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
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21 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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28 .\" $FreeBSD: src/usr.sbin/ppp/ppp.8.m4,v 1.301.2.1 2002/09/01 02:12:31 brian Exp $
29 .\" $DragonFly: src/usr.sbin/ppp/ppp.8.m4,v 1.12 2008/05/02 02:05:08 swildner Exp $
31 .Dd September 20, 1995
36 .Nd Point to Point Protocol (a.k.a. user-ppp)
45 This is a user process
50 is implemented as a part of the kernel (e.g., as managed by
52 and it's thus somewhat hard to debug and/or modify its behaviour.
53 However, in this implementation
55 is done as a user process with the help of the
56 tunnel device driver (tun).
60 flag does the equivalent of a
64 network address translation features.
67 to act as a NAT or masquerading engine for all machines on an internal
69 ifdef({LOCALNAT},{},{Refer to
71 for details on the technical side of the NAT engine.
74 .Sx NETWORK ADDRESS TRANSLATION (PACKET ALIASING)
75 section of this manual page for details on how to configure NAT in
82 to be silent at startup rather than displaying the mode and interface
89 to only attempt to open
90 .Pa /dev/tun Ns Ar N .
93 will start with a value of 0 for
95 and keep trying to open a tunnel device by incrementing the value of
97 by one each time until it succeeds.
98 If it fails three times in a row
99 because the device file is missing, it gives up.
105 .Bl -tag -width XXX -offset XXX
108 opens the tun interface, configures it then goes into the background.
109 The link isn't brought up until outgoing data is detected on the tun
110 interface at which point
112 attempts to bring up the link.
113 Packets received (including the first one) while
115 is trying to bring the link up will remain queued for a default of
125 must be given on the command line (see below) and a
127 must be done in the system profile that specifies a peer IP address to
128 use when configuring the interface.
131 is usually appropriate.
135 .Pa /usr/share/examples/ppp/ppp.conf.sample
140 attempts to establish a connection with the peer immediately.
143 goes into the background and the parent process returns an exit code
147 exits with a non-zero result.
151 attempts to establish a connection with the peer immediately, but never
153 The link is created in background mode.
154 This is useful if you wish to control
156 invocation from another process.
158 This is used for receiving incoming connections.
162 line and uses descriptor 0 as the link.
164 If callback is configured,
168 information when dialing back.
170 This option is designed for machines connected with a dedicated
173 will always keep the device open and will never use any configured
176 This mode is equivalent to
180 will bring the link back up any time it's dropped for any reason.
182 This is a no-op, and gives the same behaviour as if none of the above
183 modes have been specified.
185 loads any sections specified on the command line then provides an
189 One or more configuration entries or systems
191 .Pa /etc/ppp/ppp.conf )
192 may also be specified on the command line.
197 .Pa /etc/ppp/ppp.conf
198 at startup, followed by each of the systems specified on the command line.
201 .It Provides an interactive user interface.
202 Using its command mode, the user can
203 easily enter commands to establish the connection with the remote end, check
204 the status of connection and close the connection.
205 All functions can also be optionally password protected for security.
206 .It Supports both manual and automatic dialing.
207 Interactive mode has a
209 command which enables you to talk to the device directly.
210 When you are connected to the remote peer and it starts to talk
213 detects it and switches to packet mode automatically.
215 determined the proper sequence for connecting with the remote host, you
216 can write a chat script to {define} the necessary dialing and login
217 procedure for later convenience.
218 .It Supports on-demand dialup capability.
223 will act as a daemon and wait for a packet to be sent over the
226 When this happens, the daemon automatically dials and establishes the
228 In almost the same manner
230 mode (direct-dial mode) also automatically dials and establishes the
232 However, it differs in that it will dial the remote site
233 any time it detects the link is down, even if there are no packets to be
235 This mode is useful for full-time connections where we worry less
236 about line charges and more about being connected full time.
239 mode is also available.
240 This mode is targeted at a dedicated link between two machines.
242 will never voluntarily quit from dedicated mode - you must send it the
244 command via its diagnostic socket.
247 will force an LCP renegotiation, and a
249 will force it to exit.
250 .It Supports client callback.
252 can use either the standard LCP callback protocol or the Microsoft
253 CallBack Control Protocol
254 .Pa ( ftp://ftp.microsoft.com/developr/rfc/cbcp.txt ) .
255 .It Supports NAT or packet aliasing.
256 Packet aliasing (a.k.a. IP masquerading) allows computers on a
257 private, unregistered network to access the Internet.
260 host acts as a masquerading gateway.
261 IP addresses as well as TCP and
262 UDP port numbers are NAT'd for outgoing packets and de-NAT'd for
264 .It Supports background PPP connections.
265 In background mode, if
267 successfully establishes the connection, it will become a daemon.
268 Otherwise, it will exit with an error.
269 This allows the setup of
270 scripts that wish to execute certain commands only if the connection
271 is successfully established.
272 .It Supports server-side PPP connections.
275 acts as server which accepts incoming
277 connections on stdin/stdout.
278 .It "Supports PAP and CHAP (rfc 1994, 2433 and 2759) authentication.
279 With PAP or CHAP, it is possible to skip the Unix style
281 procedure, and use the
283 protocol for authentication instead.
284 If the peer requests Microsoft CHAP authentication and
286 is compiled with DES support, an appropriate MD4/DES response will be
288 .It Supports RADIUS (rfc 2138 & 2548) authentication.
289 An extension to PAP and CHAP,
296 allows authentication information to be stored in a central or
297 distributed database along with various per-user framed connection
299 ifdef({LOCALRAD},{},{If
301 is available at compile time,
305 requests when configured to do so.
307 .It Supports Proxy Arp.
309 can be configured to make one or more proxy arp entries on behalf of
311 This allows routing from the peer to the LAN without
312 configuring each machine on that LAN.
313 .It Supports packet filtering.
314 User can {define} four kinds of filters: the
316 filter for incoming packets, the
318 filter for outgoing packets, the
320 filter to {define} a dialing trigger packet and the
322 filter for keeping a connection alive with the trigger packet.
323 .It Tunnel driver supports bpf.
326 to check the packet flow over the
329 .It Supports PPP over TCP and PPP over UDP.
330 If a device name is specified as
331 .Em host Ns No : Ns Em port Ns
336 will open a TCP or UDP connection for transporting data rather than using a
337 conventional serial device.
338 UDP connections force
340 into synchronous mode.
341 .It Supports PPP over ISDN.
344 is given a raw B-channel i4b device to open as a link, it's able to talk
347 daemon to establish an ISDN connection.
348 .It Supports PPP over Ethernet (rfc 2516).
351 is given a device specification of the format
352 .No PPPoE: Ns Ar iface Ns Xo
353 .Op \&: Ns Ar provider Ns
367 On systems that do not support
369 an external program such as
372 .It "Supports IETF draft Predictor-1 (rfc 1978) and DEFLATE (rfc 1979) compression."
374 supports not only VJ-compression but also Predictor-1 and DEFLATE compression.
375 Normally, a modem has built-in compression (e.g., v42.bis) and the system
376 may receive higher data rates from it as a result of such compression.
377 While this is generally a good thing in most other situations, this
378 higher speed data imposes a penalty on the system by increasing the
379 number of serial interrupts the system has to process in talking to the
380 modem and also increases latency.
381 Unlike VJ-compression, Predictor-1 and DEFLATE compression pre-compresses
383 network traffic flowing through the link, thus reducing overheads to a
385 .It Supports Microsoft's IPCP extensions (rfc 1877).
386 Name Server Addresses and NetBIOS Name Server Addresses can be negotiated
387 with clients using the Microsoft
389 stack (i.e., Win95, WinNT)
390 .It Supports Multi-link PPP (rfc 1990)
391 It is possible to configure
393 to open more than one physical connection to the peer, combining the
394 bandwidth of all links for better throughput.
395 .It Supports MPPE (draft-ietf-pppext-mppe)
396 MPPE is Microsoft Point to Point Encryption scheme.
397 It is possible to configure
399 to participate in Microsoft's Windows VPN.
402 can only get encryption keys from CHAP 81 authentication.
404 must be compiled with DES for MPPE to operate.
405 .It Supports IPV6CP (rfc 2023).
406 An IPv6 connection can be made in addition to or instead of the normal
419 will not run if the invoking user id is not zero.
420 This may be overridden by using the
423 .Pa /etc/ppp/ppp.conf .
424 When running as a normal user,
426 switches to user id 0 in order to alter the system routing table, set up
427 system lock files and read the ppp configuration files.
428 All external commands (executed via the "shell" or "!bg" commands) are executed
429 as the user id that invoked
433 logging facility if you're interested in what exactly is done as user id
438 you may need to deal with some initial configuration details.
441 Your kernel must {include} a tunnel device (the GENERIC kernel includes
443 If it doesn't, or if you require more than one tun
444 interface, you'll need to rebuild your kernel with the following line in
445 your kernel configuration file:
447 .Dl pseudo-device tun N
451 is the maximum number of
453 connections you wish to support.
457 directory for the tunnel device entries
461 represents the number of the tun device, starting at zero.
462 If they don't exist, you can create them by running "sh ./MAKEDEV tunN".
463 This will create tun devices 0 through
466 Make sure that your system has a group named
470 file and that the group contains the names of all users expected to use
474 manual page for details.
475 Each of these users must also be given access using the
478 .Pa /etc/ppp/ppp.conf .
485 A common log file name is
486 .Pa /var/log/ppp.log .
487 To make output go to this file, put the following lines in the
490 .Bd -literal -offset indent
492 *.*<TAB>/var/log/ppp.log
495 It is possible to have more than one
497 log file by creating a link to the
505 .Bd -literal -offset indent
507 *.*<TAB>/var/log/ppp0.log
511 .Pa /etc/syslog.conf .
512 Don't forget to send a
517 .Pa /etc/syslog.conf .
519 Although not strictly relevant to
521 operation, you should configure your resolver so that it works correctly.
522 This can be done by configuring a local DNS
525 or by adding the correct
528 .Pa /etc/resolv.conf .
531 manual page for details.
533 Alternatively, if the peer supports it,
535 can be configured to ask the peer for the nameserver address(es) and to
543 commands below for details.
546 In the following examples, we assume that your machine name is
552 above) with no arguments, you are presented with a prompt:
553 .Bd -literal -offset indent
559 part of your prompt should always be in upper case.
560 If it is in lower case, it means that you must supply a password using the
563 This only ever happens if you connect to a running version of
565 and have not authenticated yourself using the correct password.
567 You can start by specifying the device name and speed:
568 .Bd -literal -offset indent
569 ppp ON awfulhak> set device /dev/cuaa0
570 ppp ON awfulhak> set speed 38400
573 Normally, hardware flow control (CTS/RTS) is used.
575 certain circumstances (as may happen when you are connected directly
576 to certain PPP-capable terminal servers), this may result in
578 hanging as soon as it tries to write data to your communications link
579 as it is waiting for the CTS (clear to send) signal - which will never
581 Thus, if you have a direct line and can't seem to make a
582 connection, try turning CTS/RTS off with
584 If you need to do this, check the
586 description below too - you'll probably need to
587 .Dq set accmap 000a0000 .
589 Usually, parity is set to
594 Parity is a rather archaic error checking mechanism that is no
595 longer used because modern modems do their own error checking, and most
596 link-layer protocols (that's what
598 is) use much more reliable checking mechanisms.
599 Parity has a relatively
600 huge overhead (a 12.5% increase in traffic) and as a result, it is always
607 However, some ISPs (Internet Service Providers) may use
608 specific parity settings at connection time (before
611 Notably, Compuserve insist on even parity when logging in:
612 .Bd -literal -offset indent
613 ppp ON awfulhak> set parity even
616 You can now see what your current device settings look like:
617 .Bd -literal -offset indent
618 ppp ON awfulhak> show physical
622 Link Type: interactive
628 Device List: /dev/cuaa0
629 Characteristics: 38400bps, cs8, even parity, CTS/RTS on
632 0 octets in, 0 octets out
637 The term command can now be used to talk directly to the device:
638 .Bd -literal -offset indent
639 ppp ON awfulhak> term
645 Password: myisppassword
649 When the peer starts to talk in
652 detects this automatically and returns to command mode.
653 .Bd -literal -offset indent
654 ppp ON awfulhak> # No link has been established
655 Ppp ON awfulhak> # We've connected & finished LCP
656 PPp ON awfulhak> # We've authenticated
657 PPP ON awfulhak> # We've agreed IP numbers
660 If it does not, it's probable that the peer is waiting for your end to
666 configuration packets to the peer, use the
668 command to drop out of terminal mode and enter packet mode.
670 If you never even receive a login prompt, it is quite likely that the
671 peer wants to use PAP or CHAP authentication instead of using Unix-style
672 login/password authentication.
673 To set things up properly, drop back to
674 the prompt and set your authentication name and key, then reconnect:
675 .Bd -literal -offset indent
677 ppp ON awfulhak> set authname myispusername
678 ppp ON awfulhak> set authkey myisppassword
679 ppp ON awfulhak> term
686 You may need to tell ppp to initiate negotiations with the peer here too:
687 .Bd -literal -offset indent
689 ppp ON awfulhak> # No link has been established
690 Ppp ON awfulhak> # We've connected & finished LCP
691 PPp ON awfulhak> # We've authenticated
692 PPP ON awfulhak> # We've agreed IP numbers
695 You are now connected!
698 in the prompt has changed to capital letters to indicate that you have
700 If only some of the three Ps go uppercase, wait until
701 either everything is uppercase or lowercase.
702 If they revert to lowercase, it means that
704 couldn't successfully negotiate with the peer.
705 A good first step for troubleshooting at this point would be to
706 .Bd -literal -offset indent
707 ppp ON awfulhak> set log local phase lcp ipcp
713 command description below for further details.
714 If things fail at this point,
715 it is quite important that you turn logging on and try again.
717 important that you note any prompt changes and report them to anyone trying
720 When the link is established, the show command can be used to see how
722 .Bd -literal -offset indent
723 PPP ON awfulhak> show physical
724 * Modem related information is shown here *
725 PPP ON awfulhak> show ccp
726 * CCP (compression) related information is shown here *
727 PPP ON awfulhak> show lcp
728 * LCP (line control) related information is shown here *
729 PPP ON awfulhak> show ipcp
730 * IPCP (IP) related information is shown here *
731 PPP ON awfulhak> show ipv6cp
732 * IPV6CP (IPv6) related information is shown here *
733 PPP ON awfulhak> show link
734 * Link (high level) related information is shown here *
735 PPP ON awfulhak> show bundle
736 * Logical (high level) connection related information is shown here *
739 At this point, your machine has a host route to the peer.
741 that you can only make a connection with the host on the other side
743 If you want to add a default route entry (telling your
744 machine to send all packets without another routing entry to the other
747 link), enter the following command:
748 .Bd -literal -offset indent
749 PPP ON awfulhak> add default HISADDR
754 represents the IP address of the connected peer.
