2 .\" Copyright (c) 2001 Brian Somers <brian@Awfulhak.org>
3 .\" All rights reserved.
5 .\" Redistribution and use in source and binary forms, with or without
6 .\" modification, are permitted provided that the following conditions
8 .\" 1. Redistributions of source code must retain the above copyright
9 .\" notice, this list of conditions and the following disclaimer.
10 .\" 2. Redistributions in binary form must reproduce the above copyright
11 .\" notice, this list of conditions and the following disclaimer in the
12 .\" documentation and/or other materials provided with the distribution.
14 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 .Nd Point to Point Protocol (a.k.a. user-ppp)
42 This is a user process
47 is implemented as a part of the kernel (e.g., as managed by
49 and it is thus somewhat hard to debug and/or modify its behaviour.
50 However, in this implementation
52 is done as a user process with the help of the
53 tunnel device driver (tun).
57 flag does the equivalent of a
61 network address translation features.
64 to act as a NAT or masquerading engine for all machines on an internal
68 for details on the technical side of the NAT engine.
70 .Sx NETWORK ADDRESS TRANSLATION (PACKET ALIASING)
71 section of this manual page for details on how to configure NAT in
78 to be silent at startup rather than displaying the mode and interface
85 to only attempt to open
86 .Pa /dev/tun Ns Ar N .
89 will start with a value of 0 for
91 and keep trying to open a tunnel device by incrementing the value of
93 by one each time until it succeeds.
94 If it fails three times in a row
95 because the device file is missing, it gives up.
101 .Bl -tag -width XXX -offset XXX
104 opens the tun interface, configures it then goes into the background.
105 The link is not brought up until outgoing data is detected on the tun
106 interface at which point
108 attempts to bring up the link.
109 Packets received (including the first one) while
111 is trying to bring the link up will remain queued for a default of
121 must be given on the command line (see below) and a
123 must be done in the system profile that specifies a peer IP address to
124 use when configuring the interface.
127 is usually appropriate.
131 .Pa /usr/share/examples/ppp/ppp.conf.sample
136 attempts to establish a connection with the peer immediately.
139 goes into the background and the parent process returns an exit code
143 exits with a non-zero result.
147 attempts to establish a connection with the peer immediately, but never
149 The link is created in background mode.
150 This is useful if you wish to control
152 invocation from another process.
154 This is used for communicating over an already established connection,
155 usually when receiving incoming connections accepted by
160 line and uses descriptor 0 as the link.
162 will also ignore any configured chat scripts unless the
164 option has been enabled.
166 If callback is configured,
170 information when dialing back.
176 will behave slightly differently if descriptor 0 was created by
178 As pipes are not bi-directional, ppp will redirect all writes to descriptor
179 1 (standard output), leaving only reads acting on descriptor 0.
180 No special action is taken if descriptor 0 was created by
183 This option is designed for machines connected with a dedicated
186 will always keep the device open and will ignore any configured
187 chat scripts unless the
189 option has been enabled.
191 This mode is equivalent to
195 will bring the link back up any time it is dropped for any reason.
197 This is a no-op, and gives the same behaviour as if none of the above
198 modes have been specified.
200 loads any sections specified on the command line then provides an
204 One or more configuration entries or systems
206 .Pa /etc/ppp/ppp.conf )
207 may also be specified on the command line.
212 .Pa /etc/ppp/ppp.conf
213 at startup, followed by each of the systems specified on the command line.
216 .It Provides an interactive user interface.
217 Using its command mode, the user can
218 easily enter commands to establish the connection with the remote end, check
219 the status of connection and close the connection.
220 All functions can also be optionally password protected for security.
221 .It Supports both manual and automatic dialing.
222 Interactive mode has a
224 command which enables you to talk to the device directly.
225 When you are connected to the remote peer and it starts to talk
228 detects it and switches to packet mode automatically.
230 determined the proper sequence for connecting with the remote host, you
231 can write a chat script to {define} the necessary dialing and login
232 procedure for later convenience.
233 .It Supports on-demand dialup capability.
238 will act as a daemon and wait for a packet to be sent over the
241 When this happens, the daemon automatically dials and establishes the
243 In almost the same manner
245 mode (direct-dial mode) also automatically dials and establishes the
247 However, it differs in that it will dial the remote site
248 any time it detects the link is down, even if there are no packets to be
250 This mode is useful for full-time connections where we worry less
251 about line charges and more about being connected full time.
254 mode is also available.
255 This mode is targeted at a dedicated link between two machines.
257 will never voluntarily quit from dedicated mode - you must send it the
259 command via its diagnostic socket.
262 will force an LCP renegotiation, and a
264 will force it to exit.
265 .It Supports client callback.
267 can use either the standard LCP callback protocol or the Microsoft
268 CallBack Control Protocol (ftp://ftp.microsoft.com/developr/rfc/cbcp.txt).
269 .It Supports NAT or packet aliasing.
270 Packet aliasing (a.k.a.\& IP masquerading) allows computers on a
271 private, unregistered network to access the Internet.
274 host acts as a masquerading gateway.
275 IP addresses as well as TCP and
276 UDP port numbers are NAT'd for outgoing packets and de-NAT'd for
278 .It Supports background PPP connections.
279 In background mode, if
281 successfully establishes the connection, it will become a daemon.
282 Otherwise, it will exit with an error.
283 This allows the setup of
284 scripts that wish to execute certain commands only if the connection
285 is successfully established.
