callback at
4230 CBCP negotiation time, you must specify both
4234 as callback options.
4236 .Ar number Ns Op , Ns Ar number Ns
4239 The caller specifies the
4245 should be either a comma separated list of allowable numbers or a
4247 meaning any number is permitted.
4250 is the caller, only a single number should be specified.
4252 Note, this option is very unsafe when used with a
4254 as a malicious caller can tell
4256 to call any (possibly international) number without first authenticating
4259 If the peer does not wish to do callback at all,
4261 will accept the fact and continue without callback rather than terminating
4263 This is required (in addition to one or more other callback
4264 options) if you wish callback to be optional.
4267 .No *| Ns Ar number Ns Oo
4268 .No , Ns Ar number Ns ...\& Oc
4269 .Op Ar delay Op Ar retry
4271 If no arguments are given, CBCP (Microsoft's CallBack Control Protocol)
4272 is disabled - ie, configuring CBCP in the
4274 command will result in
4276 requesting no callback in the CBCP phase.
4279 attempts to use the given phone
4280 .Ar number Ns No (s).
4285 will insist that the client uses one of these numbers, unless
4287 is used in which case the client is expected to specify the number.
4291 will attempt to use one of the given numbers (whichever it finds to
4292 be agreeable with the peer), or if
4296 will expect the peer to specify the number.
4298 .No off| Ns Ar seconds Ns Op !\&
4302 checks for the existence of carrier depending on the type of device
4303 that has been opened:
4304 .Bl -tag -width XXX -offset XXX
4305 .It Terminal Devices
4306 Carrier is checked one second after the login script is complete.
4309 assumes that this is because the device doesn't support carrier (which
4312 NULL-modem cables), logs the fact and stops checking
4315 As ptys don't support the
4317 ioctl, the tty device will switch all
4318 carrier detection off when it detects that the device is a pty.
4319 .It PPPoE (netgraph) Devices
4320 Carrier is checked once per second for 5 seconds.
4321 If it's not set after
4322 the fifth second, the connection attempt is considered to have failed and
4323 the device is closed.
4324 Carrier is always required for PPPoE devices.
4327 All other device types don't support carrier.
4328 Setting a carrier value will
4329 result in a warning when the device is opened.
4331 Some modems take more than one second after connecting to assert the carrier
4333 If this delay isn't increased, this will result in
4335 inability to detect when the link is dropped, as
4337 assumes that the device isn't asserting carrier.
4341 command overrides the default carrier behaviour.
4343 specifies the maximum number of seconds that
4345 should wait after the dial script has finished before deciding if
4346 carrier is available or not.
4352 will not check for carrier on the device, otherwise
4354 will not proceed to the login script until either carrier is detected
4357 has elapsed, at which point
4359 assumes that the device will not set carrier.
4361 If no arguments are given, carrier settings will go back to their default
4366 is followed immediately by an exclamation mark
4372 If carrier is not detected after
4374 seconds, the link will be disconnected.
4375 .It set choked Op Ar timeout
4376 This sets the number of seconds that
4378 will keep a choked output queue before dropping all pending output packets.
4381 is less than or equal to zero or if
4383 isn't specified, it is set to the default value of
4386 A choked output queue occurs when
4388 has read a certain number of packets from the local network for transmission,
4389 but cannot send the data due to link failure (the peer is busy etc.).
4391 will not read packets indefinitely.
4392 Instead, it reads up to
4398 packets in multi-link mode), then stops reading the network interface
4401 seconds have passed or at least one packet has been sent.
4405 seconds pass, all pending output packets are dropped.
4406 .It set ctsrts|crtscts on|off
4407 This sets hardware flow control.
4408 Hardware flow control is
4411 .It set deflate Ar out-winsize Op Ar in-winsize
4412 This sets the DEFLATE algorithms default outgoing and incoming window
4418 must be values between
4426 will insist that this window size is used and will not accept any other
4427 values from the peer.
4428 .It set dns Op Ar primary Op Ar secondary
4429 This command specifies DNS overrides for the
4434 command description above for details.
4435 This command does not affect the IP numbers requested using
4437 .It set device|line Xo
4440 This sets the device(s) to which
4442 will talk to the given
4445 All serial device names are expected to begin with
4447 and are usually called
4454 it must either begin with an exclamation mark
4457 .No PPPoE: Ns Ar iface Ns Xo
4458 .Op \&: Ns Ar provider Ns
4462 enabled systems), or be of the format
4464 .Ar host : port Op /tcp|udp .