757 command fails due to an existing route, you can overwrite the existing
759 .Bd -literal -offset indent
760 PPP ON awfulhak> add! default HISADDR
763 This command can also be executed before actually making the connection.
764 If a new IP address is negotiated at connection time,
766 will update your default route accordingly.
768 You can now use your network applications (ping, telnet, ftp etc.)
769 in other windows or terminals on your machine.
770 If you wish to reuse the current terminal, you can put
772 into the background using your standard shell suspend and background
780 section for details on all available commands.
781 .Sh AUTOMATIC DIALING
782 To use automatic dialing, you must prepare some Dial and Login chat scripts.
783 See the example definitions in
784 .Pa /usr/share/examples/ppp/ppp.conf.sample
786 .Pa /etc/ppp/ppp.conf
788 Each line contains one comment, inclusion, label or command:
791 A line starting with a
793 character is treated as a comment line.
794 Leading whitespace are ignored when identifying comment lines.
796 An inclusion is a line beginning with the word
798 It must have one argument - the file to {include}.
800 .Dq {!include} ~/.ppp.conf
801 for compatibility with older versions of
804 A label name starts in the first column and is followed by
808 A command line must contain a space or tab in the first column.
812 .Pa /etc/ppp/ppp.conf
813 file should consist of at least a
816 This section is always executed.
817 It should also contain
818 one or more sections, named according to their purpose, for example,
820 would represent your ISP, and
822 would represent an incoming
825 You can now specify the destination label name when you invoke
827 Commands associated with the
829 label are executed, followed by those associated with the destination
833 is started with no arguments, the
835 section is still executed.
836 The load command can be used to manually load a section from the
837 .Pa /etc/ppp/ppp.conf
839 .Bd -literal -offset indent
840 ppp ON awfulhak> load MyISP
843 Note, no action is taken by
845 after a section is loaded, whether it's the result of passing a label on
846 the command line or using the
849 Only the commands specified for that label in the configuration
851 However, when invoking
858 switches, the link mode tells
860 to establish a connection.
863 command below for further details.
865 Once the connection is made, the
867 portion of the prompt will change to
869 .Bd -literal -offset indent
872 ppp ON awfulhak> dial
878 The Ppp prompt indicates that
880 has entered the authentication phase.
881 The PPp prompt indicates that
883 has entered the network phase.
884 The PPP prompt indicates that
886 has successfully negotiated a network layer protocol and is in
890 .Pa /etc/ppp/ppp.linkup
891 file is available, its contents are executed
894 connection is established.
898 .Pa /usr/share/examples/ppp/ppp.conf.sample
899 which runs a script in the background after the connection is established
904 commands below for a description of possible substitution strings).
905 Similarly, when a connection is closed, the contents of the
906 .Pa /etc/ppp/ppp.linkdown
908 Both of these files have the same format as
909 .Pa /etc/ppp/ppp.conf .
911 In previous versions of
913 it was necessary to re-add routes such as the default route in the
919 where all routes that contain the
925 literals will automatically be updated when the values of these variables
927 .Sh BACKGROUND DIALING
928 If you want to establish a connection using
930 non-interactively (such as from a
934 job) you should use the
941 attempts to establish the connection immediately.
943 numbers are specified, each phone number will be tried once.
944 If the attempt fails,
946 exits immediately with a non-zero exit code.
949 becomes a daemon, and returns an exit status of zero to its caller.
950 The daemon exits automatically if the connection is dropped by the
951 remote system, or it receives a
955 Demand dialing is enabled with the
960 You must also specify the destination label in
961 .Pa /etc/ppp/ppp.conf
965 command to {define} the remote peers IP address.
967 .Pa /usr/share/examples/ppp/ppp.conf.sample )
968 .Bd -literal -offset indent
978 runs as a daemon but you can still configure or examine its
979 configuration by using the
982 .Pa /etc/ppp/ppp.conf ,
984 .Dq Li "set server +3000 mypasswd" )
985 and connecting to the diagnostic port as follows:
986 .Bd -literal -offset indent
987 # pppctl 3000 (assuming tun0)
989 PPP ON awfulhak> show who
990 tcp (127.0.0.1:1028) *
995 command lists users that are currently connected to
998 If the diagnostic socket is closed or changed to a different
999 socket, all connections are immediately dropped.
1003 mode, when an outgoing packet is detected,
1005 will perform the dialing action (chat script) and try to connect
1009 mode, the dialing action is performed any time the line is found
1011 If the connect fails, the default behaviour is to wait 30 seconds
1012 and then attempt to connect when another outgoing packet is detected.
1013 This behaviour can be changed using the
1017 .No set redial Ar secs Ns Xo
1020 .Oc Ns Op . Ns Ar next
1024 .Bl -tag -width attempts -compact
1026 is the number of seconds to wait before attempting
1028 If the argument is the literal string
1030 the delay period is a random value between 1 and 30 seconds inclusive.
1032 is the number of seconds that
1034 should be incremented each time a new dial attempt is made.
1035 The timeout reverts to
1037 only after a successful connection is established.
1038 The default value for
1042 is the maximum number of times
1046 The default value for
1050 is the number of seconds to wait before attempting
1051 to dial the next number in a list of numbers (see the
1054 The default is 3 seconds.
1055 Again, if the argument is the literal string
1057 the delay period is a random value between 1 and 30 seconds.
1059 is the maximum number of times to try to connect for each outgoing packet
1060 that triggers a dial.
1061 The previous value is unchanged if this parameter is omitted.
1062 If a value of zero is specified for
1065 will keep trying until a connection is made.
1069 .Bd -literal -offset indent
1073 will attempt to connect 4 times for each outgoing packet that causes
1074 a dial attempt with a 3 second delay between each number and a 10 second
1075 delay after all numbers have been tried.
1076 If multiple phone numbers
1077 are specified, the total number of attempts is still 4 (it does not
1078 attempt each number 4 times).
1081 .Bd -literal -offset indent
1082 set redial 10+10-5.3 20
1087 to attempt to connect 20 times.
1088 After the first attempt,
1090 pauses for 10 seconds.
1091 After the next attempt it pauses for 20 seconds
1092 and so on until after the sixth attempt it pauses for 1 minute.
1093 The next 14 pauses will also have a duration of one minute.
1096 connects, disconnects and fails to connect again, the timeout starts again
1099 Modifying the dial delay is very useful when running
1103 mode on both ends of the link.
1104 If each end has the same timeout,
1105 both ends wind up calling each other at the same time if the link
1106 drops and both ends have packets queued.
1107 At some locations, the serial link may not be reliable, and carrier
1108 may be lost at inappropriate times.
1109 It is possible to have
1111 redial should carrier be unexpectedly lost during a session.
1112 .Bd -literal -offset indent
1113 set reconnect timeout ntries
1118 to re-establish the connection
1120 times on loss of carrier with a pause of
1122 seconds before each try.
1124 .Bd -literal -offset indent
1130 that on an unexpected loss of carrier, it should wait
1132 seconds before attempting to reconnect.
1133 This may happen up to
1138 The default value of ntries is zero (no reconnect).
1139 Care should be taken with this option.
1140 If the local timeout is slightly
1141 longer than the remote timeout, the reconnect feature will always be
1142 triggered (up to the given number of times) after the remote side
1143 times out and hangs up.
1144 NOTE: In this context, losing too many LQRs constitutes a loss of
1145 carrier and will trigger a reconnect.
1148 flag is specified, all phone numbers are dialed at most once until
1149 a connection is made.
1150 The next number redial period specified with the
1152 command is honoured, as is the reconnect tries value.
1154 value is less than the number of phone numbers specified, not all
1155 the specified numbers will be tried.
1156 To terminate the program, type
1157 .Bd -literal -offset indent
1158 PPP ON awfulhak> close
1159 ppp ON awfulhak> quit all
1164 command will terminate the
1168 connection but not the
1176 .Sh RECEIVING INCOMING PPP CONNECTIONS (Method 1)
1177 To handle an incoming
1179 connection request, follow these steps:
1182 Make sure the modem and (optionally)
1183 .Pa /etc/rc.d/serial
1184 is configured correctly.
1185 .Bl -bullet -compact
1187 Use Hardware Handshake (CTS/RTS) for flow control.
1189 Modem should be set to NO echo back (ATE0) and NO results string (ATQ1).
1197 on the port where the modem is attached.
1200 .Dl ttyd1 Qo /usr/libexec/getty std.38400 Qc dialup on secure
1202 Don't forget to send a
1206 process to start the
1211 It is usually also necessary to train your modem to the same DTR speed
1213 .Bd -literal -offset indent
1215 ppp ON awfulhak> set device /dev/cuaa1
1216 ppp ON awfulhak> set speed 38400
1217 ppp ON awfulhak> term
1218 deflink: Entering terminal mode on /dev/cuaa1
1229 ppp ON awfulhak> quit
1233 .Pa /usr/local/bin/ppplogin
1234 file with the following contents:
1235 .Bd -literal -offset indent
1237 exec /usr/sbin/ppp -direct incoming
1244 work with stdin and stdout.
1247 to connect to a configured diagnostic port, in the same manner as with
1253 section must be set up in
1254 .Pa /etc/ppp/ppp.conf .
1258 section contains the
1260 command as appropriate.
1262 Prepare an account for the incoming user.
1264 ppp:xxxx:66:66:PPP Login User:/home/ppp:/usr/local/bin/ppplogin
1267 Refer to the manual entries for
1273 Support for IPCP Domain Name Server and NetBIOS Name Server negotiation
1274 can be enabled using the
1279 Refer to their descriptions below.
1281 .Sh RECEIVING INCOMING PPP CONNECTIONS (Method 2)
1282 This method differs in that we use
1284 to authenticate the connection rather than
1288 Configure your default section in
1290 with automatic ppp recognition by specifying the
1295 :pp=/usr/local/bin/ppplogin:\\
1299 Configure your serial device(s), enable a
1302 .Pa /usr/local/bin/ppplogin
1303 as in the first three steps for method 1 above.
1311 .Pa /etc/ppp/ppp.conf
1314 label (or whatever label
1319 .Pa /etc/ppp/ppp.secret
1320 for each incoming user:
1329 detects a ppp connection (by recognising the HDLC frame headers), it runs
1330 .Dq /usr/local/bin/ppplogin .
1334 that either PAP or CHAP are enabled as above.
1335 If they are not, you are
1336 allowing anybody to establish a ppp session with your machine
1338 a password, opening yourself up to all sorts of potential attacks.
1339 .Sh AUTHENTICATING INCOMING CONNECTIONS
1340 Normally, the receiver of a connection requires that the peer
1341 authenticates itself.
1342 This may be done using
1344 but alternatively, you can use PAP or CHAP.
1345 CHAP is the more secure of the two, but some clients may not support it.
1346 Once you decide which you wish to use, add the command
1350 to the relevant section of
1353 You must then configure the
1354 .Pa /etc/ppp/ppp.secret
1356 This file contains one line per possible client, each line
1357 containing up to five fields:
1360 .Ar hisaddr Op Ar label Op Ar callback-number
1367 specify the client username and password.
1372 and PAP is being used,
1374 will look up the password database
1376 when authenticating.
1377 If the client does not offer a suitable response based on any
1378 .Ar name Ns No / Ns Ar key
1381 authentication fails.
1383 If authentication is successful,
1386 is used when negotiating IP numbers.
1389 command for details.
1391 If authentication is successful and
1393 is specified, the current system label is changed to match the given
1395 This will change the subsequent parsing of the
1401 If authentication is successful and
1407 the client will be called back on the given number.
1408 If CBCP is being used,
1410 may also contain a list of numbers or a
1415 The value will be used in
1417 subsequent CBCP phase.
1418 .Sh PPP OVER TCP and UDP (a.k.a Tunnelling)
1421 over a serial link, it is possible to
1422 use a TCP connection instead by specifying the host, port and protocol as the
1425 .Dl set device ui-gate:6669/tcp
1427 Instead of opening a serial device,
1429 will open a TCP connection to the given machine on the given
1431 It should be noted however that
1433 doesn't use the telnet protocol and will be unable to negotiate
1434 with a telnet server.
1435 You should set up a port for receiving this
1437 connection on the receiving machine (ui-gate).
1438 This is done by first updating
1440 to name the service:
1442 .Dl ppp-in 6669/tcp # Incoming PPP connections over TCP
1448 how to deal with incoming connections on that port:
1450 .Dl ppp-in stream tcp nowait root /usr/sbin/ppp ppp -direct ppp-in
1452 Don't forget to send a
1456 after you've updated
1457 .Pa /etc/inetd.conf .
1458 Here, we use a label named
1461 .Pa /etc/ppp/ppp.conf
1462 on ui-gate (the receiver) should contain the following:
1463 .Bd -literal -offset indent
1466 set ifaddr 10.0.4.1 10.0.4.2
1470 .Pa /etc/ppp/ppp.linkup
1472 .Bd -literal -offset indent
1474 add 10.0.1.0/24 HISADDR
1477 It is necessary to put the
1481 to ensure that the route is only added after
1483 has negotiated and assigned addresses to its interface.
1485 You may also want to enable PAP or CHAP for security.
1486 To enable PAP, add the following line:
1487 .Bd -literal -offset indent
1491 You'll also need to create the following entry in
1492 .Pa /etc/ppp/ppp.secret :
1493 .Bd -literal -offset indent
1494 MyAuthName MyAuthPasswd
1501 the password is looked up in the
1506 .Pa /etc/ppp/ppp.conf
1507 on awfulhak (the initiator) should contain the following:
1508 .Bd -literal -offset indent
1511 set device ui-gate:ppp-in/tcp
1514 set log Phase Chat Connect hdlc LCP IPCP IPV6CP CCP tun
1515 set ifaddr 10.0.4.2 10.0.4.1
1518 with the route setup in
1519 .Pa /etc/ppp/ppp.linkup :
1520 .Bd -literal -offset indent
1522 add 10.0.2.0/24 HISADDR
1525 Again, if you're enabling PAP, you'll also need this in the
1526 .Pa /etc/ppp/ppp.conf
1528 .Bd -literal -offset indent
1529 set authname MyAuthName
1530 set authkey MyAuthKey
1533 We're assigning the address of 10.0.4.1 to ui-gate, and the address
1534 10.0.4.2 to awfulhak.