286 .It Supports server-side PPP connections.
289 acts as server which accepts incoming
291 connections on stdin/stdout.
292 .It Supports PAP and CHAP (rfc 1994, 2433 and 2759) authentication.
293 With PAP or CHAP, it is possible to skip the Unix style
295 procedure, and use the
297 protocol for authentication instead.
298 If the peer requests Microsoft CHAP authentication and
300 is compiled with DES support, an appropriate MD4/DES response will be
302 .It Supports RADIUS (rfc 2138 & 2548) authentication.
303 An extension to PAP and CHAP,
310 allows authentication information to be stored in a central or
311 distributed database along with various per-user framed connection
315 is available at compile time,
319 requests when configured to do so.
320 .It Supports Proxy Arp.
322 can be configured to make one or more proxy arp entries on behalf of
324 This allows routing from the peer to the LAN without
325 configuring each machine on that LAN.
326 .It Supports packet filtering.
327 User can {define} four kinds of filters: the
329 filter for incoming packets, the
331 filter for outgoing packets, the
333 filter to {define} a dialing trigger packet and the
335 filter for keeping a connection alive with the trigger packet.
336 .It Tunnel driver supports bpf.
339 to check the packet flow over the
342 .It Supports PPP over TCP and PPP over UDP.
343 If a device name is specified as
344 .Em host Ns No : Ns Em port Ns
349 will open a TCP or UDP connection for transporting data rather than using a
350 conventional serial device.
351 UDP connections force
353 into synchronous mode.
354 .It Supports PPP over Ethernet (rfc 2516).
357 is given a device specification of the format
358 .No PPPoE: Ns Ar iface Ns Xo
359 .Op \&: Ns Ar provider Ns
373 On systems that do not support
375 an external program such as
378 .It "Supports IETF draft Predictor-1 (rfc 1978) and DEFLATE (rfc 1979) compression."
380 supports not only VJ-compression but also Predictor-1 and DEFLATE compression.
381 Normally, a modem has built-in compression (e.g., v42.bis) and the system
382 may receive higher data rates from it as a result of such compression.
383 While this is generally a good thing in most other situations, this
384 higher speed data imposes a penalty on the system by increasing the
385 number of serial interrupts the system has to process in talking to the
386 modem and also increases latency.
387 Unlike VJ-compression, Predictor-1 and DEFLATE compression pre-compresses
389 network traffic flowing through the link, thus reducing overheads to a
391 .It Supports Microsoft's IPCP extensions (rfc 1877).
392 Name Server Addresses and NetBIOS Name Server Addresses can be negotiated
393 with clients using the Microsoft
395 stack (i.e., Win95, WinNT)
396 .It Supports Multi-link PPP (rfc 1990)
397 It is possible to configure
399 to open more than one physical connection to the peer, combining the
400 bandwidth of all links for better throughput.
401 .It Supports MPPE (draft-ietf-pppext-mppe)
402 MPPE is Microsoft Point to Point Encryption scheme.
403 It is possible to configure
405 to participate in Microsoft's Windows VPN.
408 can only get encryption keys from CHAP 81 authentication.
410 must be compiled with DES for MPPE to operate.
411 .It Supports IPV6CP (rfc 2023).
412 An IPv6 connection can be made in addition to or instead of the normal
425 will not run if the invoking user id is not zero.
426 This may be overridden by using the
429 .Pa /etc/ppp/ppp.conf .
430 When running as a normal user,
432 switches to user id 0 in order to alter the system routing table, set up
433 system lock files and read the ppp configuration files.
434 All external commands (executed via the "shell" or "!bg" commands) are executed
435 as the user id that invoked
439 logging facility if you are interested in what exactly is done as user id
444 you may need to deal with some initial configuration details.
447 Make sure that your system has a group named
451 file and that the group contains the names of all users expected to use
455 manual page for details.
456 Each of these users must also be given access using the
459 .Pa /etc/ppp/ppp.conf .
466 A common log file name is
467 .Pa /var/log/ppp.log .
468 To make output go to this file, put the following lines in the
471 .Bd -literal -offset indent
473 *.*<TAB>/var/log/ppp.log
476 It is possible to have more than one
478 log file by creating a link to the
486 .Bd -literal -offset indent
488 *.*<TAB>/var/log/ppp0.log
492 .Pa /etc/syslog.conf .
493 Do not forget to send a
498 .Pa /etc/syslog.conf .
500 Although not strictly relevant to
502 operation, you should configure your resolver so that it works correctly.
503 This can be done by configuring a local DNS
506 or by adding the correct
509 .Pa /etc/resolv.conf .
512 manual page for details.
514 Alternatively, if the peer supports it,
516 can be configured to ask the peer for the nameserver address(es) and to
524 commands below for details.
527 In the following examples, we assume that your machine name is
533 above) with no arguments, you are presented with a prompt:
534 .Bd -literal -offset indent
540 part of your prompt should always be in upper case.
541 If it is in lower case, it means that you must supply a password using the
544 This only ever happens if you connect to a running version of
546 and have not authenticated yourself using the correct password.
548 You can start by specifying the device name and speed:
549 .Bd -literal -offset indent
550 ppp ON awfulhak> set device /dev/cuau0
551 ppp ON awfulhak> set speed 38400
554 Normally, hardware flow control (CTS/RTS) is used.
556 certain circumstances (as may happen when you are connected directly
557 to certain PPP-capable terminal servers), this may result in
559 hanging as soon as it tries to write data to your communications link
560 as it is waiting for the CTS (clear to send) signal - which will never
562 Thus, if you have a direct line and cannot seem to make a
563 connection, try turning CTS/RTS off with
565 If you need to do this, check the
567 description below too - you will probably need to
568 .Dq set accmap 000a0000 .