4467 If it begins with an exclamation mark, the rest of the device name is
4468 treated as a program name, and that program is executed when the device
4470 Standard input, output and error are fed back to
4472 and are read and written as if they were a regular device.
4475 .No PPPoE: Ns Ar iface Ns Xo
4476 .Op \&: Ns Ar provider Ns
4478 specification is given,
4480 will attempt to create a
4482 over Ethernet connection using the given
4490 will attempt to load it using
4492 If this fails, an external program must be used such as the
4494 program available under
4498 is passed as the service name in the PPPoE Discovery Initiation (PADI)
4500 If no provider is given, an empty value will be used.
4502 When a PPPoE connection is established,
4504 will place the name of the Access Concentrator in the environment variable
4511 for further details.
4514 .Ar host Ns No : Ns Ar port Ns Oo
4517 specification is given,
4519 will attempt to connect to the given
4527 suffix is not provided, the default is
4529 Refer to the section on
4530 .Em PPP OVER TCP and UDP
4531 above for further details.
4537 will attempt to open each one in turn until it succeeds or runs out of
4539 .It set dial Ar chat-script
4540 This specifies the chat script that will be used to dial the other
4547 and to the example configuration files for details of the chat script
4549 It is possible to specify some special
4551 in your chat script as follows:
4554 When used as the last character in a
4556 string, this indicates that a newline should not be appended.
4558 When the chat script encounters this sequence, it delays two seconds.
4560 When the chat script encounters this sequence, it delays for one quarter of
4563 This is replaced with a newline character.
4565 This is replaced with a carriage return character.
4567 This is replaced with a space character.
4569 This is replaced with a tab character.
4571 This is replaced by the current phone number (see
4575 This is replaced by the current
4581 This is replaced by the current
4588 Note that two parsers will examine these escape sequences, so in order to
4591 see the escape character, it is necessary to escape it from the
4592 .Sq command parser .
4593 This means that in practice you should use two escapes, for example:
4594 .Bd -literal -offset indent
4595 set dial "... ATDT\\\\T CONNECT"
4598 It is also possible to execute external commands from the chat script.
4599 To do this, the first character of the expect or send string is an
4602 If a literal exclamation mark is required, double it up to
4604 and it will be treated as a single literal
4606 When the command is executed, standard input and standard output are
4607 directed to the open device (see the
4609 command), and standard error is read by
4611 and substituted as the expect or send string.
4614 is running in interactive mode, file descriptor 3 is attached to
4617 For example (wrapped for readability):
4618 .Bd -literal -offset indent
4619 set login "TIMEOUT 5 \\"\\" \\"\\" login:--login: ppp \e
4620 word: ppp \\"!sh \\\\-c \\\\\\"echo \\\\-n label: >&2\\\\\\"\\" \e
4621 \\"!/bin/echo in\\" HELLO"
4624 would result in the following chat sequence (output using the
4625 .Sq set log local chat
4626 command before dialing):
4627 .Bd -literal -offset indent
4632 Chat: Expecting: login:--login:
4633 Chat: Wait for (5): login:
4635 Chat: Expecting: word:
4636 Chat: Wait for (5): word:
4638 Chat: Expecting: !sh \\-c "echo \\-n label: >&2"
4639 Chat: Exec: sh -c "echo -n label: >&2"
4640 Chat: Wait for (5): !sh \\-c "echo \\-n label: >&2" --> label:
4641 Chat: Exec: /bin/echo in
4643 Chat: Expecting: HELLO
4644 Chat: Wait for (5): HELLO
4648 Note (again) the use of the escape character, allowing many levels of
4650 Here, there are four parsers at work.
4651 The first parses the original line, reading it as three arguments.
4652 The second parses the third argument, reading it as 11 arguments.
4653 At this point, it is
4656 signs are escaped, otherwise this parser will see them as constituting
4657 an expect-send-expect sequence.
4660 character is seen, the execution parser reads the first command as three
4663 itself expands the argument after the
4665 As we wish to send the output back to the modem, in the first example
4666 we redirect our output to file descriptor 2 (stderr) so that
4668 itself sends and logs it, and in the second example, we just output to stdout,
4669 which is attached directly to the modem.