1535 To open the connection, just type
1537 .Dl awfulhak # ppp -background ui-gate
1539 The result will be an additional "route" on awfulhak to the
1540 10.0.2.0/24 network via the TCP connection, and an additional
1541 "route" on ui-gate to the 10.0.1.0/24 network.
1542 The networks are effectively bridged - the underlying TCP
1543 connection may be across a public network (such as the
1546 traffic is conceptually encapsulated
1547 (although not packet by packet) inside the TCP stream between
1550 The major disadvantage of this mechanism is that there are two
1551 "guaranteed delivery" mechanisms in place - the underlying TCP
1552 stream and whatever protocol is used over the
1554 link - probably TCP again.
1555 If packets are lost, both levels will
1556 get in each others way trying to negotiate sending of the missing
1559 To avoid this overhead, it is also possible to do all this using
1560 UDP instead of TCP as the transport by simply changing the protocol
1561 from "tcp" to "udp".
1562 When using UDP as a transport,
1564 will operate in synchronous mode.
1565 This is another gain as the incoming
1566 data does not have to be rearranged into packets.
1568 Care should be taken when adding a default route through a tunneled
1570 It is quite common for the default route
1572 .Pa /etc/ppp/ppp.linkup )
1573 to end up routing the link's TCP connection through the tunnel,
1574 effectively garrotting the connection.
1575 To avoid this, make sure you add a static route for the benefit of
1577 .Bd -literal -offset indent
1580 set device ui-gate:ppp-in/tcp
1587 is the IP number that your route to
1591 When routing your connection across a public network such as the Internet,
1592 it is preferable to encrypt the data.
1593 This can be done with the help of the MPPE protocol, although currently this
1594 means that you will not be able to also compress the traffic as MPPE is
1595 implemented as a compression layer (thank Microsoft for this).
1596 To enable MPPE encryption, add the following lines to
1597 .Pa /etc/ppp/ppp.conf
1599 .Bd -literal -offset indent
1601 disable deflate pred1
1605 ensuring that you've put the requisite entry in
1606 .Pa /etc/ppp/ppp.secret
1607 (MSCHAPv2 is challenge based, so
1611 MSCHAPv2 and MPPE are accepted by default, so the client end should work
1612 without any additional changes (although ensure you have
1617 .Sh NETWORK ADDRESS TRANSLATION (PACKET ALIASING)
1620 command line option enables network address translation (a.k.a. packet
1624 host to act as a masquerading gateway for other computers over
1625 a local area network.
1626 Outgoing IP packets are NAT'd so that they appear to come from the
1628 host, and incoming packets are de-NAT'd so that they are routed
1629 to the correct machine on the local area network.
1630 NAT allows computers on private, unregistered subnets to have Internet
1631 access, although they are invisible from the outside world.
1634 operation should first be verified with network address translation disabled.
1637 option should be switched on, and network applications (web browser,
1642 should be checked on the
1645 Finally, the same or similar applications should be checked on other
1646 computers in the LAN.
1647 If network applications work correctly on the
1649 host, but not on other machines in the LAN, then the masquerading
1650 software is working properly, but the host is either not forwarding
1651 or possibly receiving IP packets.
1652 Check that IP forwarding is enabled in
1654 and that other machines have designated the
1656 host as the gateway for the LAN.
1657 .Sh PACKET FILTERING
1658 This implementation supports packet filtering.
1659 There are four kinds of
1669 Here are the basics:
1672 A filter definition has the following syntax:
1681 .Ar src_addr Ns Op / Ns Ar width
1682 .Op Ar dst_addr Ns Op / Ns Ar width
1684 .Ar [ proto Op src Ar cmp port
1689 .Op timeout Ar secs ]
1701 is a numeric value between
1705 specifying the rule number.
1706 Rules are specified in numeric order according to
1717 in which case, if a given packet matches the rule, the associated action
1718 is taken immediately.
1720 can also be specified as
1722 to clear the action associated with that particular rule, or as a new
1723 rule number greater than the current rule.
1724 In this case, if a given
1725 packet matches the current rule, the packet will next be matched against
1726 the new rule number (rather than the next rule number).
1730 may optionally be followed with an exclamation mark
1734 to reverse the sense of the following match.
1736 .Op Ar src_addr Ns Op / Ns Ar width
1738 .Op Ar dst_addr Ns Op / Ns Ar width
1739 are the source and destination IP number specifications.
1742 is specified, it gives the number of relevant netmask bits,
1743 allowing the specification of an address range.
1749 may be given the values
1755 (refer to the description of the
1757 command for a description of these values).
1758 When these values are used,
1759 the filters will be updated any time the values change.
1760 This is similar to the behaviour of the
1765 may be any protocol from
1774 meaning less-than, equal and greater-than respectively.
1776 can be specified as a numeric port or by service name from
1784 flags are only allowed when
1788 and represent the TH_ACK, TH_SYN and TH_FIN or TH_RST TCP flags respectively.
1790 The timeout value adjusts the current idle timeout to at least
1793 If a timeout is given in the alive filter as well as in the in/out
1794 filter, the in/out value is used.
1795 If no timeout is given, the default timeout (set using
1797 and defaulting to 180 seconds) is used.
1801 Each filter can hold up to 40 rules, starting from rule 0.
1802 The entire rule set is not effective until rule 0 is defined,
1803 i.e., the default is to allow everything through.
1805 If no rule in a defined set of rules matches a packet, that packet will
1806 be discarded (blocked).
1807 If there are no rules in a given filter, the packet will be permitted.
1809 It's possible to filter based on the payload of UDP frames where those
1815 .Ar filter-decapsulation
1816 option below for further details.
1819 .Dq set filter Ar name No -1
1824 .Pa /usr/share/examples/ppp/ppp.conf.sample .
1825 .Sh SETTING THE IDLE TIMER
1826 To check/set the idle timer, use the
1831 .Bd -literal -offset indent
1832 ppp ON awfulhak> set timeout 600
1835 The timeout period is measured in seconds, the default value for which
1838 To disable the idle timer function, use the command
1839 .Bd -literal -offset indent
1840 ppp ON awfulhak> set timeout 0
1847 modes, the idle timeout is ignored.
1850 mode, when the idle timeout causes the
1855 program itself remains running.
1856 Another trigger packet will cause it to attempt to re-establish the link.
1857 .Sh PREDICTOR-1 and DEFLATE COMPRESSION
1859 supports both Predictor type 1 and deflate compression.
1862 will attempt to use (or be willing to accept) both compression protocols
1863 when the peer agrees
1865 The deflate protocol is preferred by
1871 commands if you wish to disable this functionality.
1873 It is possible to use a different compression algorithm in each direction
1874 by using only one of
1878 (assuming that the peer supports both algorithms).
1880 By default, when negotiating DEFLATE,
1882 will use a window size of 15.
1885 command if you wish to change this behaviour.
1887 A special algorithm called DEFLATE24 is also available, and is disabled
1888 and denied by default.
1889 This is exactly the same as DEFLATE except that
1890 it uses CCP ID 24 to negotiate.
1893 to successfully negotiate DEFLATE with
1896 .Sh CONTROLLING IP ADDRESS
1899 uses IPCP to negotiate IP addresses.
1900 Each side of the connection
1901 specifies the IP address that it's willing to use, and if the requested
1902 IP address is acceptable then
1904 returns an ACK to the requester.
1907 returns NAK to suggest that the peer use a different IP address.
1909 both sides of the connection agree to accept the received request (and
1910 send an ACK), IPCP is set to the open state and a network level connection
1912 To control this IPCP behaviour, this implementation has the
1914 command for defining the local and remote IP address:
1915 .Bd -ragged -offset indent
1916 .No set ifaddr Oo Ar src_addr Ns
1918 .Oo Ar dst_addr Ns Op / Ns Ar \&nn
1928 is the IP address that the local side is willing to use,
1930 is the IP address which the remote side should use and
1932 is the netmask that should be used.
1934 defaults to the current
1937 defaults to 0.0.0.0, and
1939 defaults to whatever mask is appropriate for
1941 It is only possible to make
1943 smaller than the default.
1944 The usual value is 255.255.255.255, as
1945 most kernels ignore the netmask of a POINTOPOINT interface.
1949 implementations require that the peer negotiates a specific IP
1952 If this is the case,
1954 may be used to specify this IP number.
1955 This will not affect the
1956 routing table unless the other side agrees with this proposed number.
1957 .Bd -literal -offset indent
1958 set ifaddr 192.244.177.38 192.244.177.2 255.255.255.255 0.0.0.0
1961 The above specification means:
1963 .Bl -bullet -compact
1965 I will first suggest that my IP address should be 0.0.0.0, but I
1966 will only accept an address of 192.244.177.38.
1968 I strongly insist that the peer uses 192.244.177.2 as his own
1969 address and won't permit the use of any IP address but 192.244.177.2.
1970 When the peer requests another IP address, I will always suggest that
1971 it uses 192.244.177.2.
1973 The routing table entry will have a netmask of 0xffffffff.
1976 This is all fine when each side has a pre-determined IP address, however
1977 it is often the case that one side is acting as a server which controls
1978 all IP addresses and the other side should go along with it.
1979 In order to allow more flexible behaviour, the
1981 command allows the user to specify IP addresses more loosely:
1983 .Dl set ifaddr 192.244.177.38/24 192.244.177.2/20
1985 A number followed by a slash
1987 represents the number of bits significant in the IP address.
1988 The above example means:
1990 .Bl -bullet -compact
1992 I'd like to use 192.244.177.38 as my address if it is possible, but I'll
1993 also accept any IP address between 192.244.177.0 and 192.244.177.255.
1995 I'd like to make him use 192.244.177.2 as his own address, but I'll also
1996 permit him to use any IP address between 192.244.176.0 and
1999 As you may have already noticed, 192.244.177.2 is equivalent to saying
2002 As an exception, 0 is equivalent to 0.0.0.0/0, meaning that I have no
2003 preferred IP address and will obey the remote peers selection.
2004 When using zero, no routing table entries will be made until a connection
2007 192.244.177.2/0 means that I'll accept/permit any IP address but I'll
2008 suggest that 192.244.177.2 be used first.
2011 When negotiating IPv6 addresses, no control is given to the user.
2012 IPV6CP negotiation is fully automatic.
2013 .Sh CONNECTING WITH YOUR INTERNET SERVICE PROVIDER
2014 The following steps should be taken when connecting to your ISP:
2017 Describe your providers phone number(s) in the dial script using the
2020 This command allows you to set multiple phone numbers for
2021 dialing and redialing separated by either a pipe
2025 .Bd -ragged -offset indent
2026 .No set phone Ar telno Ns Xo
2027 .Oo \&| Ns Ar backupnumber
2028 .Oc Ns ... Ns Oo : Ns Ar nextnumber
2033 Numbers after the first in a pipe-separated list are only used if the
2034 previous number was used in a failed dial or login script.
2036 separated by a colon are used sequentially, irrespective of what happened
2037 as a result of using the previous number.
2039 .Bd -literal -offset indent
2040 set phone "1234567|2345678:3456789|4567890"
2043 Here, the 1234567 number is attempted.
2044 If the dial or login script fails,
2045 the 2345678 number is used next time, but *only* if the dial or login script
2047 On the dial after this, the 3456789 number is used.
2049 number is only used if the dial or login script using the 3456789 fails.
2050 If the login script of the 2345678 number fails, the next number is still the
2052 As many pipes and colons can be used as are necessary
2053 (although a given site would usually prefer to use either the pipe or the
2054 colon, but not both).
2055 The next number redial timeout is used between all numbers.
2056 When the end of the list is reached, the normal redial period is
2057 used before starting at the beginning again.
2058 The selected phone number is substituted for the \\\\T string in the
2060 command (see below).
2062 Set up your redial requirements using
2064 For example, if you have a bad telephone line or your provider is
2065 usually engaged (not so common these days), you may want to specify
2067 .Bd -literal -offset indent
2071 This says that up to 4 phone calls should be attempted with a pause of 10
2072 seconds before dialing the first number again.
2074 Describe your login procedure using the
2081 command is used to talk to your modem and establish a link with your
2083 .Bd -literal -offset indent
2084 set dial "ABORT BUSY ABORT NO\\\\sCARRIER TIMEOUT 4 \\"\\" \e
2085 ATZ OK-ATZ-OK ATDT\\\\T TIMEOUT 60 CONNECT"
2088 This modem "chat" string means:
2091 Abort if the string "BUSY" or "NO CARRIER" are received.
2093 Set the timeout to 4 seconds.
2100 If that's not received within the 4 second timeout, send ATZ
2103 Send ATDTxxxxxxx where xxxxxxx is the next number in the phone list from
2106 Set the timeout to 60.
2108 Wait for the CONNECT string.
2111 Once the connection is established, the login script is executed.
2112 This script is written in the same style as the dial script, but care should
2113 be taken to avoid having your password logged:
2114 .Bd -literal -offset indent
2115 set authkey MySecret
2116 set login "TIMEOUT 15 login:-\\\\r-login: awfulhak \e
2117 word: \\\\P ocol: PPP HELLO"
2120 This login "chat" string means:
2123 Set the timeout to 15 seconds.
2126 If it's not received, send a carriage return and expect
2131 Expect "word:" (the tail end of a "Password:" prompt).
2133 Send whatever our current
2137 Expect "ocol:" (the tail end of a "Protocol:" prompt).
2146 command is logged specially.
2151 logging is enabled, the actual password is not logged;
2155 Login scripts vary greatly between ISPs.
2156 If you're setting one up for the first time,
2157 .Em ENABLE CHAT LOGGING
2158 so that you can see if your script is behaving as you expect.
2164 to specify your serial line and speed, for example:
2165 .Bd -literal -offset indent
2166 set device /dev/cuaa0
2170 Cuaa0 is the first serial port on
2177 A speed of 115200 should be specified
2178 if you have a modem capable of bit rates of 28800 or more.
2179 In general, the serial speed should be about four times the modem speed.
2183 command to {define} the IP address.
2186 If you know what IP address your provider uses, then use it as the remote
2187 address (dst_addr), otherwise choose something like 10.0.0.2/0 (see below).
2189 If your provider has assigned a particular IP address to you, then use
2190 it as your address (src_addr).
2192 If your provider assigns your address dynamically, choose a suitably
2193 unobtrusive and unspecific IP number as your address.
2194 10.0.0.1/0 would be appropriate.
2195 The bit after the / specifies how many bits of the
2196 address you consider to be important, so if you wanted to insist on
2197 something in the class C network 1.2.3.0, you could specify 1.2.3.1/24.