570 Usually, parity is set to
575 Parity is a rather archaic error checking mechanism that is no
576 longer used because modern modems do their own error checking, and most
577 link-layer protocols (that is what
579 is) use much more reliable checking mechanisms.
580 Parity has a relatively
581 huge overhead (a 12.5% increase in traffic) and as a result, it is always
588 However, some ISPs (Internet Service Providers) may use
589 specific parity settings at connection time (before
592 Notably, Compuserve insist on even parity when logging in:
593 .Bd -literal -offset indent
594 ppp ON awfulhak> set parity even
597 You can now see what your current device settings look like:
598 .Bd -literal -offset indent
599 ppp ON awfulhak> show physical
603 Link Type: interactive
609 Device List: /dev/cuau0
610 Characteristics: 38400bps, cs8, even parity, CTS/RTS on
613 0 octets in, 0 octets out
618 The term command can now be used to talk directly to the device:
619 .Bd -literal -offset indent
620 ppp ON awfulhak> term
626 Password: myisppassword
630 When the peer starts to talk in
633 detects this automatically and returns to command mode.
634 .Bd -literal -offset indent
635 ppp ON awfulhak> # No link has been established
636 Ppp ON awfulhak> # We've connected & finished LCP
637 PPp ON awfulhak> # We've authenticated
638 PPP ON awfulhak> # We've agreed IP numbers
641 If it does not, it is probable that the peer is waiting for your end to
647 configuration packets to the peer, use the
649 command to drop out of terminal mode and enter packet mode.
651 If you never even receive a login prompt, it is quite likely that the
652 peer wants to use PAP or CHAP authentication instead of using Unix-style
653 login/password authentication.
654 To set things up properly, drop back to
655 the prompt and set your authentication name and key, then reconnect:
656 .Bd -literal -offset indent
658 ppp ON awfulhak> set authname myispusername
659 ppp ON awfulhak> set authkey myisppassword
660 ppp ON awfulhak> term
667 You may need to tell ppp to initiate negotiations with the peer here too:
668 .Bd -literal -offset indent
670 ppp ON awfulhak> # No link has been established
671 Ppp ON awfulhak> # We've connected & finished LCP
672 PPp ON awfulhak> # We've authenticated
673 PPP ON awfulhak> # We've agreed IP numbers
676 You are now connected!
679 in the prompt has changed to capital letters to indicate that you have
681 If only some of the three Ps go uppercase, wait until
682 either everything is uppercase or lowercase.
683 If they revert to lowercase, it means that
685 could not successfully negotiate with the peer.
686 A good first step for troubleshooting at this point would be to
687 .Bd -literal -offset indent
688 ppp ON awfulhak> set log local phase lcp ipcp
694 command description below for further details.
695 If things fail at this point,
696 it is quite important that you turn logging on and try again.
698 important that you note any prompt changes and report them to anyone trying
701 When the link is established, the show command can be used to see how
703 .Bd -literal -offset indent
704 PPP ON awfulhak> show physical
705 * Modem related information is shown here *
706 PPP ON awfulhak> show ccp
707 * CCP (compression) related information is shown here *
708 PPP ON awfulhak> show lcp
709 * LCP (line control) related information is shown here *
710 PPP ON awfulhak> show ipcp
711 * IPCP (IP) related information is shown here *
712 PPP ON awfulhak> show ipv6cp
713 * IPV6CP (IPv6) related information is shown here *
714 PPP ON awfulhak> show link
715 * Link (high level) related information is shown here *
716 PPP ON awfulhak> show bundle
717 * Logical (high level) connection related information is shown here *
720 At this point, your machine has a host route to the peer.
722 that you can only make a connection with the host on the other side
724 If you want to add a default route entry (telling your
725 machine to send all packets without another routing entry to the other
728 link), enter the following command:
729 .Bd -literal -offset indent
730 PPP ON awfulhak> add default HISADDR
735 represents the IP address of the connected peer.
738 command fails due to an existing route, you can overwrite the existing
740 .Bd -literal -offset indent
741 PPP ON awfulhak> add! default HISADDR
744 This command can also be executed before actually making the connection.
745 If a new IP address is negotiated at connection time,
747 will update your default route accordingly.
749 You can now use your network applications (ping, telnet, ftp, etc.)
750 in other windows or terminals on your machine.
751 If you wish to reuse the current terminal, you can put
753 into the background using your standard shell suspend and background
761 section for details on all available commands.
762 .Sh AUTOMATIC DIALING
763 To use automatic dialing, you must prepare some Dial and Login chat scripts.
764 See the example definitions in
765 .Pa /usr/share/examples/ppp/ppp.conf.sample
767 .Pa /etc/ppp/ppp.conf
769 Each line contains one comment, inclusion, label or command:
772 A line starting with a
774 character is treated as a comment line.