4671 This, of course means that it is possible to execute an entirely external
4673 command rather than using the internal one.
4676 for a good alternative.
4678 The external command that is executed is subjected to the same special
4679 word expansions as the
4682 .It set enddisc Op label|IP|MAC|magic|psn value
4683 This command sets our local endpoint discriminator.
4684 If set prior to LCP negotiation, and if no
4686 command has been used,
4688 will send the information to the peer using the LCP endpoint discriminator
4690 The following discriminators may be set:
4691 .Bl -tag -width indent
4693 The current label is used.
4695 Our local IP number is used.
4696 As LCP is negotiated prior to IPCP, it is
4697 possible that the IPCP layer will subsequently change this value.
4699 it does, the endpoint discriminator stays at the old value unless manually
4702 This is similar to the
4704 option above, except that the MAC address associated with the local IP
4706 If the local IP number is not resident on any Ethernet
4707 interface, the command will fail.
4709 As the local IP number defaults to whatever the machine host name is,
4711 is usually done prior to any
4715 A 20 digit random number is used.
4716 Care should be taken when using magic numbers as restarting
4718 or creating a link using a different
4720 invocation will also use a different magic number and will therefore not
4721 be recognised by the peer as belonging to the same bundle.
4722 This makes it unsuitable for
4730 should be set to an absolute public switched network number with the
4734 If no arguments are given, the endpoint discriminator is reset.
4735 .It set escape Ar value...
4736 This option is similar to the
4739 It allows the user to specify a set of characters that will be
4741 as they travel across the link.
4742 .It set filter dial|alive|in|out Ar rule-no Xo
4743 .No permit|deny|clear| Ns Ar rule-no
4746 .Ar src_addr Ns Op / Ns Ar width
4747 .Op Ar dst_addr Ns Op / Ns Ar width
4749 .Op src lt|eq|gt Ar port
4750 .Op dst lt|eq|gt Ar port
4754 .Op timeout Ar secs ]
4757 supports four filter sets.
4760 filter specifies packets that keep the connection alive - resetting the
4764 filter specifies packets that cause
4771 filter specifies packets that are allowed to travel
4772 into the machine and the
4774 filter specifies packets that are allowed out of the machine.
4776 Filtering is done prior to any IP alterations that might be done by the
4777 NAT engine on outgoing packets and after any IP alterations that might
4778 be done by the NAT engine on incoming packets.
4779 By default all empty filter sets allow all packets to pass.
4780 Rules are processed in order according to
4782 (unless skipped by specifying a rule number as the
4784 Up to 40 rules may be given for each set.
4785 If a packet doesn't match
4786 any of the rules in a given set, it is discarded.
4791 filters, this means that the packet is dropped.
4794 filters it means that the packet will not reset the idle timer (even if
4796 .Ar in Ns No / Ns Ar out
4799 value) and in the case of
4801 filters it means that the packet will not trigger a dial.
4802 A packet failing to trigger a dial will be dropped rather than queued.
4805 .Sx PACKET FILTERING
4806 above for further details.
4807 .It set hangup Ar chat-script
4808 This specifies the chat script that will be used to reset the device
4809 before it is closed.
4810 It should not normally be necessary, but can
4811 be used for devices that fail to reset themselves properly on close.
4812 .It set help|? Op Ar command
4813 This command gives a summary of available set commands, or if
4815 is specified, the command usage is shown.
4816 .It set ifaddr Oo Ar myaddr Ns
4818 .Oo Ar hisaddr Ns Op / Ns Ar \&nn
4823 This command specifies the IP addresses that will be used during
4825 Addresses are specified using the format
4831 is the preferred IP, but
4833 specifies how many bits of the address we will insist on.
4836 is omitted, it defaults to
4838 unless the IP address is 0.0.0.0 in which case it defaults to
4841 If you wish to assign a dynamic IP number to the peer,
4843 may also be specified as a range of IP numbers in the format
4844 .Bd -ragged -offset indent
4846 .Ar \&IP Oo \&- Ar \&IP Oc Oo ,
4847 .Ar \&IP Oo \&- Ar \&IP Oc Oc ...
4853 .Dl set ifaddr 10.0.0.1 10.0.1.2-10.0.1.10,10.0.1.20
4857 as the local IP number, but may assign any of the given 10 IP
4858 numbers to the peer.