2199 If you find that your ISP accepts the first IP number that you suggest,
2200 specify third and forth arguments of
2202 This will force your ISP to assign a number.
2203 (The third argument will
2204 be ignored as it is less restrictive than the default mask for your
2208 An example for a connection where you don't know your IP number or your
2209 ISPs IP number would be:
2210 .Bd -literal -offset indent
2211 set ifaddr 10.0.0.1/0 10.0.0.2/0 0.0.0.0 0.0.0.0
2215 In most cases, your ISP will also be your default router.
2216 If this is the case, add the line
2217 .Bd -literal -offset indent
2222 .Pa /etc/ppp/ppp.conf
2224 .Pa /etc/ppp/ppp.linkup
2225 for setups that don't use
2231 to add a default route to whatever the peer address is
2232 (10.0.0.2 in this example).
2235 meaning that should the value of
2237 change, the route will be updated accordingly.
2239 If your provider requests that you use PAP/CHAP authentication methods, add
2240 the next lines to your
2241 .Pa /etc/ppp/ppp.conf
2243 .Bd -literal -offset indent
2245 set authkey MyPassword
2248 Both are accepted by default, so
2250 will provide whatever your ISP requires.
2252 It should be noted that a login script is rarely (if ever) required
2253 when PAP or CHAP are in use.
2255 Ask your ISP to authenticate your nameserver address(es) with the line
2256 .Bd -literal -offset indent
2262 do this if you are running a local DNS unless you also either use
2267 .Pa /etc/ppp/ppp.linkdown ,
2270 will simply circumvent its use by entering some nameserver lines in
2271 .Pa /etc/resolv.conf .
2275 .Pa /usr/share/examples/ppp/ppp.conf.sample
2277 .Pa /usr/share/examples/ppp/ppp.linkup.sample
2278 for some real examples.
2279 The pmdemand label should be appropriate for most ISPs.
2280 .Sh LOGGING FACILITY
2282 is able to generate the following log info either via
2284 or directly to the screen:
2286 .Bl -tag -width XXXXXXXXX -offset XXX -compact
2288 Enable all logging facilities.
2289 This generates a lot of log.
2290 The most common use of 'all' is as a basis, where you remove some facilities
2291 after enabling 'all' ('debug' and 'timer' are usually best disabled.)
2293 Dump async level packet in hex.
2295 Generate CBCP (CallBack Control Protocol) logs.
2297 Generate a CCP packet trace.
2305 chat script trace logs.
2307 Log commands executed either from the command line or any of the configuration
2310 Log Chat lines containing the string "CONNECT".
2312 Log debug information.
2314 Log DNS QUERY packets.
2316 Log packets permitted by the dial filter and denied by any filter.
2318 Dump HDLC packet in hex.
2320 Log all function calls specifically made as user id 0.
2322 Generate an IPCP packet trace.
2324 Generate an LCP packet trace.
2326 Generate LQR reports.
2328 Phase transition log output.
2330 Dump physical level packet in hex.
2332 Dump sync level packet in hex.
2334 Dump all TCP/IP packets.
2336 Log timer manipulation.
2338 Include the tun device on each log line.
2340 Output to the terminal device.
2341 If there is currently no terminal,
2342 output is sent to the log file using syslogs
2345 Output to both the terminal device
2346 and the log file using syslogs
2349 Output to the log file using
2355 command allows you to set the logging output level.
2356 Multiple levels can be specified on a single command line.
2357 The default is equivalent to
2360 It is also possible to log directly to the screen.
2361 The syntax is the same except that the word
2363 should immediately follow
2367 (i.e., only the un-maskable warning, error and alert output).
2369 If The first argument to
2370 .Dq set log Op local
2375 character, the current log levels are
2376 not cleared, for example:
2377 .Bd -literal -offset indent
2378 PPP ON awfulhak> set log phase
2379 PPP ON awfulhak> show log
2380 Log: Phase Warning Error Alert
2381 Local: Warning Error Alert
2382 PPP ON awfulhak> set log +tcp/ip -warning
2383 PPP ON awfulhak> set log local +command
2384 PPP ON awfulhak> show log
2385 Log: Phase TCP/IP Warning Error Alert
2386 Local: Command Warning Error Alert
2389 Log messages of level Warning, Error and Alert are not controllable
2391 .Dq set log Op local .
2395 level is special in that it will not be logged if it can be displayed
2399 deals with the following signals:
2400 .Bl -tag -width "USR2"
2402 Receipt of this signal causes the termination of the current connection
2406 to exit unless it is in
2411 .It HUP, TERM & QUIT
2418 to re-open any existing server socket, dropping all existing diagnostic
2420 Sockets that couldn't previously be opened will be retried.
2424 to close any existing server socket, dropping all existing diagnostic
2427 can still be used to re-open the socket.
2430 If you wish to use more than one physical link to connect to a
2432 peer, that peer must also understand the
2435 Refer to RFC 1990 for specification details.
2437 The peer is identified using a combination of his
2438 .Dq endpoint discriminator
2440 .Dq authentication id .
2441 Either or both of these may be specified.
2442 It is recommended that
2443 at least one is specified, otherwise there is no way of ensuring that
2444 all links are actually connected to the same peer program, and some
2445 confusing lock-ups may result.
2446 Locally, these identification variables are specified using the
2455 must be agreed in advance with the peer.
2457 Multi-link capabilities are enabled using the
2459 command (set maximum reconstructed receive unit).
2460 Once multi-link is enabled,
2462 will attempt to negotiate a multi-link connection with the peer.
2464 By default, only one
2469 To create more links, the
2472 This command will clone existing links, where all
2473 characteristics are the same except:
2476 The new link has its own name as specified on the
2483 Its mode may subsequently be changed using the
2487 The new link is in a
2492 A summary of all available links can be seen using the
2496 Once a new link has been created, command usage varies.
2497 All link specific commands must be prefixed with the
2499 command, specifying on which link the command is to be applied.
2500 When only a single link is available,
2502 is smart enough not to require the
2506 Some commands can still be used without specifying a link - resulting
2507 in an operation at the
2510 For example, once two or more links are available, the command
2512 will show CCP configuration and statistics at the multi-link level, and
2513 .Dq link deflink show ccp
2514 will show the same information at the
2518 Armed with this information, the following configuration might be used:
2519 .Bd -literal -offset indent
2523 set device /dev/cuaa0 /dev/cuaa1 /dev/cuaa2
2524 set phone "123456789"
2525 set dial "ABORT BUSY ABORT NO\\sCARRIER TIMEOUT 5 \\"\\" ATZ \e
2526 OK-AT-OK \\\\dATDT\\\\T TIMEOUT 45 CONNECT"
2528 set ifaddr 10.0.0.1/0 10.0.0.2/0 0.0.0.0 0.0.0.0
2530 set authkey ppppassword
2533 clone 1,2,3 # Create 3 new links - duplicates of the default
2534 link deflink remove # Delete the default link (called ``deflink'')
2537 Note how all cloning is done at the end of the configuration.
2538 Usually, the link will be configured first, then cloned.
2539 If you wish all links
2540 to be up all the time, you can add the following line to the end of your
2542 .Bd -literal -offset indent
2543 link 1,2,3 set mode ddial
2546 If you want the links to dial on demand, this command could be used:
2547 .Bd -literal -offset indent
2548 link * set mode auto
2551 Links may be tied to specific names by removing the
2553 line above, and specifying the following after the
2556 .Bd -literal -offset indent
2557 link 1 set device /dev/cuaa0
2558 link 2 set device /dev/cuaa1
2559 link 3 set device /dev/cuaa2
2564 command to see which commands require context (using the
2566 command), which have optional
2567 context and which should not have any context.
2573 mode with the peer, it creates a local domain socket in the
2576 This socket is used to pass link information (including
2577 the actual link file descriptor) between different
2582 ability to be run from a
2588 capability), without needing to have initial control of the serial
2592 negotiates multi-link mode, it will pass its open link to any
2593 already running process.
2594 If there is no already running process,
2596 will act as the master, creating the socket and listening for new
2598 .Sh PPP COMMAND LIST
2599 This section lists the available commands and their effect.
2600 They are usable either from an interactive
2602 session, from a configuration file or from a
2608 .It accept|deny|enable|disable Ar option....
2609 These directives tell
2611 how to negotiate the initial connection with the peer.
2614 has a default of either accept or deny and enable or disable.
2616 means that the option will be ACK'd if the peer asks for it.
2618 means that the option will be NAK'd if the peer asks for it.
2620 means that the option will be requested by us.
2622 means that the option will not be requested by us.
2625 may be one of the following:
2628 Default: Enabled and Accepted.
2629 ACFComp stands for Address and Control Field Compression.
2630 Non LCP packets will usually have an address
2631 field of 0xff (the All-Stations address) and a control field of
2632 0x03 (the Unnumbered Information command).
2634 negotiated, these two bytes are simply not sent, thus minimising
2641 Default: Disabled and Accepted.
2642 CHAP stands for Challenge Handshake Authentication Protocol.
2643 Only one of CHAP and PAP (below) may be negotiated.
2644 With CHAP, the authenticator sends a "challenge" message to its peer.
2645 The peer uses a one-way hash function to encrypt the
2646 challenge and sends the result back.
2647 The authenticator does the same, and compares the results.
2648 The advantage of this mechanism is that no
2649 passwords are sent across the connection.
2650 A challenge is made when the connection is first made.
2651 Subsequent challenges may occur.
2652 If you want to have your peer authenticate itself, you must
2655 .Pa /etc/ppp/ppp.conf ,
2656 and have an entry in
2657 .Pa /etc/ppp/ppp.secret
2660 When using CHAP as the client, you need only specify
2665 .Pa /etc/ppp/ppp.conf .
2666 CHAP is accepted by default.
2669 implementations use "MS-CHAP" rather than MD5 when encrypting the
2671 MS-CHAP is a combination of MD4 and DES.
2674 was built on a machine with DES libraries available, it will respond
2675 to MS-CHAP authentication requests, but will never request them.
2677 Default: Enabled and Accepted.
2678 This option decides if deflate
2679 compression will be used by the Compression Control Protocol (CCP).
2680 This is the same algorithm as used by the
2683 Note: There is a problem negotiating
2689 implementation available under many operating systems.
2691 (version 2.3.1) incorrectly attempts to negotiate
2693 compression using type
2695 as the CCP configuration type rather than type
2701 is actually specified as
2702 .Dq PPP Magna-link Variable Resource Compression
2706 is capable of negotiating with
2713 .Ar accept Ns No ed .
2715 Default: Disabled and Denied.
2716 This is a variance of the
2718 option, allowing negotiation with the
2723 section above for details.
2724 It is disabled by default as it violates
2727 Default: Disabled and Denied.
2728 This option allows DNS negotiation.
2733 will request that the peer confirms the entries in
2734 .Pa /etc/resolv.conf .
2735 If the peer NAKs our request (suggesting new IP numbers),
2736 .Pa /etc/resolv.conf
2737 is updated and another request is sent to confirm the new entries.
2740 .Dq accept Ns No ed,
2742 will answer any DNS queries requested by the peer rather than rejecting
2744 The answer is taken from
2745 .Pa /etc/resolv.conf
2748 command is used as an override.
2750 Default: Enabled and Accepted.
2751 This option allows control over whether we
2752 negotiate an endpoint discriminator.
2753 We only send our discriminator if
2758 We reject the peers discriminator if
2762 Default: Disabled and Accepted.
2763 The use of this authentication protocol
2764 is discouraged as it partially violates the authentication protocol by
2765 implementing two different mechanisms (LANMan & NT) under the guise of
2766 a single CHAP type (0x80).
2768 uses a simple DES encryption mechanism and is the least secure of the
2769 CHAP alternatives (although is still more secure than PAP).
2773 description below for more details.
2775 Default: Disabled and Accepted.
2776 This option decides if Link Quality Requests will be sent or accepted.
2777 LQR is a protocol that allows
2779 to determine that the link is down without relying on the modems
2781 When LQR is enabled,
2787 below) as part of the LCP request.
2788 If the peer agrees, both sides will
2789 exchange LQR packets at the agreed frequency, allowing detailed link
2790 quality monitoring by enabling LQM logging.
2791 If the peer doesn't agree,
2793 will send ECHO LQR requests instead.
2794 These packets pass no information of interest, but they
2796 be replied to by the peer.
2798 Whether using LQR or ECHO LQR,
2800 will abruptly drop the connection if 5 unacknowledged packets have been
2801 sent rather than sending a 6th.
2802 A message is logged at the
2804 level, and any appropriate
2806 values are honoured as if the peer were responsible for dropping the
2809 Default: Enabled and Accepted.
2810 This is Microsoft Point to Point Encryption scheme.
2811 MPPE key size can be
2812 40-, 56- and 128-bits.
2817 Default: Disabled and Accepted.
2818 It is very similar to standard CHAP (type 0x05)
2819 except that it issues challenges of a fixed 16 bytes in length and uses a
2820 combination of MD4, SHA-1 and DES to encrypt the challenge rather than using the
2821 standard MD5 mechanism.
2823 Default: Disabled and Accepted.
2824 The use of this authentication protocol
2825 is discouraged as it partially violates the authentication protocol by
2826 implementing two different mechanisms (LANMan & NT) under the guise of
2827 a single CHAP type (0x80).
2828 It is very similar to standard CHAP (type 0x05)
2829 except that it issues challenges of a fixed 8 bytes in length and uses a
2830 combination of MD4 and DES to encrypt the challenge rather than using the
2831 standard MD5 mechanism.
2832 CHAP type 0x80 for LANMan is also supported - see
2840 use CHAP type 0x80, when acting as authenticator with both
2841 .Dq enable Ns No d ,
2843 will rechallenge the peer up to three times if it responds using the wrong
2844 one of the two protocols.
2845 This gives the peer a chance to attempt using both protocols.
2849 acts as the authenticatee with both protocols
2850 .Dq accept Ns No ed ,
2851 the protocols are used alternately in response to challenges.
2853 Note: If only LANMan is enabled,
2855 (version 2.3.5) misbehaves when acting as authenticatee.
2857 the NT and the LANMan answers, but also suggests that only the NT answer
2860 Default: Disabled and Accepted.
2861 PAP stands for Password Authentication Protocol.
2862 Only one of PAP and CHAP (above) may be negotiated.
2863 With PAP, the ID and Password are sent repeatedly to the peer until
2864 authentication is acknowledged or the connection is terminated.