775 Leading whitespace are ignored when identifying comment lines.
777 An inclusion is a line beginning with the word
779 It must have one argument - the file to {include}.
781 .Dq {!include} ~/.ppp.conf
782 for compatibility with older versions of
785 A label name starts in the first column and is followed by
789 A command line must contain a space or tab in the first column.
791 A string starting with the
793 character is substituted with the value of the environment variable by
795 Likewise, a string starting with the
797 character is substituted with the full path to the home directory of
798 the user account by the same name, and the
800 character by itself is substituted with the full path to the home directory
802 If you want to include a literal
806 character in a command or argument, enclose them in double quotes, e.g.,
807 .Bd -literal -offset indent
808 set password "pa$ss~word"
813 .Pa /etc/ppp/ppp.conf
814 file should consist of at least a
817 This section is always executed.
818 It should also contain
819 one or more sections, named according to their purpose, for example,
821 would represent your ISP, and
823 would represent an incoming
826 You can now specify the destination label name when you invoke
828 Commands associated with the
830 label are executed, followed by those associated with the destination
834 is started with no arguments, the
836 section is still executed.
837 The load command can be used to manually load a section from the
838 .Pa /etc/ppp/ppp.conf
840 .Bd -literal -offset indent
841 ppp ON awfulhak> load MyISP
844 Note, no action is taken by
846 after a section is loaded, whether it is the result of passing a label on
847 the command line or using the
850 Only the commands specified for that label in the configuration
852 However, when invoking
859 switches, the link mode tells
861 to establish a connection.
864 command below for further details.
866 Once the connection is made, the
868 portion of the prompt will change to
870 .Bd -literal -offset indent
873 ppp ON awfulhak> dial
879 The Ppp prompt indicates that
881 has entered the authentication phase.
882 The PPp prompt indicates that
884 has entered the network phase.
885 The PPP prompt indicates that
887 has successfully negotiated a network layer protocol and is in
891 .Pa /etc/ppp/ppp.linkup
892 file is available, its contents are executed
895 connection is established.
899 .Pa /usr/share/examples/ppp/ppp.conf.sample
900 which runs a script in the background after the connection is established
905 commands below for a description of possible substitution strings).
906 Similarly, when a connection is closed, the contents of the
907 .Pa /etc/ppp/ppp.linkdown
909 Both of these files have the same format as
910 .Pa /etc/ppp/ppp.conf .
912 In previous versions of
914 it was necessary to re-add routes such as the default route in the
920 where all routes that contain the
926 literals will automatically be updated when the values of these variables
928 .Sh BACKGROUND DIALING
929 If you want to establish a connection using
931 non-interactively (such as from a
935 job) you should use the
942 attempts to establish the connection immediately.
944 numbers are specified, each phone number will be tried once.
945 If the attempt fails,
947 exits immediately with a non-zero exit code.
950 becomes a daemon, and returns an exit status of zero to its caller.
951 The daemon exits automatically if the connection is dropped by the
952 remote system, or it receives a
956 Demand dialing is enabled with the
961 You must also specify the destination label in
962 .Pa /etc/ppp/ppp.conf
966 command to {define} the remote peers IP address.
968 .Pa /usr/share/examples/ppp/ppp.conf.sample )
969 .Bd -literal -offset indent
979 runs as a daemon but you can still configure or examine its
980 configuration by using the
983 .Pa /etc/ppp/ppp.conf ,
985 .Dq Li "set server +3000 mypasswd" )
986 and connecting to the diagnostic port as follows:
987 .Bd -literal -offset indent
988 # pppctl 3000 (assuming tun0)
990 PPP ON awfulhak> show who
991 tcp (127.0.0.1:1028) *
996 command lists users that are currently connected to
999 If the diagnostic socket is closed or changed to a different
1000 socket, all connections are immediately dropped.
1004 mode, when an outgoing packet is detected,
1006 will perform the dialing action (chat script) and try to connect
1010 mode, the dialing action is performed any time the line is found
1012 If the connect fails, the default behaviour is to wait 30 seconds
1013 and then attempt to connect when another outgoing packet is detected.
1014 This behaviour can be changed using the
1018 .No set redial Ar secs Ns
1020 .Oo - Ns Ar max Ns Oc Oc Ns
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)
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 Do not 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/cuau1
1216 ppp ON awfulhak> set speed 38400
1217 ppp ON awfulhak> term
1218 deflink: Entering terminal mode on /dev/cuau1
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 does not 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 Do not forget to send a
1456 after you have 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 will 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 are enabling PAP, you will 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 are 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 have 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 is 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 is 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 will not 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 would like to use 192.244.177.38 as my address if it is possible, but I will
1993 also accept any IP address between 192.244.177.0 and 192.244.177.255.
1995 I would like to make him use 192.244.177.2 as his own address, but I will 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 will accept/permit any IP address but I will
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
2027 .Oo \&| Ns Ar backupnumber Oc Ns ... Ns Oo : Ns Ar nextnumber Oc Ns ...
2030 Numbers after the first in a pipe-separated list are only used if the
2031 previous number was used in a failed dial or login script.
2033 separated by a colon are used sequentially, irrespective of what happened
2034 as a result of using the previous number.
2036 .Bd -literal -offset indent
2037 set phone "1234567|2345678:3456789|4567890"
2040 Here, the 1234567 number is attempted.
2041 If the dial or login script fails,
2042 the 2345678 number is used next time, but *only* if the dial or login script
2044 On the dial after this, the 3456789 number is used.
2046 number is only used if the dial or login script using the 3456789 fails.
2047 If the login script of the 2345678 number fails, the next number is still the
2049 As many pipes and colons can be used as are necessary
2050 (although a given site would usually prefer to use either the pipe or the
2051 colon, but not both).