4859 If the peer requests one of these numbers,
4860 and that number is not already in use,
4862 will grant the peers request.
4863 This is useful if the peer wants
4864 to re-establish a link using the same IP number as was previously
4865 allocated (thus maintaining any existing tcp or udp connections).
4867 If the peer requests an IP number that's either outside
4868 of this range or is already in use,
4870 will suggest a random unused IP number from the range.
4874 is specified, it is used in place of
4876 in the initial IPCP negotiation.
4877 However, only an address in the
4879 range will be accepted.
4880 This is useful when negotiating with some
4882 implementations that will not assign an IP number unless their peer
4886 It should be noted that in
4890 will configure the interface immediately upon reading the
4892 line in the config file.
4893 In any other mode, these values are just
4894 used for IPCP negotiations, and the interface isn't configured
4895 until the IPCP layer is up.
4899 argument may be overridden by the third field in the
4901 file once the client has authenticated itself
4905 .Sx AUTHENTICATING INCOMING CONNECTIONS
4906 section for details.
4908 In all cases, if the interface is already configured,
4910 will try to maintain the interface IP numbers so that any existing
4911 bound sockets will remain valid.
4912 .It set ifqueue Ar packets
4913 Set the maximum number of packets that
4915 will read from the tunnel interface while data cannot be sent to any of
4916 the available links.
4917 This queue limit is necessary to flow control outgoing data as the tunnel
4918 interface is likely to be far faster than the combined links available to
4923 is set to a value less than the number of links,
4925 will read up to that value regardless.
4926 This prevents any possible latency problems.
4928 The default value for
4932 .It set ccpretry|ccpretries Oo Ar timeout
4933 .Op Ar reqtries Op Ar trmtries
4935 .It set chapretry|chapretries Oo Ar timeout
4938 .It set ipcpretry|ipcpretries Oo Ar timeout
4939 .Op Ar reqtries Op Ar trmtries
4941 .It set ipv6cpretry|ipv6cpretries Oo Ar timeout
4942 .Op Ar reqtries Op Ar trmtries
4944 .It set lcpretry|lcpretries Oo Ar timeout
4945 .Op Ar reqtries Op Ar trmtries
4947 .It set papretry|papretries Oo Ar timeout
4950 These commands set the number of seconds that
4952 will wait before resending Finite State Machine (FSM) Request packets.
4955 for all FSMs is 3 seconds (which should suffice in most cases).
4959 is specified, it tells
4961 how many configuration request attempts it should make while receiving
4962 no reply from the peer before giving up.
4963 The default is 5 attempts for
4964 CCP, LCP and IPCP and 3 attempts for PAP and CHAP.
4968 is specified, it tells
4970 how many terminate requests should be sent before giving up waiting for the
4972 The default is 3 attempts.
4973 Authentication protocols are
4974 not terminated and it is therefore invalid to specify
4978 In order to avoid negotiations with the peer that will never converge,
4980 will only send at most 3 times the configured number of
4982 in any given negotiation session before giving up and closing that layer.
4988 This command allows the adjustment of the current log level.
4989 Refer to the Logging Facility section for further details.
4990 .It set login Ar chat-script
4993 complements the dial-script.
4994 If both are specified, the login
4995 script will be executed after the dial script.
4996 Escape sequences available in the dial script are also available here.
4997 .It set logout Ar chat-script
4998 This specifies the chat script that will be used to logout
4999 before the hangup script is called.
5000 It should not normally be necessary.
5001 .It set lqrperiod Ar frequency
5002 This command sets the
5009 The default is 30 seconds.
5010 You must also use the
5012 command if you wish to send LQR requests to the peer.
5013 .It set mode Ar interactive|auto|ddial|background
5014 This command allows you to change the
5016 of the specified link.
5017 This is normally only useful in multi-link mode,
5018 but may also be used in uni-link mode.
5020 It is not possible to change a link that is
5025 Note: If you issue the command
5027 and have network address translation enabled, it may be useful to
5028 .Dq enable iface-alias
5032 to do the necessary address translations to enable the process that
5033 triggers the connection to connect once the link is up despite the
5034 peer assigning us a new (dynamic) IP address.