2865 This is a rather poor security mechanism.
2866 It is only performed when the connection is first established.
2867 If you want to have your peer authenticate itself, you must
2870 .Pa /etc/ppp/ppp.conf ,
2871 and have an entry in
2872 .Pa /etc/ppp/ppp.secret
2873 for the peer (although see the
2879 When using PAP as the client, you need only specify
2884 .Pa /etc/ppp/ppp.conf .
2885 PAP is accepted by default.
2887 Default: Enabled and Accepted.
2888 This option decides if Predictor 1
2889 compression will be used by the Compression Control Protocol (CCP).
2891 Default: Enabled and Accepted.
2892 This option is used to negotiate
2893 PFC (Protocol Field Compression), a mechanism where the protocol
2894 field number is reduced to one octet rather than two.
2896 Default: Enabled and Accepted.
2897 This option determines if
2899 will request and accept requests for short
2901 sequence numbers when negotiating multi-link mode.
2902 This is only applicable if our MRRU is set (thus enabling multi-link).
2904 Default: Enabled and Accepted.
2905 This option determines if Van Jacobson header compression will be used.
2908 The following options are not actually negotiated with the peer.
2909 Therefore, accepting or denying them makes no sense.
2911 .It filter-decapsulation
2913 When this option is enabled,
2915 will examine UDP frames to see if they actually contain a
2917 frame as their payload.
2918 If this is the case, all filters will operate on the payload rather
2919 than the actual packet.
2921 This is useful if you want to send PPPoUDP traffic over a
2923 link, but want that link to do smart things with the real data rather than
2926 The UDP frame payload must not be compressed in any way, otherwise
2928 will not be able to interpret it.
2929 It's therefore recommended that you
2930 .Ic disable vj pred1 deflate
2932 .Ic deny vj pred1 deflate
2933 in the configuration for the
2935 invocation with the udp link.
2940 exchanges low-level LCP, CCP and IPCP configuration traffic, the
2942 field of any replies is expected to be the same as that of the request.
2945 drops any reply packets that do not contain the expected identifier
2946 field, reporting the fact at the respective log level.
2951 will ignore the identifier field.
2956 This option simply tells
2958 to add new interface addresses to the interface rather than replacing them.
2959 The option can only be enabled if network address translation is enabled
2960 .Pq Dq nat enable yes .
2962 With this option enabled,
2964 will pass traffic for old interface addresses through the NAT
2965 ifdef({LOCALNAT},{engine,},{engine
2967 .Xr libalias 3 ) ,})
2968 resulting in the ability (in
2970 mode) to properly connect the process that caused the PPP link to
2971 come up in the first place.
2981 to attempt to negotiate IP control protocol capabilities and if
2982 successful to exchange IP datagrams with the peer.
2987 to attempt to negotiate IPv6 control protocol capabilities and if
2988 successful to exchange IPv6 datagrams with the peer.
2993 runs as a Multi-link server, a different
2995 instance initially receives each connection.
2996 After determining that
2997 the link belongs to an already existing bundle (controlled by another
3001 will transfer the link to that process.
3003 If the link is a tty device or if this option is enabled,
3005 will not exit, but will change its process name to
3007 and wait for the controlling
3009 to finish with the link and deliver a signal back to the idle process.
3010 This prevents the confusion that results from
3012 parent considering the link resource available again.
3014 For tty devices that have entries in
3016 this is necessary to prevent another
3018 from being started, and for program links such as
3022 from exiting due to the death of its child.
3025 cannot determine its parents requirements (except for the tty case), this
3026 option must be enabled manually depending on the circumstances.
3033 will automatically loop back packets being sent
3034 out with a destination address equal to that of the
3039 will send the packet, probably resulting in an ICMP redirect from
3041 It is convenient to have this option enabled when
3042 the interface is also the default route as it avoids the necessity
3043 of a loopback route.
3046 Enabling this option will tell the PAP authentication
3047 code to use the password database (see
3049 to authenticate the caller if they cannot be found in the
3050 .Pa /etc/ppp/ppp.secret
3052 .Pa /etc/ppp/ppp.secret
3053 is always checked first.
3054 If you wish to use passwords from
3056 but also to specify an IP number or label for a given client, use
3058 as the client password in
3059 .Pa /etc/ppp/ppp.secret .
3062 Enabling this option will tell
3064 to proxy ARP for the peer.
3067 will make an entry in the ARP table using
3071 address of the local network in which
3074 This allows other machines connected to the LAN to talk to
3075 the peer as if the peer itself was connected to the LAN.
3076 The proxy entry cannot be made unless
3078 is an address from a LAN.
3081 Enabling this will tell
3083 to add proxy arp entries for every IP address in all class C or
3084 smaller subnets routed via the tun interface.
3086 Proxy arp entries are only made for sticky routes that are added
3090 No proxy arp entries are made for the interface address itself
3098 command is used with the
3104 values, entries are stored in the
3107 Each time these variables change, this list is re-applied to the routing table.
3109 Disabling this option will prevent the re-application of sticky routes,
3112 list will still be maintained.
3119 to adjust TCP SYN packets so that the maximum receive segment
3120 size is not greater than the amount allowed by the interface MTU.
3125 to gather throughput statistics.
3126 Input and output is sampled over
3127 a rolling 5 second window, and current, best and total figures are retained.
3128 This data is output when the relevant
3130 layer shuts down, and is also available using the
3133 Throughput statistics are available at the
3140 Normally, when a user is authenticated using PAP or CHAP, and when
3144 mode, an entry is made in the utmp and wtmp files for that user.
3145 Disabling this option will tell
3147 not to make any utmp or wtmp entries.
3148 This is usually only necessary if
3149 you require the user to both login and authenticate themselves.
3154 .Ar dest Ns Op / Ns Ar nn
3159 is the destination IP address.
3160 The netmask is specified either as a number of bits with
3162 or as an IP number using
3167 with no mask refers to the default route.
3168 It is also possible to use the literal name
3173 is the next hop gateway to get to the given
3178 command for further details.
3180 It is possible to use the symbolic names
3186 as the destination, and
3193 is replaced with the interface IP address,
3195 is replaced with the interface IP destination (peer) address,
3197 is replaced with the interface IPv6 address, and
3199 is replaced with the interface IPv6 destination address,
3206 then if the route already exists, it will be updated as with the
3210 for further details).
3212 Routes that contain the
3220 constants are considered
3222 They are stored in a list (use
3224 to see the list), and each time the value of one of these variables
3225 changes, the appropriate routing table entries are updated.
3226 This facility may be disabled using
3227 .Dq disable sroutes .
3228 .It allow Ar command Op Ar args
3229 This command controls access to
3231 and its configuration files.
3232 It is possible to allow user-level access,
3233 depending on the configuration file label and on the mode that
3236 For example, you may wish to configure
3246 User id 0 is immune to these commands.
3248 .It allow user Ns Xo
3250 .Ar logname Ns No ...
3252 By default, only user id 0 is allowed access to
3254 If this command is used, all of the listed users are allowed access to
3255 the section in which the
3260 section is always checked first (even though it is only ever automatically
3263 commands are cumulative in a given section, but users allowed in any given
3264 section override users allowed in the default section, so it's possible to
3265 allow users access to everything except a given label by specifying default
3268 section, and then specifying a new user list for that label.
3272 is specified, access is allowed to all users.
3273 .It allow mode Ns Xo
3277 By default, access using any
3280 If this command is used, it restricts the access
3282 allowed to load the label under which this command is specified.
3287 command overrides any previous settings, and the
3289 section is always checked first.
3301 When running in multi-link mode, a section can be loaded if it allows
3303 of the currently existing line modes.
3306 .It nat Ar command Op Ar args
3307 This command allows the control of the network address translation (also
3308 known as masquerading or IP aliasing) facilities that are built into
3310 NAT is done on the external interface only, and is unlikely to make sense
3315 If nat is enabled on your system (it may be omitted at compile time),
3316 the following commands are possible:
3318 .It nat enable yes|no
3319 This command either switches network address translation on or turns it off.
3322 command line flag is synonymous with
3323 .Dq nat enable yes .
3324 .It nat addr Op Ar addr_local addr_alias
3325 This command allows data for
3329 It is useful if you own a small number of real IP numbers that
3330 you wish to map to specific machines behind your gateway.
3331 .It nat deny_incoming yes|no
3332 If set to yes, this command will refuse all incoming packets where an
3333 aliasing link doesn't already exist.
3334 ifdef({LOCALNAT},{},{Refer to the
3335 .Sx CONCEPTUAL BACKGROUND
3338 for a description of what an
3343 It should be noted under what circumstances an aliasing link is
3344 ifdef({LOCALNAT},{created.},{created by
3346 It may be necessary to further protect your network from outside
3347 connections using the
3353 This command gives a summary of available nat commands.
3355 This option causes various NAT statistics and information to
3356 be logged to the file
3357 .Pa /var/log/alias.log .
3358 .It nat port Ar proto Ar targetIP Ns Xo
3359 .No : Ns Ar targetPort Ns
3361 .No - Ns Ar targetPort
3364 .No - Ns Ar aliasPort
3365 .Oc Oo Ar remoteIP : Ns
3368 .No - Ns Ar remotePort
3372 This command causes incoming
3386 A range of port numbers may be specified as shown above.
3387 The ranges must be of the same size.
3391 is specified, only data coming from that IP number is redirected.
3395 (indicating any source port)
3396 or a range of ports the same size as the other ranges.
3398 This option is useful if you wish to run things like Internet phone on
3399 machines behind your gateway, but is limited in that connections to only
3400 one interior machine per source machine and target port are possible.
3401 .It nat proto Ar proto localIP Oo
3402 .Ar publicIP Op Ar remoteIP
3406 to redirect packets of protocol type
3410 to the internal address
3415 is specified, only packets destined for that address are matched,
3416 otherwise the default alias address is used.
3420 is specified, only packets matching that source address are matched,
3422 This command is useful for redirecting tunnel endpoints to an internal machine,
3425 .Dl nat proto ipencap 10.0.0.1
3426 .It "nat proxy cmd" Ar arg Ns No ...
3429 to proxy certain connections, redirecting them to a given server.
3430 ifdef({LOCALNAT},{},{Refer to the description of
3431 .Fn PacketAliasProxyRule
3434 for details of the available commands.
3436 .It nat punch_fw Op Ar base count
3439 to punch holes in the firewall for FTP or IRC DCC connections.
3440 This is done dynamically by installing temporary firewall rules which
3441 allow a particular connection (and only that connection) to go through
3443 The rules are removed once the corresponding connection terminates.
3447 rules starting from rule number
3449 will be used for punching firewall holes.
3450 The range will be cleared when the
3454 If no arguments are given, firewall punching is disabled.
3455 .It nat same_ports yes|no
3456 When enabled, this command will tell the network address translation engine to
3457 attempt to avoid changing the port number on outgoing packets.
3459 if you want to support protocols such as RPC and LPD which require
3460 connections to come from a well known port.
3461 .It nat target Op Ar address
3462 Set the given target address or clear it if no address is given.
3463 The target address is used
3464 ifdef({LOCALNAT},{},{by libalias })dnl
3465 to specify how to NAT incoming packets by default.
3466 If a target address is not set or if
3468 is given, packets are not altered and are allowed to route to the internal
3471 The target address may be set to
3474 ifdef({LOCALNAT},{all packets will be redirected},
3475 {libalias will redirect all packets})
3476 to the interface address.
3477 .It nat use_sockets yes|no
3478 When enabled, this option tells the network address translation engine to
3479 create a socket so that it can guarantee a correct incoming ftp data or
3481 .It nat unregistered_only yes|no
3482 Only alter outgoing packets with an unregistered source address.
3483 According to RFC 1918, unregistered source addresses
3484 are 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16.
3487 These commands are also discussed in the file
3489 which comes with the source distribution.
3496 is executed in the background with the following words replaced:
3497 .Bl -tag -width COMPILATIONDATE
3499 This is replaced with the local
3505 .It Li COMPILATIONDATE
3506 This is replaced with the date on which
3510 These are replaced with the primary and secondary nameserver IP numbers.
3511 If nameservers are negotiated by IPCP, the values of these macros will change.
3513 This is replaced with the local endpoint discriminator value.
3518 This is replaced with the peers IP number.
3520 This is replaced with the peers IPv6 number.
3522 This is replaced with the name of the interface that's in use.
3524 This is replaced with the number of IP bytes received since the connection
3527 This is replaced with the number of IP bytes sent since the connection
3530 This is replaced with the number of IP packets received since the connection
3533 This is replaced with the number of IP packets sent since the connection
3536 This is replaced with the number of IPv6 bytes received since the connection
3538 .It Li IPV6OCTETSOUT
3539 This is replaced with the number of IPv6 bytes sent since the connection
3541 .It Li IPV6PACKETSIN
3542 This is replaced with the number of IPv6 packets received since the connection
3544 .It Li IPV6PACKETSOUT
3545 This is replaced with the number of IPv6 packets sent since the connection
3548 This is replaced with the last label name used.
3549 A label may be specified on the
3551 command line, via the
3559 This is replaced with the IP number assigned to the local interface.
3561 This is replaced with the IPv6 number assigned to the local interface.
3563 This is replaced with the number of bytes received since the connection
3566 This is replaced with the number of bytes sent since the connection
3569 This is replaced with the number of packets received since the connection
3572 This is replaced with the number of packets sent since the connection
3575 This is replaced with the value of the peers endpoint discriminator.
3577 This is replaced with the current process id.
3579 This is replaced with the name of the diagnostic socket.
3581 This is replaced with the bundle uptime in HH:MM:SS format.
3583 This is replaced with the username that has been authenticated with PAP or
3585 Normally, this variable is assigned only in -direct mode.
3586 This value is available irrespective of whether utmp logging is enabled.
3588 This is replaced with the current version number of
3592 These substitutions are also done by the
3599 If you wish to pause
3601 while the command executes, use the
3604 .It clear physical|ipcp|ipv6 Op current|overall|peak...
3605 Clear the specified throughput values at either the
3613 is specified, context must be given (see the
3616 If no second argument is given, all values are cleared.
3617 .It clone Ar name Ns Xo
3618 .Op \&, Ns Ar name Ns
3621 Clone the specified link, creating one or more new links according to the
3624 This command must be used from the
3626 command below unless you've only got a single link (in which case that
3627 link becomes the default).
3628 Links may be removed using the
3632 The default link name is
3634 .It close Op lcp|ccp Ns Op !\&
3635 If no arguments are given, the relevant protocol layers will be brought
3636 down and the link will be closed.
3639 is specified, the LCP layer is brought down, but
3641 will not bring the link offline.