2052 The next number redial timeout is used between all numbers.
2053 When the end of the list is reached, the normal redial period is
2054 used before starting at the beginning again.
2055 The selected phone number is substituted for the \\\\T string in the
2057 command (see below).
2059 Set up your redial requirements using
2061 For example, if you have a bad telephone line or your provider is
2062 usually engaged (not so common these days), you may want to specify
2064 .Bd -literal -offset indent
2068 This says that up to 4 phone calls should be attempted with a pause of 10
2069 seconds before dialing the first number again.
2071 Describe your login procedure using the
2078 command is used to talk to your modem and establish a link with your
2080 .Bd -literal -offset indent
2081 set dial "ABORT BUSY ABORT NO\\\\sCARRIER TIMEOUT 4 \\"\\" \e
2082 ATZ OK-ATZ-OK ATDT\\\\T TIMEOUT 60 CONNECT"
2085 This modem "chat" string means:
2088 Abort if the string "BUSY" or "NO CARRIER" are received.
2090 Set the timeout to 4 seconds.
2097 If that is not received within the 4 second timeout, send ATZ
2100 Send ATDTxxxxxxx where xxxxxxx is the next number in the phone list from
2103 Set the timeout to 60.
2105 Wait for the CONNECT string.
2108 Once the connection is established, the login script is executed.
2109 This script is written in the same style as the dial script, but care should
2110 be taken to avoid having your password logged:
2111 .Bd -literal -offset indent
2112 set authkey MySecret
2113 set login "TIMEOUT 15 login:-\\\\r-login: awfulhak \e
2114 word: \\\\P ocol: PPP HELLO"
2117 This login "chat" string means:
2120 Set the timeout to 15 seconds.
2123 If it is not received, send a carriage return and expect
2128 Expect "word:" (the tail end of a "Password:" prompt).
2130 Send whatever our current
2134 Expect "ocol:" (the tail end of a "Protocol:" prompt).
2143 command is logged specially.
2148 logging is enabled, the actual password is not logged;
2152 Login scripts vary greatly between ISPs.
2153 If you are setting one up for the first time,
2154 .Em ENABLE CHAT LOGGING
2155 so that you can see if your script is behaving as you expect.
2161 to specify your serial line and speed, for example:
2162 .Bd -literal -offset indent
2163 set device /dev/cuau0
2167 Cuad0 is the first serial port on
2174 A speed of 115200 should be specified
2175 if you have a modem capable of bit rates of 28800 or more.
2176 In general, the serial speed should be about four times the modem speed.
2180 command to {define} the IP address.
2183 If you know what IP address your provider uses, then use it as the remote
2184 address (dst_addr), otherwise choose something like 10.0.0.2/0 (see below).
2186 If your provider has assigned a particular IP address to you, then use
2187 it as your address (src_addr).
2189 If your provider assigns your address dynamically, choose a suitably
2190 unobtrusive and unspecific IP number as your address.
2191 10.0.0.1/0 would be appropriate.
2192 The bit after the / specifies how many bits of the
2193 address you consider to be important, so if you wanted to insist on
2194 something in the class C network 1.2.3.0, you could specify 1.2.3.1/24.
2196 If you find that your ISP accepts the first IP number that you suggest,
2197 specify third and forth arguments of
2199 This will force your ISP to assign a number.
2200 (The third argument will
2201 be ignored as it is less restrictive than the default mask for your
2205 An example for a connection where you do not know your IP number or your
2206 ISPs IP number would be:
2207 .Bd -literal -offset indent
2208 set ifaddr 10.0.0.1/0 10.0.0.2/0 0.0.0.0 0.0.0.0
2212 In most cases, your ISP will also be your default router.
2213 If this is the case, add the line
2214 .Bd -literal -offset indent
2219 .Pa /etc/ppp/ppp.conf
2221 .Pa /etc/ppp/ppp.linkup
2222 for setups that do not use
2228 to add a default route to whatever the peer address is
2229 (10.0.0.2 in this example).
2232 meaning that should the value of
2234 change, the route will be updated accordingly.
2236 If your provider requests that you use PAP/CHAP authentication methods, add
2237 the next lines to your
2238 .Pa /etc/ppp/ppp.conf
2240 .Bd -literal -offset indent
2242 set authkey MyPassword
2245 Both are accepted by default, so
2247 will provide whatever your ISP requires.
2249 It should be noted that a login script is rarely (if ever) required
2250 when PAP or CHAP are in use.
2252 Ask your ISP to authenticate your nameserver address(es) with the line
2253 .Bd -literal -offset indent
2259 do this if you are running a local DNS unless you also either use
2264 .Pa /etc/ppp/ppp.linkdown ,
2267 will simply circumvent its use by entering some nameserver lines in
2268 .Pa /etc/resolv.conf .
2272 .Pa /usr/share/examples/ppp/ppp.conf.sample
2274 .Pa /usr/share/examples/ppp/ppp.linkup.sample
2275 for some real examples.
2276 The pmdemand label should be appropriate for most ISPs.
2277 .Sh LOGGING FACILITY
2279 is able to generate the following log info either via
2281 or directly to the screen:
2283 .Bl -tag -width XXXXXXXXX -offset XXX -compact
2285 Enable all logging facilities.
2286 This generates a lot of log.
2287 The most common use of 'all' is as a basis, where you remove some facilities
2288 after enabling 'all' ('debug' and 'timer' are usually best disabled.)