5035 .It set mppe Op 40|56|128|* Op stateless|stateful|*
5036 This option selects the encryption parameters used when negotiation
5038 MPPE can be disabled entirely with the
5041 If no arguments are given,
5043 will attempt to negotiate a stateful link with a 128 bit key, but
5044 will agree to whatever the peer requests (including no encryption
5047 If any arguments are given,
5051 on using MPPE and will close the link if it's rejected by the peer (Note;
5052 this behaviour can be overridden by a configured RADIUS server).
5054 The first argument specifies the number of bits that
5056 should insist on during negotiations and the second specifies whether
5058 should insist on stateful or stateless mode.
5059 In stateless mode, the
5060 encryption dictionary is re-initialised with every packet according to
5061 an encryption key that is changed with every packet.
5063 the encryption dictionary is re-initialised every 256 packets or after
5064 the loss of any data and the key is changed every 256 packets.
5065 Stateless mode is less efficient but is better for unreliable transport
5067 .It set mrru Op Ar value
5068 Setting this option enables Multi-link PPP negotiations, also known as
5069 Multi-link Protocol or MP.
5070 There is no default MRRU (Maximum Reconstructed Receive Unit) value.
5071 If no argument is given, multi-link mode is disabled.
5076 The default MRU (Maximum Receive Unit) is 1500.
5077 If it is increased, the other side *may* increase its MTU.
5078 In theory there is no point in decreasing the MRU to below the default as the
5080 protocol says implementations *must* be able to accept packets of at
5087 will refuse to negotiate a higher value.
5088 The maximum MRU can be set to 2048 at most.
5089 Setting a maximum of less than 1500 violates the
5091 rfc, but may sometimes be necessary.
5094 imposes a maximum of 1492 due to hardware limitations.
5096 If no argument is given, 1500 is assumed.
5097 A value must be given when
5104 The default MTU is 1500.
5105 At negotiation time,
5107 will accept whatever MRU the peer requests (assuming it's
5108 not less than 296 bytes or greater than the assigned maximum).
5111 will not accept MRU values less than
5113 When negotiations are complete, the MTU is used when writing to the
5114 interface, even if the peer requested a higher value MRU.
5115 This can be useful for
5116 limiting your packet size (giving better bandwidth sharing at the expense
5117 of more header data).
5123 will refuse to negotiate a higher value.
5124 The maximum MTU can be set to 2048 at most.
5128 is given, 1500, or whatever the peer asks for is used.
5129 A value must be given when
5132 .It set nbns Op Ar x.x.x.x Op Ar y.y.y.y
5133 This option allows the setting of the Microsoft NetBIOS name server
5134 values to be returned at the peers request.
5135 If no values are given,
5137 will reject any such requests.
5138 .It set openmode active|passive Op Ar delay
5147 will always initiate LCP/IPCP/CCP negotiation one second after the line
5149 If you want to wait for the peer to initiate negotiations, you
5152 If you want to initiate negotiations immediately or after more than one
5153 second, the appropriate
5155 may be specified here in seconds.
5156 .It set parity odd|even|none|mark
5157 This allows the line parity to be set.
5158 The default value is
5160 .It set phone Ar telno Ns Xo
5161 .Oo \&| Ns Ar backupnumber
5162 .Oc Ns ... Ns Oo : Ns Ar nextnumber
5165 This allows the specification of the phone number to be used in
5166 place of the \\\\T string in the dial and login chat scripts.
5167 Multiple phone numbers may be given separated either by a pipe
5172 Numbers after the pipe are only dialed if the dial or login
5173 script for the previous number failed.
5175 Numbers after the colon are tried sequentially, irrespective of
5176 the reason the line was dropped.
5178 If multiple numbers are given,
5180 will dial them according to these rules until a connection is made, retrying
5181 the maximum number of times specified by
5186 mode, each number is attempted at most once.
5187 .It Ic set Oo Ic proc Oc Ns Xo
5188 .Ic title Op Ar value
5190 The current process title as displayed by
5192 is changed according to
5196 is not specified, the original process title is restored.
5198 word replacements done by the shell commands (see the
5200 command above) are done here too.
5202 Note, if USER is required in the process title, the
5204 command must appear in
5206 as it is not known when the commands in
5209 .It set radius Op Ar config-file
5210 This command enables RADIUS support (if it's compiled in).
5212 refers to the radius client configuration file as described in
5214 If PAP, CHAP, MSCHAP or MSCHAPv2 are
5215 .Dq enable Ns No d ,
5218 .Em \&N Ns No etwork
5221 and uses the configured RADIUS server to authenticate rather than
5222 authenticating from the
5224 file or from the passwd database.