3642 It is subsequently possible to use
3645 to talk to the peer machine if, for example, something like
3650 is specified, only the relevant compression layer is closed.
3653 is used, the compression layer will remain in the closed state, otherwise
3654 it will re-enter the STOPPED state, waiting for the peer to initiate
3655 further CCP negotiation.
3656 In any event, this command does not disconnect the user from
3667 This command deletes the route with the given
3674 all non-direct entries in the routing table for the current interface,
3677 entries are deleted.
3682 the default route is deleted.
3690 will not complain if the route does not already exist.
3691 .It dial|call Op Ar label Ns Xo
3694 This command is the equivalent of
3698 and is provided for backwards compatibility.
3699 .It down Op Ar lcp|ccp
3700 Bring the relevant layer down ungracefully, as if the underlying layer
3701 had become unavailable.
3702 It's not considered polite to use this command on
3703 a Finite State Machine that's in the OPEN state.
3705 supplied, the entire link is closed (or if no context is given, all links
3711 layer is terminated but the device is not brought offline and the link
3715 is specified, only the relevant compression layer(s) are terminated.
3716 .It help|? Op Ar command
3717 Show a list of available commands.
3720 is specified, show the usage string for that command.
3721 .It ident Op Ar text Ns No ...
3722 Identify the link to the peer using
3726 is empty, link identification is disabled.
3727 It is possible to use any of the words described for the
3732 command for details of when
3734 identifies itself to the peer.
3735 .It iface Ar command Op args
3736 This command is used to control the interface used by
3739 may be one of the following:
3743 .Ar addr Ns Op / Ns Ar bits
3754 combination to the interface.
3755 Instead of specifying
3759 (with no space between it and
3761 If the given address already exists, the command fails unless the
3763 is used - in which case the previous interface address entry is overwritten
3764 with the new one, allowing a change of netmask or peer address.
3775 .Dq 255.255.255.255 .
3776 This address (the broadcast address) is the only duplicate peer address that
3779 .It iface clear Op INET | INET6
3780 If this command is used while
3782 is in the OPENED state or while in
3784 mode, all addresses except for the NCP negotiated address are deleted
3788 is not in the OPENED state and is not in
3790 mode, all interface addresses are deleted.
3792 If the INET or INET6 arguments are used, only addresses for that address
3795 .It iface delete Ns Xo
3800 This command deletes the given
3805 is used, no error is given if the address isn't currently assigned to
3806 the interface (and no deletion takes place).
3808 Shows the current state and current addresses for the interface.
3809 It is much the same as running
3810 .Dq ifconfig INTERFACE .
3811 .It iface help Op Ar sub-command
3812 This command, when invoked without
3814 will show a list of possible
3816 sub-commands and a brief synopsis for each.
3819 only the synopsis for the given sub-command is shown.
3823 .Ar name Ns Op , Ns Ar name Ns
3824 .No ... Ar command Op Ar args
3826 This command may prefix any other command if the user wishes to
3827 specify which link the command should affect.
3828 This is only applicable after multiple links have been created in Multi-link
3834 specifies the name of an existing link.
3837 is a comma separated list,
3839 is executed on each link.
3845 is executed on all links.
3846 .It load Op Ar label Ns Xo
3869 will not attempt to make an immediate connection.
3870 .It log Ar word Ns No ...
3871 Send the given word(s) to the log file with the prefix
3873 Word substitutions are done as explained under the
3876 .It open Op lcp|ccp|ipcp
3877 This is the opposite of the
3880 All closed links are immediately brought up apart from second and subsequent
3882 links - these will come up based on the
3884 command that has been used.
3888 argument is used while the LCP layer is already open, LCP will be
3890 This allows various LCP options to be changed, after which
3892 can be used to put them into effect.
3893 After renegotiating LCP,
3894 any agreed authentication will also take place.
3898 argument is used, the relevant compression layer is opened.
3899 Again, if it is already open, it will be renegotiated.
3903 argument is used, the link will be brought up as normal, but if
3904 IPCP is already open, it will be renegotiated and the network
3905 interface will be reconfigured.
3907 It is probably not good practice to re-open the PPP state machines
3908 like this as it's possible that the peer will not behave correctly.
3911 however useful as a way of forcing the CCP or VJ dictionaries to be reset.
3913 Specify the password required for access to the full
3916 This password is required when connecting to the diagnostic port (see the
3927 logging is active, instead, the literal string
3933 is executed from the controlling connection or from a command file,
3934 ppp will exit after closing all connections.
3935 Otherwise, if the user
3936 is connected to a diagnostic socket, the connection is simply dropped.
3942 will exit despite the source of the command after closing all existing
3945 This command removes the given link.
3946 It is only really useful in multi-link mode.
3947 A link must be in the
3949 state before it is removed.
3950 .It rename|mv Ar name
3951 This command renames the given link to
3955 is already used by another link.
3957 The default link name is
3964 may make the log file more readable.
3965 .It resolv Ar command
3966 This command controls
3973 starts up, it loads the contents of this file into memory and retains this
3974 image for future use.
3976 is one of the following:
3977 .Bl -tag -width readonly
3980 .Pa /etc/resolv.conf
3986 will still attempt to negotiate nameservers with the peer, making the results
3992 This is the opposite of the
3997 .Pa /etc/resolv.conf
3999 This may be necessary if for example a DHCP client overwrote
4000 .Pa /etc/resolv.conf .
4003 .Pa /etc/resolv.conf
4004 with the version originally read at startup or with the last
4007 This is sometimes a useful command to put in the
4008 .Pa /etc/ppp/ppp.linkdown
4012 .Pa /etc/resolv.conf
4014 This command will work even if the
4016 command has been used.
4017 It may be useful as a command in the
4018 .Pa /etc/ppp/ppp.linkup
4019 file if you wish to defer updating
4020 .Pa /etc/resolv.conf
4021 until after other commands have finished.
4026 .Pa /etc/resolv.conf
4031 successfully negotiates a DNS.
4032 This is the opposite of the
4037 This option is not (yet) implemented.
4041 to identify itself to the peer.
4042 The link must be in LCP state or higher.
4043 If no identity has been set (via the
4049 When an identity has been set,
4051 will automatically identify itself when it sends or receives a configure
4052 reject, when negotiation fails or when LCP reaches the opened state.
4054 Received identification packets are logged to the LCP log (see
4056 for details) and are never responded to.
4061 This option allows the setting of any of the following variables:
4063 .It set accmap Ar hex-value
4064 ACCMap stands for Asynchronous Control Character Map.
4066 negotiated with the peer, and defaults to a value of 00000000 in hex.
4067 This protocol is required to defeat hardware that depends on passing
4068 certain characters from end to end (such as XON/XOFF etc).
4070 For the XON/XOFF scenario, use
4071 .Dq set accmap 000a0000 .
4072 .It set Op auth Ns Xo
4075 This sets the authentication key (or password) used in client mode
4076 PAP or CHAP negotiation to the given value.
4077 It also specifies the
4078 password to be used in the dial or login scripts in place of the
4080 sequence, preventing the actual password from being logged.
4085 logging is in effect,
4089 for security reasons.
4091 If the first character of
4093 is an exclamation mark
4096 treats the remainder of the string as a program that must be executed
4108 it is treated as a single literal
4110 otherwise, ignoring the
4113 is parsed as a program to execute in the same was as the
4115 command above, substituting special names in the same manner.
4118 will feed the program three lines of input, each terminated by a newline
4122 The host name as sent in the CHAP challenge.
4124 The challenge string as sent in the CHAP challenge.
4130 Two lines of output are expected:
4135 to be sent with the CHAP response.
4139 which is encrypted with the challenge and request id, the answer being sent
4140 in the CHAP response packet.
4145 in this manner, it's expected that the host challenge is a series of ASCII
4146 digits or characters.
4147 An encryption device or Secure ID card is usually
4148 required to calculate the secret appropriate for the given challenge.
4149 .It set authname Ar id
4150 This sets the authentication id used in client mode PAP or CHAP negotiation.
4154 mode with CHAP enabled,
4156 is used in the initial authentication challenge and should normally be set to
4157 the local machine name.
4159 .Ar min-percent max-percent period
4161 These settings apply only in multi-link mode and default to zero, zero and
4167 mode link is available, only the first link is made active when
4169 first reads data from the tun device.
4172 link will be opened only when the current bundle throughput is at least
4174 percent of the total bundle bandwidth for
4177 When the current bundle throughput decreases to
4179 percent or less of the total bundle bandwidth for
4183 link will be brought down as long as it's not the last active link.
4185 Bundle throughput is measured as the maximum of inbound and outbound
4188 The default values cause
4190 links to simply come up one at a time.
4192 Certain devices cannot determine their physical bandwidth, so it
4193 is sometimes necessary to use the
4195 command (described below) to make
4198 .It set bandwidth Ar value
4199 This command sets the connection bandwidth in bits per second.
4201 must be greater than zero.
4202 It is currently only used by the
4205 .It set callback Ar option Ns No ...
4206 If no arguments are given, callback is disabled, otherwise,
4210 mode, will accept) one of the given
4211 .Ar option Ns No s .
4212 In client mode, if an
4216 will request a different
4218 until no options remain at which point
4220 will terminate negotiations (unless
4222 is one of the specified
4226 will accept any of the given protocols - but the client
4228 request one of them.
4229 If you wish callback to be optional, you must {include}
4235 are as follows (in this order of preference):
4238 The callee is expected to decide the callback number based on
4242 is the callee, the number should be specified as the fifth field of
4244 .Pa /etc/ppp/ppp.secret .
4246 Microsoft's callback control protocol is used.
4251 If you wish to negotiate
4253 in client mode but also wish to allow the server to request no callback at
4254 CBCP negotiation time, you must specify both
4258 as callback options.
4260 .Ar number Ns Op , Ns Ar number Ns
4263 The caller specifies the
4269 should be either a comma separated list of allowable numbers or a
4271 meaning any number is permitted.
4274 is the caller, only a single number should be specified.
4276 Note, this option is very unsafe when used with a
4278 as a malicious caller can tell
4280 to call any (possibly international) number without first authenticating
4283 If the peer does not wish to do callback at all,
4285 will accept the fact and continue without callback rather than terminating
4287 This is required (in addition to one or more other callback
4288 options) if you wish callback to be optional.
4292 .No *| Ns Ar number Ns Oo
4293 .No , Ns Ar number Ns ...\& Oc
4294 .Op Ar delay Op Ar retry
4296 If no arguments are given, CBCP (Microsoft's CallBack Control Protocol)
4297 is disabled - ie, configuring CBCP in the
4299 command will result in
4301 requesting no callback in the CBCP phase.
4304 attempts to use the given phone
4305 .Ar number Ns No (s).
4310 will insist that the client uses one of these numbers, unless
4312 is used in which case the client is expected to specify the number.
4316 will attempt to use one of the given numbers (whichever it finds to
4317 be agreeable with the peer), or if
4321 will expect the peer to specify the number.
4323 .No off| Ns Ar seconds Ns Op !\&
4327 checks for the existence of carrier depending on the type of device
4328 that has been opened:
4329 .Bl -tag -width XXX -offset XXX
4330 .It Terminal Devices
4331 Carrier is checked one second after the login script is complete.
4334 assumes that this is because the device doesn't support carrier (which
4337 NULL-modem cables), logs the fact and stops checking
4340 As ptys don't support the TIOCMGET ioctl, the tty device will switch all
4341 carrier detection off when it detects that the device is a pty.
4342 .It ISDN (i4b) Devices
4343 Carrier is checked once per second for 6 seconds.
4344 If it's not set after
4345 the sixth second, the connection attempt is considered to have failed and
4346 the device is closed.
4347 Carrier is always required for i4b devices.
4348 .It PPPoE (netgraph) Devices
4349 Carrier is checked once per second for 5 seconds.
4350 If it's not set after
4351 the fifth second, the connection attempt is considered to have failed and
4352 the device is closed.
4353 Carrier is always required for PPPoE devices.
4356 All other device types don't support carrier.
4357 Setting a carrier value will
4358 result in a warning when the device is opened.
4360 Some modems take more than one second after connecting to assert the carrier
4362 If this delay isn't increased, this will result in
4364 inability to detect when the link is dropped, as
4366 assumes that the device isn't asserting carrier.
4370 command overrides the default carrier behaviour.
4372 specifies the maximum number of seconds that
4374 should wait after the dial script has finished before deciding if
4375 carrier is available or not.
4381 will not check for carrier on the device, otherwise
4383 will not proceed to the login script until either carrier is detected
4386 has elapsed, at which point
4388 assumes that the device will not set carrier.
4390 If no arguments are given, carrier settings will go back to their default
4395 is followed immediately by an exclamation mark
4401 If carrier is not detected after
4403 seconds, the link will be disconnected.
4404 .It set choked Op Ar timeout
4405 This sets the number of seconds that
4407 will keep a choked output queue before dropping all pending output packets.
4410 is less than or equal to zero or if
4412 isn't specified, it is set to the default value of
4415 A choked output queue occurs when
4417 has read a certain number of packets from the local network for transmission,
4418 but cannot send the data due to link failure (the peer is busy etc.).
4420 will not read packets indefinitely.
4421 Instead, it reads up to
4427 packets in multi-link mode), then stops reading the network interface
4430 seconds have passed or at least one packet has been sent.
4434 seconds pass, all pending output packets are dropped.
4435 .It set ctsrts|crtscts on|off
4436 This sets hardware flow control.
4437 Hardware flow control is
4440 .It set deflate Ar out-winsize Op Ar in-winsize
4441 This sets the DEFLATE algorithms default outgoing and incoming window
4447 must be values between
4455 will insist that this window size is used and will not accept any other
4456 values from the peer.
4457 .It set dns Op Ar primary Op Ar secondary
4458 This command specifies DNS overrides for the
4463 command description above for details.
4464 This command does not affect the IP numbers requested using
4466 .It set device|line Xo
4469 This sets the device(s) to which
4471 will talk to the given
4474 All ISDN and serial device names are expected to begin with
4476 ISDN devices are usually called
4478 and serial devices are usually called
4485 it must either begin with an exclamation mark
4488 .No PPPoE: Ns Ar iface Ns Xo
4489 .Op \&: Ns Ar provider Ns
4493 enabled systems), or be of the format
4495 .Ar host : port Op /tcp|udp .
4498 If it begins with an exclamation mark, the rest of the device name is
4499 treated as a program name, and that program is executed when the device
4501 Standard input, output and error are fed back to
4503 and are read and written as if they were a regular device.