2290 Dump async level packet in hex.
2292 Generate CBCP (CallBack Control Protocol) logs.
2294 Generate a CCP packet trace.
2302 chat script trace logs.
2304 Log commands executed either from the command line or any of the configuration
2307 Log Chat lines containing the string "CONNECT".
2309 Log debug information.
2311 Log DNS QUERY packets.
2313 Log packets permitted by the dial filter and denied by any filter.
2315 Dump HDLC packet in hex.
2317 Log all function calls specifically made as user id 0.
2319 Generate an IPCP packet trace.
2321 Generate an LCP packet trace.
2323 Generate LQR reports.
2325 Phase transition log output.
2327 Dump physical level packet in hex.
2329 Dump RADIUS information.
2330 RADIUS information resulting from the link coming up or down is logged at
2335 This log level is most useful for monitoring RADIUS alive information.
2337 Dump sync level packet in hex.
2339 Dump all TCP/IP packets.
2341 Log timer manipulation.
2343 Include the tun device on each log line.
2345 Output to the terminal device.
2346 If there is currently no terminal,
2347 output is sent to the log file using syslogs
2350 Output to both the terminal device
2351 and the log file using syslogs
2354 Output to the log file using
2360 command allows you to set the logging output level.
2361 Multiple levels can be specified on a single command line.
2362 The default is equivalent to
2365 It is also possible to log directly to the screen.
2366 The syntax is the same except that the word
2368 should immediately follow
2372 (i.e., only the un-maskable warning, error and alert output).
2374 If The first argument to
2375 .Dq set log Op local
2380 character, the current log levels are
2381 not cleared, for example:
2382 .Bd -literal -offset indent
2383 PPP ON awfulhak> set log phase
2384 PPP ON awfulhak> show log
2385 Log: Phase Warning Error Alert
2386 Local: Warning Error Alert
2387 PPP ON awfulhak> set log +tcp/ip -warning
2388 PPP ON awfulhak> set log local +command
2389 PPP ON awfulhak> show log
2390 Log: Phase TCP/IP Warning Error Alert
2391 Local: Command Warning Error Alert
2394 Log messages of level Warning, Error and Alert are not controllable
2396 .Dq set log Op local .
2400 level is special in that it will not be logged if it can be displayed
2404 deals with the following signals:
2405 .Bl -tag -width "USR2"
2407 Receipt of this signal causes the termination of the current connection
2411 to exit unless it is in
2416 .It HUP, TERM & QUIT
2423 to re-open any existing server socket, dropping all existing diagnostic
2425 Sockets that could not previously be opened will be retried.
2429 to close any existing server socket, dropping all existing diagnostic
2432 can still be used to re-open the socket.
2435 If you wish to use more than one physical link to connect to a
2437 peer, that peer must also understand the
2440 Refer to RFC 1990 for specification details.
2442 The peer is identified using a combination of his
2443 .Dq endpoint discriminator
2445 .Dq authentication id .
2446 Either or both of these may be specified.
2447 It is recommended that
2448 at least one is specified, otherwise there is no way of ensuring that
2449 all links are actually connected to the same peer program, and some
2450 confusing lock-ups may result.
2451 Locally, these identification variables are specified using the
2460 must be agreed in advance with the peer.
2462 Multi-link capabilities are enabled using the
2464 command (set maximum reconstructed receive unit).
2465 Once multi-link is enabled,
2467 will attempt to negotiate a multi-link connection with the peer.
2469 By default, only one
2474 To create more links, the
2477 This command will clone existing links, where all
2478 characteristics are the same except:
2481 The new link has its own name as specified on the
2488 Its mode may subsequently be changed using the
2492 The new link is in a
2497 A summary of all available links can be seen using the
2501 Once a new link has been created, command usage varies.
2502 All link specific commands must be prefixed with the
2504 command, specifying on which link the command is to be applied.
2505 When only a single link is available,
2507 is smart enough not to require the
2511 Some commands can still be used without specifying a link - resulting
2512 in an operation at the
2515 For example, once two or more links are available, the command
2517 will show CCP configuration and statistics at the multi-link level, and
2518 .Dq link deflink show ccp
2519 will show the same information at the
2523 Armed with this information, the following configuration might be used:
2524 .Bd -literal -offset indent
2528 set device /dev/cuau0 /dev/cuau1 /dev/cuau2
2529 set phone "123456789"
2530 set dial "ABORT BUSY ABORT NO\\sCARRIER TIMEOUT 5 \\"\\" ATZ \e
2531 OK-AT-OK \\\\dATDT\\\\T TIMEOUT 45 CONNECT"
2533 set ifaddr 10.0.0.1/0 10.0.0.2/0 0.0.0.0 0.0.0.0
2535 set authkey ppppassword
2538 clone 1,2,3 # Create 3 new links - duplicates of the default
2539 link deflink remove # Delete the default link (called ``deflink'')
2542 Note how all cloning is done at the end of the configuration.
2543 Usually, the link will be configured first, then cloned.
2544 If you wish all links
2545 to be up all the time, you can add the following line to the end of your
2547 .Bd -literal -offset indent
2548 link 1,2,3 set mode ddial
2551 If you want the links to dial on demand, this command could be used:
2552 .Bd -literal -offset indent
2553 link * set mode auto
2556 Links may be tied to specific names by removing the
2558 line above, and specifying the following after the
2561 .Bd -literal -offset indent
2562 link 1 set device /dev/cuau0
2563 link 2 set device /dev/cuau1
2564 link 3 set device /dev/cuau2
2569 command to see which commands require context (using the
2571 command), which have optional
2572 context and which should not have any context.