5226 If none of PAP, CHAP, MSCHAP or MSCHAPv2 are enabled,
5231 uses the following attributes from the RADIUS reply:
5232 .Bl -tag -width XXX -offset XXX
5233 .It RAD_FRAMED_IP_ADDRESS
5234 The peer IP address is set to the given value.
5235 .It RAD_FRAMED_IP_NETMASK
5236 The tun interface netmask is set to the given value.
5238 If the given MTU is less than the peers MRU as agreed during LCP
5239 negotiation, *and* it is less that any configured MTU (see the
5241 command), the tun interface MTU is set to the given value.
5242 .It RAD_FRAMED_COMPRESSION
5243 If the received compression type is
5246 will request VJ compression during IPCP negotiations despite any
5248 configuration command.
5250 If this attribute is supplied,
5252 will attempt to use it as an additional label to load from the
5257 The load will be attempted before (and in addition to) the normal
5259 If the label doesn't exist, no action is taken and
5261 proceeds to the normal load using the current label.
5262 .It RAD_FRAMED_ROUTE
5263 The received string is expected to be in the format
5264 .Ar dest Ns Op / Ns Ar bits
5267 Any specified metrics are ignored.
5271 are understood as valid values for
5278 to specify the default route, and
5280 is understood to be the same as
5289 For example, a returned value of
5290 .Dq 1.2.3.4/24 0.0.0.0 1 2 -1 3 400
5291 would result in a routing table entry to the 1.2.3.0/24 network via
5293 and a returned value of
5297 would result in a default route to
5300 All RADIUS routes are applied after any sticky routes are applied, making
5301 RADIUS routes override configured routes.
5302 This also applies for RADIUS routes that don't {include} the
5307 .It RAD_SESSION_TIMEOUT
5308 If supplied, the client connection is closed after the given number of
5310 .It RAD_REPLY_MESSAGE
5311 If supplied, this message is passed back to the peer as the authentication
5313 .It RAD_MICROSOFT_MS_CHAP_ERROR
5315 .Dv RAD_VENDOR_MICROSOFT
5316 vendor specific attribute is supplied, it is passed back to the peer as the
5317 authentication FAILURE text.
5318 .It RAD_MICROSOFT_MS_CHAP2_SUCCESS
5320 .Dv RAD_VENDOR_MICROSOFT
5321 vendor specific attribute is supplied and if MS-CHAPv2 authentication is
5322 being used, it is passed back to the peer as the authentication SUCCESS text.
5323 .It RAD_MICROSOFT_MS_MPPE_ENCRYPTION_POLICY
5325 .Dv RAD_VENDOR_MICROSOFT
5326 vendor specific attribute is supplied and has a value of 2 (Required),
5328 will insist that MPPE encryption is used (even if no
5330 configuration command has been given with arguments).
5331 If it is supplied with a value of 1 (Allowed), encryption is made optional
5334 configuration commands with arguments).
5335 .It RAD_MICROSOFT_MS_MPPE_ENCRYPTION_TYPES
5337 .Dv RAD_VENDOR_MICROSOFT
5338 vendor specific attribute is supplied, bits 1 and 2 are examined.
5339 If either or both are set, 40 bit and/or 128 bit (respectively) encryption
5340 options are set, overriding any given first argument to the
5343 Note, it is not currently possible for the RADIUS server to specify 56 bit
5345 .It RAD_MICROSOFT_MS_MPPE_RECV_KEY
5347 .Dv RAD_VENDOR_MICROSOFT
5348 vendor specific attribute is supplied, it's value is used as the master
5349 key for decryption of incoming data. When clients are authenticated using
5350 MSCHAPv2, the RADIUS server MUST provide this attribute if inbound MPPE is
5352 .It RAD_MICROSOFT_MS_MPPE_SEND_KEY
5354 .Dv RAD_VENDOR_MICROSOFT
5355 vendor specific attribute is supplied, it's value is used as the master
5356 key for encryption of outgoing data. When clients are authenticated using
5357 MSCHAPv2, the RADIUS server MUST provide this attribute if outbound MPPE is
5361 Values received from the RADIUS server may be viewed using
5363 .It set reconnect Ar timeout ntries
5364 Should the line drop unexpectedly (due to loss of CD or LQR
5365 failure), a connection will be re-established after the given
5367 The line will be re-connected at most
5376 will result in a variable pause, somewhere between 1 and 30 seconds.