4506 .No PPPoE: Ns Ar iface Ns Xo
4507 .Op \&: Ns Ar provider Ns
4509 specification is given,
4511 will attempt to create a
4513 over Ethernet connection using the given
4521 will attempt to load it using
4523 If this fails, an external program must be used such as the
4525 program available under
4529 is passed as the service name in the PPPoE Discovery Initiation (PADI)
4531 If no provider is given, an empty value will be used.
4533 When a PPPoE connection is established,
4535 will place the name of the Access Concentrator in the environment variable
4542 for further details.
4545 .Ar host Ns No : Ns Ar port Ns Oo
4548 specification is given,
4550 will attempt to connect to the given
4558 suffix is not provided, the default is
4560 Refer to the section on
4561 .Em PPP OVER TCP and UDP
4562 above for further details.
4568 will attempt to open each one in turn until it succeeds or runs out of
4570 .It set dial Ar chat-script
4571 This specifies the chat script that will be used to dial the other
4578 and to the example configuration files for details of the chat script
4580 It is possible to specify some special
4582 in your chat script as follows:
4585 When used as the last character in a
4587 string, this indicates that a newline should not be appended.
4589 When the chat script encounters this sequence, it delays two seconds.
4591 When the chat script encounters this sequence, it delays for one quarter of
4594 This is replaced with a newline character.
4596 This is replaced with a carriage return character.
4598 This is replaced with a space character.
4600 This is replaced with a tab character.
4602 This is replaced by the current phone number (see
4606 This is replaced by the current
4612 This is replaced by the current
4619 Note that two parsers will examine these escape sequences, so in order to
4622 see the escape character, it is necessary to escape it from the
4623 .Sq command parser .
4624 This means that in practice you should use two escapes, for example:
4625 .Bd -literal -offset indent
4626 set dial "... ATDT\\\\T CONNECT"
4629 It is also possible to execute external commands from the chat script.
4630 To do this, the first character of the expect or send string is an
4633 If a literal exclamation mark is required, double it up to
4635 and it will be treated as a single literal
4637 When the command is executed, standard input and standard output are
4638 directed to the open device (see the
4640 command), and standard error is read by
4642 and substituted as the expect or send string.
4645 is running in interactive mode, file descriptor 3 is attached to
4648 For example (wrapped for readability):
4649 .Bd -literal -offset indent
4650 set login "TIMEOUT 5 \\"\\" \\"\\" login:--login: ppp \e
4651 word: ppp \\"!sh \\\\-c \\\\\\"echo \\\\-n label: >&2\\\\\\"\\" \e
4652 \\"!/bin/echo in\\" HELLO"
4655 would result in the following chat sequence (output using the
4656 .Sq set log local chat
4657 command before dialing):
4658 .Bd -literal -offset indent
4663 Chat: Expecting: login:--login:
4664 Chat: Wait for (5): login:
4666 Chat: Expecting: word:
4667 Chat: Wait for (5): word:
4669 Chat: Expecting: !sh \\-c "echo \\-n label: >&2"
4670 Chat: Exec: sh -c "echo -n label: >&2"
4671 Chat: Wait for (5): !sh \\-c "echo \\-n label: >&2" --> label:
4672 Chat: Exec: /bin/echo in
4674 Chat: Expecting: HELLO
4675 Chat: Wait for (5): HELLO
4679 Note (again) the use of the escape character, allowing many levels of
4681 Here, there are four parsers at work.
4682 The first parses the original line, reading it as three arguments.
4683 The second parses the third argument, reading it as 11 arguments.
4684 At this point, it is
4687 signs are escaped, otherwise this parser will see them as constituting
4688 an expect-send-expect sequence.
4691 character is seen, the execution parser reads the first command as three
4694 itself expands the argument after the
4696 As we wish to send the output back to the modem, in the first example
4697 we redirect our output to file descriptor 2 (stderr) so that
4699 itself sends and logs it, and in the second example, we just output to stdout,
4700 which is attached directly to the modem.
4702 This, of course means that it is possible to execute an entirely external
4704 command rather than using the internal one.
4707 for a good alternative.
4709 The external command that is executed is subjected to the same special
4710 word expansions as the
4713 .It set enddisc Op label|IP|MAC|magic|psn value
4714 This command sets our local endpoint discriminator.
4715 If set prior to LCP negotiation, and if no
4717 command has been used,
4719 will send the information to the peer using the LCP endpoint discriminator
4721 The following discriminators may be set:
4722 .Bl -tag -width indent
4724 The current label is used.
4726 Our local IP number is used.
4727 As LCP is negotiated prior to IPCP, it is
4728 possible that the IPCP layer will subsequently change this value.
4730 it does, the endpoint discriminator stays at the old value unless manually
4733 This is similar to the
4735 option above, except that the MAC address associated with the local IP
4737 If the local IP number is not resident on any Ethernet
4738 interface, the command will fail.
4740 As the local IP number defaults to whatever the machine host name is,
4742 is usually done prior to any
4746 A 20 digit random number is used.
4747 Care should be taken when using magic numbers as restarting
4749 or creating a link using a different
4751 invocation will also use a different magic number and will therefore not
4752 be recognised by the peer as belonging to the same bundle.
4753 This makes it unsuitable for
4761 should be set to an absolute public switched network number with the
4765 If no arguments are given, the endpoint discriminator is reset.
4766 .It set escape Ar value...
4767 This option is similar to the
4770 It allows the user to specify a set of characters that will be
4772 as they travel across the link.
4773 .It set filter dial|alive|in|out Ar rule-no Xo
4774 .No permit|deny|clear| Ns Ar rule-no
4777 .Ar src_addr Ns Op / Ns Ar width
4778 .Op Ar dst_addr Ns Op / Ns Ar width
4780 .Op src lt|eq|gt Ar port
4781 .Op dst lt|eq|gt Ar port
4785 .Op timeout Ar secs ]
4788 supports four filter sets.
4791 filter specifies packets that keep the connection alive - resetting the
4795 filter specifies packets that cause
4802 filter specifies packets that are allowed to travel
4803 into the machine and the
4805 filter specifies packets that are allowed out of the machine.
4807 Filtering is done prior to any IP alterations that might be done by the
4808 NAT engine on outgoing packets and after any IP alterations that might
4809 be done by the NAT engine on incoming packets.
4810 By default all empty filter sets allow all packets to pass.
4811 Rules are processed in order according to
4813 (unless skipped by specifying a rule number as the
4815 Up to 40 rules may be given for each set.
4816 If a packet doesn't match
4817 any of the rules in a given set, it is discarded.
4822 filters, this means that the packet is dropped.
4825 filters it means that the packet will not reset the idle timer (even if
4827 .Ar in Ns No / Ns Ar out
4830 value) and in the case of
4832 filters it means that the packet will not trigger a dial.
4833 A packet failing to trigger a dial will be dropped rather than queued.
4836 .Sx PACKET FILTERING
4837 above for further details.
4838 .It set hangup Ar chat-script
4839 This specifies the chat script that will be used to reset the device
4840 before it is closed.
4841 It should not normally be necessary, but can
4842 be used for devices that fail to reset themselves properly on close.
4843 .It set help|? Op Ar command
4844 This command gives a summary of available set commands, or if
4846 is specified, the command usage is shown.
4847 .It set ifaddr Oo Ar myaddr Ns
4849 .Oo Ar hisaddr Ns Op / Ns Ar \&nn
4854 This command specifies the IP addresses that will be used during
4856 Addresses are specified using the format
4862 is the preferred IP, but
4864 specifies how many bits of the address we will insist on.
4867 is omitted, it defaults to
4869 unless the IP address is 0.0.0.0 in which case it defaults to
4872 If you wish to assign a dynamic IP number to the peer,
4874 may also be specified as a range of IP numbers in the format
4875 .Bd -ragged -offset indent
4876 .Ar \&IP Ns Oo \&- Ns Ar \&IP Ns Xo
4877 .Oc Ns Oo , Ns Ar \&IP Ns
4878 .Op \&- Ns Ar \&IP Ns
4885 .Dl set ifaddr 10.0.0.1 10.0.1.2-10.0.1.10,10.0.1.20
4889 as the local IP number, but may assign any of the given 10 IP
4890 numbers to the peer.
4891 If the peer requests one of these numbers,
4892 and that number is not already in use,
4894 will grant the peers request.
4895 This is useful if the peer wants
4896 to re-establish a link using the same IP number as was previously
4897 allocated (thus maintaining any existing tcp or udp connections).
4899 If the peer requests an IP number that's either outside
4900 of this range or is already in use,
4902 will suggest a random unused IP number from the range.
4906 is specified, it is used in place of
4908 in the initial IPCP negotiation.
4909 However, only an address in the
4911 range will be accepted.
4912 This is useful when negotiating with some
4914 implementations that will not assign an IP number unless their peer
4918 It should be noted that in
4922 will configure the interface immediately upon reading the
4924 line in the config file.
4925 In any other mode, these values are just
4926 used for IPCP negotiations, and the interface isn't configured
4927 until the IPCP layer is up.
4931 argument may be overridden by the third field in the
4933 file once the client has authenticated itself
4937 .Sx AUTHENTICATING INCOMING CONNECTIONS
4938 section for details.
4940 In all cases, if the interface is already configured,
4942 will try to maintain the interface IP numbers so that any existing
4943 bound sockets will remain valid.
4944 .It set ifqueue Ar packets
4945 Set the maximum number of packets that
4947 will read from the tunnel interface while data cannot be sent to any of
4948 the available links.
4949 This queue limit is necessary to flow control outgoing data as the tunnel
4950 interface is likely to be far faster than the combined links available to
4955 is set to a value less than the number of links,
4957 will read up to that value regardless.
4958 This prevents any possible latency problems.
4960 The default value for
4964 .It set ccpretry|ccpretries Oo Ar timeout
4965 .Op Ar reqtries Op Ar trmtries
4967 .It set chapretry|chapretries Oo Ar timeout
4970 .It set ipcpretry|ipcpretries Oo Ar timeout
4971 .Op Ar reqtries Op Ar trmtries
4973 .It set ipv6cpretry|ipv6cpretries Oo Ar timeout
4974 .Op Ar reqtries Op Ar trmtries
4976 .It set lcpretry|lcpretries Oo Ar timeout
4977 .Op Ar reqtries Op Ar trmtries
4979 .It set papretry|papretries Oo Ar timeout
4982 These commands set the number of seconds that
4984 will wait before resending Finite State Machine (FSM) Request packets.
4987 for all FSMs is 3 seconds (which should suffice in most cases).
4991 is specified, it tells
4993 how many configuration request attempts it should make while receiving
4994 no reply from the peer before giving up.
4995 The default is 5 attempts for
4996 CCP, LCP and IPCP and 3 attempts for PAP and CHAP.
5000 is specified, it tells
5002 how many terminate requests should be sent before giving up waiting for the
5004 The default is 3 attempts.
5005 Authentication protocols are
5006 not terminated and it is therefore invalid to specify
5010 In order to avoid negotiations with the peer that will never converge,
5012 will only send at most 3 times the configured number of
5014 in any given negotiation session before giving up and closing that layer.
5020 This command allows the adjustment of the current log level.
5021 Refer to the Logging Facility section for further details.
5022 .It set login Ar chat-script
5025 compliments the dial-script.
5026 If both are specified, the login
5027 script will be executed after the dial script.
5028 Escape sequences available in the dial script are also available here.
5029 .It set logout Ar chat-script
5030 This specifies the chat script that will be used to logout
5031 before the hangup script is called.
5032 It should not normally be necessary.
5033 .It set lqrperiod Ar frequency
5034 This command sets the
5041 The default is 30 seconds.
5042 You must also use the
5044 command if you wish to send LQR requests to the peer.
5045 .It set mode Ar interactive|auto|ddial|background
5046 This command allows you to change the
5048 of the specified link.
5049 This is normally only useful in multi-link mode,
5050 but may also be used in uni-link mode.
5052 It is not possible to change a link that is
5057 Note: If you issue the command
5059 and have network address translation enabled, it may be useful to
5060 .Dq enable iface-alias
5064 to do the necessary address translations to enable the process that
5065 triggers the connection to connect once the link is up despite the
5066 peer assigning us a new (dynamic) IP address.
5067 .It set mppe Op 40|56|128|* Op stateless|stateful|*
5068 This option selects the encryption parameters used when negotiation
5070 MPPE can be disabled entirely with the
5073 If no arguments are given,
5075 will attempt to negotiate a stateful link with a 128 bit key, but
5076 will agree to whatever the peer requests (including no encryption
5079 If any arguments are given,
5083 on using MPPE and will close the link if it's rejected by the peer (Note;
5084 this behaviour can be overridden by a configured RADIUS server).
5086 The first argument specifies the number of bits that
5088 should insist on during negotiations and the second specifies whether
5090 should insist on stateful or stateless mode.
5091 In stateless mode, the
5092 encryption dictionary is re-initialised with every packet according to
5093 an encryption key that is changed with every packet.
5095 the encryption dictionary is re-initialised every 256 packets or after
5096 the loss of any data and the key is changed every 256 packets.
5097 Stateless mode is less efficient but is better for unreliable transport
5099 .It set mrru Op Ar value
5100 Setting this option enables Multi-link PPP negotiations, also known as
5101 Multi-link Protocol or MP.
5102 There is no default MRRU (Maximum Reconstructed Receive Unit) value.
5103 If no argument is given, multi-link mode is disabled.
5108 The default MRU (Maximum Receive Unit) is 1500.
5109 If it is increased, the other side *may* increase its MTU.
5110 In theory there is no point in decreasing the MRU to below the default as the
5112 protocol says implementations *must* be able to accept packets of at
5119 will refuse to negotiate a higher value.
5120 The maximum MRU can be set to 2048 at most.
5121 Setting a maximum of less than 1500 violates the
5123 rfc, but may sometimes be necessary.
5126 imposes a maximum of 1492 due to hardware limitations.
5128 If no argument is given, 1500 is assumed.
5129 A value must be given when
5136 The default MTU is 1500.
5137 At negotiation time,
5139 will accept whatever MRU the peer requests (assuming it's
5140 not less than 296 bytes or greater than the assigned maximum).
5143 will not accept MRU values less than
5145 When negotiations are complete, the MTU is used when writing to the
5146 interface, even if the peer requested a higher value MRU.
5147 This can be useful for
5148 limiting your packet size (giving better bandwidth sharing at the expense
5149 of more header data).
5155 will refuse to negotiate a higher value.
5156 The maximum MTU can be set to 2048 at most.
5160 is given, 1500, or whatever the peer asks for is used.