2578 mode with the peer, it creates a local domain socket in the
2581 This socket is used to pass link information (including
2582 the actual link file descriptor) between different
2587 ability to be run from a
2593 capability), without needing to have initial control of the serial
2597 negotiates multi-link mode, it will pass its open link to any
2598 already running process.
2599 If there is no already running process,
2601 will act as the master, creating the socket and listening for new
2603 .Sh PPP COMMAND LIST
2604 This section lists the available commands and their effect.
2605 They are usable either from an interactive
2607 session, from a configuration file or from a
2613 .It accept|deny|enable|disable Ar option....
2614 These directives tell
2616 how to negotiate the initial connection with the peer.
2619 has a default of either accept or deny and enable or disable.
2621 means that the option will be ACK'd if the peer asks for it.
2623 means that the option will be NAK'd if the peer asks for it.
2625 means that the option will be requested by us.
2627 means that the option will not be requested by us.
2630 may be one of the following:
2633 Default: Enabled and Accepted.
2634 ACFComp stands for Address and Control Field Compression.
2635 Non LCP packets will usually have an address
2636 field of 0xff (the All-Stations address) and a control field of
2637 0x03 (the Unnumbered Information command).
2639 negotiated, these two bytes are simply not sent, thus minimising
2646 Default: Disabled and Accepted.
2647 CHAP stands for Challenge Handshake Authentication Protocol.
2648 Only one of CHAP and PAP (below) may be negotiated.
2649 With CHAP, the authenticator sends a "challenge" message to its peer.
2650 The peer uses a one-way hash function to encrypt the
2651 challenge and sends the result back.
2652 The authenticator does the same, and compares the results.
2653 The advantage of this mechanism is that no
2654 passwords are sent across the connection.
2655 A challenge is made when the connection is first made.
2656 Subsequent challenges may occur.
2657 If you want to have your peer authenticate itself, you must
2660 .Pa /etc/ppp/ppp.conf ,
2661 and have an entry in
2662 .Pa /etc/ppp/ppp.secret
2665 When using CHAP as the client, you need only specify
2670 .Pa /etc/ppp/ppp.conf .
2671 CHAP is accepted by default.
2674 implementations use "MS-CHAP" rather than MD5 when encrypting the
2676 MS-CHAP is a combination of MD4 and DES.
2679 was built on a machine with DES libraries available, it will respond
2680 to MS-CHAP authentication requests, but will never request them.
2682 Default: Enabled and Accepted.
2683 This option decides if deflate
2684 compression will be used by the Compression Control Protocol (CCP).
2685 This is the same algorithm as used by the
2688 Note: There is a problem negotiating
2694 implementation available under many operating systems.
2696 (version 2.3.1) incorrectly attempts to negotiate
2698 compression using type
2700 as the CCP configuration type rather than type
2706 is actually specified as
2707 .Dq PPP Magna-link Variable Resource Compression
2711 is capable of negotiating with
2718 .Ar accept Ns No ed .
2720 Default: Disabled and Denied.
2721 This is a variance of the
2723 option, allowing negotiation with the
2728 section above for details.
2729 It is disabled by default as it violates
2732 Default: Disabled and Denied.
2733 This option allows DNS negotiation.
2738 will request that the peer confirms the entries in
2739 .Pa /etc/resolv.conf .
2740 If the peer NAKs our request (suggesting new IP numbers),
2741 .Pa /etc/resolv.conf
2742 is updated and another request is sent to confirm the new entries.
2745 .Dq accept Ns No ed,
2747 will answer any DNS queries requested by the peer rather than rejecting
2749 The answer is taken from
2750 .Pa /etc/resolv.conf
2753 command is used as an override.
2755 Default: Enabled and Accepted.
2756 This option allows control over whether we
2757 negotiate an endpoint discriminator.
2758 We only send our discriminator if
2763 We reject the peers discriminator if
2767 Default: Disabled and Accepted.
2768 The use of this authentication protocol
2769 is discouraged as it partially violates the authentication protocol by
2770 implementing two different mechanisms (LANMan & NT) under the guise of
2771 a single CHAP type (0x80).
2773 uses a simple DES encryption mechanism and is the least secure of the
2774 CHAP alternatives (although is still more secure than PAP).
2778 description below for more details.
2780 Default: Disabled and Accepted.
2781 This option decides if Link Quality Requests will be sent or accepted.
2782 LQR is a protocol that allows
2784 to determine that the link is down without relying on the modems
2786 When LQR is enabled,
2792 below) as part of the LCP request.
2793 If the peer agrees, both sides will
2794 exchange LQR packets at the agreed frequency, allowing detailed link
2795 quality monitoring by enabling LQM logging.
2796 If the peer does not agree, and if the
2803 These packets pass no information of interest, but they
2805 be replied to by the peer.
2812 will abruptly drop the connection if 5 unacknowledged packets have been
2813 sent rather than sending a 6th.
2814 A message is logged at the
2816 level, and any appropriate
2818 values are honoured as if the peer were responsible for dropping the
2823 command description for differences in behaviour prior to
2827 Default: Enabled and Accepted.
2828 This is Microsoft Point to Point Encryption scheme.
2829 MPPE key size can be
2830 40-, 56- and 128-bits.