5377 .It set recvpipe Op Ar value
5378 This sets the routing table RECVPIPE value.
5379 The optimum value is just over twice the MTU value.
5382 is unspecified or zero, the default kernel controlled value is used.
5383 .It set redial Ar secs Ns Xo
5386 .Oc Ns Op . Ns Ar next
5390 can be instructed to attempt to redial
5393 If more than one phone number is specified (see
5397 is taken before dialing each number.
5400 is taken before starting at the first number again.
5403 may be used here in place of
5407 causing a random delay of between 1 and 30 seconds.
5411 is specified, its value is added onto
5417 will only be incremented at most
5425 delay will be effective, even after
5427 has been exceeded, so an immediate manual dial may appear to have
5429 If an immediate dial is required, a
5431 should immediately follow the
5436 description above for further details.
5437 .It set sendpipe Op Ar value
5438 This sets the routing table SENDPIPE value.
5439 The optimum value is just over twice the MTU value.
5442 is unspecified or zero, the default kernel controlled value is used.
5443 .It "set server|socket" Ar TcpPort Ns No \&| Ns Xo
5444 .Ar LocalName Ns No |none|open|closed
5445 .Op password Op Ar mask
5449 to listen on the given socket or
5451 for incoming command connections.
5457 to close any existing socket and clear the socket configuration.
5462 to attempt to re-open the port.
5467 to close the open port.
5469 If you wish to specify a local domain socket,
5471 must be specified as an absolute file name, otherwise it is assumed
5472 to be the name or number of a TCP port.
5473 You may specify the octal umask to be used with a local domain socket.
5479 for details of how to translate TCP port names.
5481 You must also specify the password that must be entered by the client
5484 variable above) when connecting to this socket.
5486 specified as an empty string, no password is required for connecting clients.
5488 When specifying a local domain socket, the first
5490 sequence found in the socket name will be replaced with the current
5491 interface unit number.
5492 This is useful when you wish to use the same
5493 profile for more than one connection.
5495 In a similar manner TCP sockets may be prefixed with the
5497 character, in which case the current interface unit number is added to
5502 with a server socket, the
5504 command is the preferred mechanism of communications.
5507 can also be used, but link encryption may be implemented in the future, so
5515 interact with the diagnostic socket.
5516 .It set speed Ar value
5517 This sets the speed of the serial device.
5518 If speed is specified as
5521 treats the device as a synchronous device.
5523 Certain device types will know whether they should be specified as
5524 synchronous or asynchronous.
5525 These devices will override incorrect
5526 settings and log a warning to this effect.
5527 .It set stopped Op Ar LCPseconds Op Ar CCPseconds
5528 If this option is set,
5530 will time out after the given FSM (Finite State Machine) has been in
5531 the stopped state for the given number of
5533 This option may be useful if the peer sends a terminate request,
5534 but never actually closes the connection despite our sending a terminate
5536 This is also useful if you wish to
5537 .Dq set openmode passive
5538 and time out if the peer doesn't send a Configure Request within the
5541 .Dq set log +lcp +ccp
5544 log the appropriate state transitions.
5546 The default value is zero, where
5548 doesn't time out in the stopped state.
5550 This value should not be set to less than the openmode delay (see
5553 .It set timeout Ar idleseconds Op Ar mintimeout
5554 This command allows the setting of the idle timer.
5555 Refer to the section titled
5556 .Sx SETTING THE IDLE TIMER
5557 for further details.
5563 will never idle out before the link has been up for at least that number
5571 This command controls the ports that
5573 prioritizes when transmitting data.
5574 The default priority TCP ports
5575 are ports 21 (ftp control), 22 (ssh), 23 (telnet), 513 (login), 514 (shell),
5576 543 (klogin) and 544 (kshell).
5577 There are no priority UDP ports by default.
5592 are given, the priority port lists are cleared (although if
5596 is specified, only that list is cleared).
5599 argument is prefixed with a plus
5603 the current list is adjusted, otherwise the list is reassigned.
5605 prefixed with a plus or not prefixed at all are added to the list and
5607 prefixed with a minus are removed from the list.
5611 is specified, all priority port lists are disabled and even
5613 packets are not prioritised.