5161 A value must be given when
5164 .It set nbns Op Ar x.x.x.x Op Ar y.y.y.y
5165 This option allows the setting of the Microsoft NetBIOS name server
5166 values to be returned at the peers request.
5167 If no values are given,
5169 will reject any such requests.
5170 .It set openmode active|passive Op Ar delay
5179 will always initiate LCP/IPCP/CCP negotiation one second after the line
5181 If you want to wait for the peer to initiate negotiations, you
5184 If you want to initiate negotiations immediately or after more than one
5185 second, the appropriate
5187 may be specified here in seconds.
5188 .It set parity odd|even|none|mark
5189 This allows the line parity to be set.
5190 The default value is
5192 .It set phone Ar telno Ns Xo
5193 .Oo \&| Ns Ar backupnumber
5194 .Oc Ns ... Ns Oo : Ns Ar nextnumber
5197 This allows the specification of the phone number to be used in
5198 place of the \\\\T string in the dial and login chat scripts.
5199 Multiple phone numbers may be given separated either by a pipe
5204 Numbers after the pipe are only dialed if the dial or login
5205 script for the previous number failed.
5207 Numbers after the colon are tried sequentially, irrespective of
5208 the reason the line was dropped.
5210 If multiple numbers are given,
5212 will dial them according to these rules until a connection is made, retrying
5213 the maximum number of times specified by
5218 mode, each number is attempted at most once.
5219 .It set Op proc Ns Xo
5220 .No title Op Ar value
5222 The current process title as displayed by
5224 is changed according to
5228 is not specified, the original process title is restored.
5230 word replacements done by the shell commands (see the
5232 command above) are done here too.
5234 Note, if USER is required in the process title, the
5236 command must appear in
5238 as it is not known when the commands in
5241 .It set radius Op Ar config-file
5242 This command enables RADIUS support (if it's compiled in).
5244 refers to the radius client configuration file as described in
5246 If PAP, CHAP, MSCHAP or MSCHAPv2 are
5247 .Dq enable Ns No d ,
5250 .Em \&N Ns No etwork
5253 and uses the configured RADIUS server to authenticate rather than
5254 authenticating from the
5256 file or from the passwd database.
5258 If none of PAP, CHAP, MSCHAP or MSCHAPv2 are enabled,
5263 uses the following attributes from the RADIUS reply:
5264 .Bl -tag -width XXX -offset XXX
5265 .It RAD_FRAMED_IP_ADDRESS
5266 The peer IP address is set to the given value.
5267 .It RAD_FRAMED_IP_NETMASK
5268 The tun interface netmask is set to the given value.
5270 If the given MTU is less than the peers MRU as agreed during LCP
5271 negotiation, *and* it is less that any configured MTU (see the
5273 command), the tun interface MTU is set to the given value.
5274 .It RAD_FRAMED_COMPRESSION
5275 If the received compression type is
5278 will request VJ compression during IPCP negotiations despite any
5280 configuration command.
5282 If this attribute is supplied,
5284 will attempt to use it as an additional label to load from the
5289 The load will be attempted before (and in addition to) the normal
5291 If the label doesn't exist, no action is taken and
5293 proceeds to the normal load using the current label.
5294 .It RAD_FRAMED_ROUTE
5295 The received string is expected to be in the format
5296 .Ar dest Ns Op / Ns Ar bits
5299 Any specified metrics are ignored.
5303 are understood as valid values for
5310 to specify the default route, and
5312 is understood to be the same as
5321 For example, a returned value of
5322 .Dq 1.2.3.4/24 0.0.0.0 1 2 -1 3 400
5323 would result in a routing table entry to the 1.2.3.0/24 network via
5325 and a returned value of
5329 would result in a default route to
5332 All RADIUS routes are applied after any sticky routes are applied, making
5333 RADIUS routes override configured routes.
5334 This also applies for RADIUS routes that don't {include} the
5340 .It RAD_SESSION_TIMEOUT
5341 If supplied, the client connection is closed after the given number of
5343 .It RAD_REPLY_MESSAGE
5344 If supplied, this message is passed back to the peer as the authentication
5346 .It RAD_MICROSOFT_MS_CHAP_ERROR
5348 .Dv RAD_VENDOR_MICROSOFT
5349 vendor specific attribute is supplied, it is passed back to the peer as the
5350 authentication FAILURE text.
5351 .It RAD_MICROSOFT_MS_CHAP2_SUCCESS
5353 .Dv RAD_VENDOR_MICROSOFT
5354 vendor specific attribute is supplied and if MS-CHAPv2 authentication is
5355 being used, it is passed back to the peer as the authentication SUCCESS text.
5356 .It RAD_MICROSOFT_MS_MPPE_ENCRYPTION_POLICY
5358 .Dv RAD_VENDOR_MICROSOFT
5359 vendor specific attribute is supplied and has a value of 2 (Required),
5361 will insist that MPPE encryption is used (even if no
5363 configuration command has been given with arguments).
5364 If it is supplied with a value of 1 (Allowed), encryption is made optional
5367 configuration commands with arguments).
5368 .It RAD_MICROSOFT_MS_MPPE_ENCRYPTION_TYPES
5370 .Dv RAD_VENDOR_MICROSOFT
5371 vendor specific attribute is supplied, bits 1 and 2 are examined.
5372 If either or both are set, 40 bit and/or 128 bit (respectively) encryption
5373 options are set, overriding any given first argument to the
5376 Note, it is not currently possible for the RADIUS server to specify 56 bit
5378 .It RAD_MICROSOFT_MS_MPPE_RECV_KEY
5380 .Dv RAD_VENDOR_MICROSOFT
5381 vendor specific attribute is supplied, it's value is used as the master
5382 key for decryption of incoming data. When clients are authenticated using
5383 MSCHAPv2, the RADIUS server MUST provide this attribute if inbound MPPE is
5385 .It RAD_MICROSOFT_MS_MPPE_SEND_KEY
5387 .Dv RAD_VENDOR_MICROSOFT
5388 vendor specific attribute is supplied, it's value is used as the master
5389 key for encryption of outgoing data. When clients are authenticated using
5390 MSCHAPv2, the RADIUS server MUST provide this attribute if outbound MPPE is
5394 Values received from the RADIUS server may be viewed using
5396 .It set reconnect Ar timeout ntries
5397 Should the line drop unexpectedly (due to loss of CD or LQR
5398 failure), a connection will be re-established after the given
5400 The line will be re-connected at most
5409 will result in a variable pause, somewhere between 1 and 30 seconds.
5410 .It set recvpipe Op Ar value
5411 This sets the routing table RECVPIPE value.
5412 The optimum value is just over twice the MTU value.
5415 is unspecified or zero, the default kernel controlled value is used.
5416 .It set redial Ar secs Ns Xo
5419 .Oc Ns Op . Ns Ar next
5423 can be instructed to attempt to redial
5426 If more than one phone number is specified (see
5430 is taken before dialing each number.
5433 is taken before starting at the first number again.
5436 may be used here in place of
5440 causing a random delay of between 1 and 30 seconds.
5444 is specified, its value is added onto
5450 will only be incremented at most
5458 delay will be effective, even after
5460 has been exceeded, so an immediate manual dial may appear to have
5462 If an immediate dial is required, a
5464 should immediately follow the
5469 description above for further details.
5470 .It set sendpipe Op Ar value
5471 This sets the routing table SENDPIPE value.
5472 The optimum value is just over twice the MTU value.
5475 is unspecified or zero, the default kernel controlled value is used.
5476 .It "set server|socket" Ar TcpPort Ns No \&| Ns Xo
5477 .Ar LocalName Ns No |none|open|closed
5478 .Op password Op Ar mask
5482 to listen on the given socket or
5484 for incoming command connections.
5490 to close any existing socket and clear the socket configuration.
5495 to attempt to re-open the port.
5500 to close the open port.
5502 If you wish to specify a local domain socket,
5504 must be specified as an absolute file name, otherwise it is assumed
5505 to be the name or number of a TCP port.
5506 You may specify the octal umask to be used with a local domain socket.
5512 for details of how to translate TCP port names.
5514 You must also specify the password that must be entered by the client
5517 variable above) when connecting to this socket.
5519 specified as an empty string, no password is required for connecting clients.
5521 When specifying a local domain socket, the first
5523 sequence found in the socket name will be replaced with the current
5524 interface unit number.
5525 This is useful when you wish to use the same
5526 profile for more than one connection.
5528 In a similar manner TCP sockets may be prefixed with the
5530 character, in which case the current interface unit number is added to
5535 with a server socket, the
5537 command is the preferred mechanism of communications.
5540 can also be used, but link encryption may be implemented in the future, so
5548 interact with the diagnostic socket.
5549 .It set speed Ar value
5550 This sets the speed of the serial device.
5551 If speed is specified as
5554 treats the device as a synchronous device.
5556 Certain device types will know whether they should be specified as
5557 synchronous or asynchronous.
5558 These devices will override incorrect
5559 settings and log a warning to this effect.
5560 .It set stopped Op Ar LCPseconds Op Ar CCPseconds
5561 If this option is set,
5563 will time out after the given FSM (Finite State Machine) has been in
5564 the stopped state for the given number of
5566 This option may be useful if the peer sends a terminate request,
5567 but never actually closes the connection despite our sending a terminate
5569 This is also useful if you wish to
5570 .Dq set openmode passive
5571 and time out if the peer doesn't send a Configure Request within the
5574 .Dq set log +lcp +ccp
5577 log the appropriate state transitions.
5579 The default value is zero, where
5581 doesn't time out in the stopped state.
5583 This value should not be set to less than the openmode delay (see
5586 .It set timeout Ar idleseconds Op Ar mintimeout
5587 This command allows the setting of the idle timer.
5588 Refer to the section titled
5589 .Sx SETTING THE IDLE TIMER
5590 for further details.
5596 will never idle out before the link has been up for at least that number
5604 This command controls the ports that
5606 prioritizes when transmitting data.
5607 The default priority TCP ports
5608 are ports 21 (ftp control), 22 (ssh), 23 (telnet), 513 (login), 514 (shell),
5609 543 (klogin) and 544 (kshell).
5610 There are no priority UDP ports by default.
5625 are given, the priority port lists are cleared (although if
5629 is specified, only that list is cleared).
5632 argument is prefixed with a plus
5636 the current list is adjusted, otherwise the list is reassigned.
5638 prefixed with a plus or not prefixed at all are added to the list and
5640 prefixed with a minus are removed from the list.
5644 is specified, all priority port lists are disabled and even
5646 packets are not prioritised.
5647 .It set vj slotcomp on|off
5650 whether it should attempt to negotiate VJ slot compression.
5651 By default, slot compression is turned
5653 .It set vj slots Ar nslots
5654 This command sets the initial number of slots that
5656 will try to negotiate with the peer when VJ compression is enabled (see the
5659 It defaults to a value of 16.
5668 .It shell|! Op Ar command
5671 is not specified a shell is invoked according to the
5673 environment variable.
5674 Otherwise, the given
5677 Word replacement is done in the same way as for the
5679 command as described above.
5681 Use of the ! character
5682 requires a following space as with any of the other commands.
5683 You should note that this command is executed in the foreground;
5685 will not continue running until this process has exited.
5688 command if you wish processing to happen in the background.
5690 This command allows the user to examine the following:
5693 Show the current bundle settings.
5695 Show the current CCP compression statistics.
5697 Show the current VJ compression statistics.
5699 Show the current escape characters.
5700 .It show filter Op Ar name
5701 List the current rules for the given filter.
5704 is not specified, all filters are shown.
5706 Show the current HDLC statistics.
5708 Give a summary of available show commands.
5710 Show the current interface information
5714 Show the current IPCP statistics.
5716 Show the protocol layers currently in use.
5718 Show the current LCP statistics.
5719 .It show Op data Ns Xo
5722 Show high level link information.
5724 Show a list of available logical links.
5726 Show the current log values.
5728 Show current memory statistics.
5730 Show the current NCP statistics.
5732 Show low level link information.
5734 Show Multi-link information.
5736 Show current protocol totals.
5738 Show the current routing tables.
5740 Show the current stopped timeouts.
5742 Show the active alarm timers.
5744 Show the current version number of
5749 Go into terminal mode.
5750 Characters typed at the keyboard are sent to the device.
5751 Characters read from the device are displayed on the screen.
5756 automatically enables Packet Mode and goes back into command mode.
5761 Read the example configuration files.
5762 They are a good source of information.
5771 to get online information about what's available.
5773 The following URLs contain useful information:
5774 .Bl -bullet -compact
5776 .Pa http://wiki.dragonflybsd.org/index.cgi/userppp.html
5781 refers to four files:
5787 These files are placed in the
5791 .It Pa /etc/ppp/ppp.conf
5792 System default configuration file.
5793 .It Pa /etc/ppp/ppp.secret
5794 An authorisation file for each system.
5795 .It Pa /etc/ppp/ppp.linkup
5796 A file to check when
5798 establishes a network level connection.
5799 .It Pa /etc/ppp/ppp.linkdown
5800 A file to check when
5802 closes a network level connection.
5803 .It Pa /var/log/ppp.log
5804 Logging and debugging information file.
5805 Note, this name is specified in
5806 .Pa /etc/syslog.conf .
5809 for further details.
5810 .It Pa /var/spool/lock/LCK..*
5811 tty port locking file.
5814 for further details.
5815 .It Pa /var/run/tunN.pid
5816 The process id (pid) of the
5818 program connected to the tunN device, where
5820 is the number of the device.
5821 .It Pa /var/run/ttyXX.if
5822 The tun interface used by this port.
5823 Again, this file is only created in
5829 .It Pa /etc/services
5830 Get port number if port number is using service name.
5831 .It Pa /var/run/ppp-authname-class-value
5832 In multi-link mode, local domain sockets are created using the peer
5835 the peer endpoint discriminator class
5837 and the peer endpoint discriminator value
5839 As the endpoint discriminator value may be a binary value, it is turned
5840 to HEX to determine the actual file name.
5842 This socket is used to pass links between different instances of
5854 ifdef({LOCALNAT},{},{.Xr libalias 3 ,
5856 ifdef({LOCALRAD},{},{.Xr libradius 3 ,
5886 This program was originally written by
5887 .An Toshiharu OHNO Aq tony-o@iij.ad.jp ,
5888 and was submitted to
5891 .An Atsushi Murai Aq amurai@spec.co.jp .
5893 It was substantially modified during 1997 by
5894 .An Brian Somers Aq brian@Awfulhak.org ,
5897 in November that year
5898 (just after the 2.2 release).
5900 Most of the code was rewritten by
5902 in early 1998 when multi-link ppp support was added.
projects / dragonfly.git / blob