5614 .It set vj slotcomp on|off
5617 whether it should attempt to negotiate VJ slot compression.
5618 By default, slot compression is turned
5620 .It set vj slots Ar nslots
5621 This command sets the initial number of slots that
5623 will try to negotiate with the peer when VJ compression is enabled (see the
5626 It defaults to a value of 16.
5634 .It shell|! Op Ar command
5637 is not specified a shell is invoked according to the
5639 environment variable.
5640 Otherwise, the given
5643 Word replacement is done in the same way as for the
5645 command as described above.
5647 Use of the ! character
5648 requires a following space as with any of the other commands.
5649 You should note that this command is executed in the foreground;
5651 will not continue running until this process has exited.
5654 command if you wish processing to happen in the background.
5656 This command allows the user to examine the following:
5659 Show the current bundle settings.
5661 Show the current CCP compression statistics.
5663 Show the current VJ compression statistics.
5665 Show the current escape characters.
5666 .It show filter Op Ar name
5667 List the current rules for the given filter.
5670 is not specified, all filters are shown.
5672 Show the current HDLC statistics.
5674 Give a summary of available show commands.
5676 Show the current interface information
5680 Show the current IPCP statistics.
5682 Show the protocol layers currently in use.
5684 Show the current LCP statistics.
5685 .It Ic show Oo Ic data Oc Ns Xo
5688 Show high level link information.
5690 Show a list of available logical links.
5692 Show the current log values.
5694 Show current memory statistics.
5696 Show the current NCP statistics.
5698 Show low level link information.
5700 Show Multi-link information.
5702 Show current protocol totals.
5704 Show the current routing tables.
5706 Show the current stopped timeouts.
5708 Show the active alarm timers.
5710 Show the current version number of
5714 Go into terminal mode.
5715 Characters typed at the keyboard are sent to the device.
5716 Characters read from the device are displayed on the screen.
5721 automatically enables Packet Mode and goes back into command mode.
5726 Read the example configuration files.
5727 They are a good source of information.
5736 to get online information about what's available.
5738 The following URLs contain useful information:
5739 .Bl -bullet -compact
5741 .Pa http://www.dragonflybsd.org/docs/handbook/handbook-userppp/
5746 refers to four files:
5752 These files are placed in the
5756 .It Pa /etc/ppp/ppp.conf
5757 System default configuration file.
5758 .It Pa /etc/ppp/ppp.secret
5759 An authorisation file for each system.
5760 .It Pa /etc/ppp/ppp.linkup
5761 A file to check when
5763 establishes a network level connection.
5764 .It Pa /etc/ppp/ppp.linkdown
5765 A file to check when
5767 closes a network level connection.
5768 .It Pa /var/log/ppp.log
5769 Logging and debugging information file.
5770 Note, this name is specified in
5771 .Pa /etc/syslog.conf .
5774 for further details.
5775 .It Pa /var/spool/lock/LCK..*
5776 tty port locking file.
5779 for further details.
5780 .It Pa /var/run/tunN.pid
5781 The process id (pid) of the
5783 program connected to the tunN device, where
5785 is the number of the device.
5786 .It Pa /var/run/ttyXX.if
5787 The tun interface used by this port.
5788 Again, this file is only created in
5794 .It Pa /etc/services
5795 Get port number if port number is using service name.
5796 .It Pa /var/run/ppp-authname-class-value
5797 In multi-link mode, local domain sockets are created using the peer
5800 the peer endpoint discriminator class
5802 and the peer endpoint discriminator value
5804 As the endpoint discriminator value may be a binary value, it is turned
5805 to HEX to determine the actual file name.
5807 This socket is used to pass links between different instances of
5819 ifdef({LOCALNAT},{},{.Xr libalias 3 ,
5821 ifdef({LOCALRAD},{},{.Xr libradius 3 ,
5850 This program was originally written by
5851 .An Toshiharu OHNO Aq Mt tony-o@iij.ad.jp ,
5852 and was submitted to
5855 .An Atsushi Murai Aq Mt amurai@spec.co.jp .
5857 It was substantially modified during 1997 by
5858 .An Brian Somers Aq Mt brian@Awfulhak.org ,
5861 in November that year
5862 (just after the 2.2 release).
5864 Most of the code was rewritten by
5866 in early 1998 when multi-link ppp support was added.
tuxillo's projects / dragonfly.git / blob