2835 Default: Disabled and Accepted.
2836 It is very similar to standard CHAP (type 0x05)
2837 except that it issues challenges of a fixed 16 bytes in length and uses a
2838 combination of MD4, SHA-1 and DES to encrypt the challenge rather than using the
2839 standard MD5 mechanism.
2841 Default: Disabled and Accepted.
2842 The use of this authentication protocol
2843 is discouraged as it partially violates the authentication protocol by
2844 implementing two different mechanisms (LANMan & NT) under the guise of
2845 a single CHAP type (0x80).
2846 It is very similar to standard CHAP (type 0x05)
2847 except that it issues challenges of a fixed 8 bytes in length and uses a
2848 combination of MD4 and DES to encrypt the challenge rather than using the
2849 standard MD5 mechanism.
2850 CHAP type 0x80 for LANMan is also supported - see
2858 use CHAP type 0x80, when acting as authenticator with both
2859 .Dq enable Ns No d ,
2861 will rechallenge the peer up to three times if it responds using the wrong
2862 one of the two protocols.
2863 This gives the peer a chance to attempt using both protocols.
2867 acts as the authenticatee with both protocols
2868 .Dq accept Ns No ed ,
2869 the protocols are used alternately in response to challenges.
2871 Note: If only LANMan is enabled,
2873 (version 2.3.5) misbehaves when acting as authenticatee.
2875 the NT and the LANMan answers, but also suggests that only the NT answer
2878 Default: Disabled and Accepted.
2879 PAP stands for Password Authentication Protocol.
2880 Only one of PAP and CHAP (above) may be negotiated.
2881 With PAP, the ID and Password are sent repeatedly to the peer until
2882 authentication is acknowledged or the connection is terminated.
2883 This is a rather poor security mechanism.
2884 It is only performed when the connection is first established.
2885 If you want to have your peer authenticate itself, you must
2888 .Pa /etc/ppp/ppp.conf ,
2889 and have an entry in
2890 .Pa /etc/ppp/ppp.secret
2891 for the peer (although see the
2897 When using PAP as the client, you need only specify
2902 .Pa /etc/ppp/ppp.conf .
2903 PAP is accepted by default.
2905 Default: Enabled and Accepted.
2906 This option decides if Predictor 1
2907 compression will be used by the Compression Control Protocol (CCP).
2909 Default: Enabled and Accepted.
2910 This option is used to negotiate
2911 PFC (Protocol Field Compression), a mechanism where the protocol
2912 field number is reduced to one octet rather than two.
2914 Default: Enabled and Accepted.
2915 This option determines if
2917 will request and accept requests for short
2919 sequence numbers when negotiating multi-link mode.
2920 This is only applicable if our MRRU is set (thus enabling multi-link).
2922 Default: Enabled and Accepted.
2923 This option determines if Van Jacobson header compression will be used.
2926 The following options are not actually negotiated with the peer.
2927 Therefore, accepting or denying them makes no sense.
2931 When this option is enabled,
2935 requests to the peer at the frequency defined by
2939 requests will supersede
2941 requests if enabled and negotiated.
2950 was considered enabled if lqr was enabled and negotiated, otherwise it was
2951 considered disabled.
2952 For the same behaviour, it is now necessary to
2956 .It filter-decapsulation
2958 When this option is enabled,
2960 will examine UDP frames to see if they actually contain a
2962 frame as their payload.
2963 If this is the case, all filters will operate on the payload rather
2964 than the actual packet.
2966 This is useful if you want to send PPPoUDP traffic over a
2968 link, but want that link to do smart things with the real data rather than
2971 The UDP frame payload must not be compressed in any way, otherwise
2973 will not be able to interpret it.
2974 It is therefore recommended that you
2975 .Ic disable vj pred1 deflate
2977 .Ic deny vj pred1 deflate
2978 in the configuration for the
2980 invocation with the udp link.
2983 Forces execution of the configured chat scripts in
2992 exchanges low-level LCP, CCP and IPCP configuration traffic, the
2994 field of any replies is expected to be the same as that of the request.
2997 drops any reply packets that do not contain the expected identifier
2998 field, reporting the fact at the respective log level.
3003 will ignore the identifier field.
3008 This option simply tells
3010 to add new interface addresses to the interface rather than replacing them.
3011 The option can only be enabled if network address translation is enabled
3012 .Pq Dq nat enable yes .
3014 With this option enabled,
3016 will pass traffic for old interface addresses through the NAT
3020 resulting in the ability (in
3022 mode) to properly connect the process that caused the PPP link to
3023 come up in the first place.
3033 to attempt to negotiate IP control protocol capabilities and if
3034 successful to exchange IP datagrams with the peer.
3039 to attempt to negotiate IPv6 control protocol capabilities and if
3040 successful to exchange IPv6 datagrams with the peer.
3045 runs as a Multi-link server, a different
3047 instance initially receives each connection.
3048 After determining that
3049 the link belongs to an already existing bundle (controlled by another
3053 will transfer the link to that process.
3055 If the link is a tty device or if this option is enabled,
3057 will not exit, but will change its process name to
3059 and wait for the controlling
3061 to finish with the link and deliver a signal back to the idle process.
3062 This prevents the confusion that results from
3064 parent considering the link resource available again.
3066 For tty devices that have entries in
3068 this is necessary to prevent another
3070 from being started, and for program links such as
3074 from exiting due to the death of its child.
3077 cannot determine its parents requirements (except for the tty case), this
3078 option must be enabled manually depending on the circumstances.
3085 will automatically loop back packets being sent
3086 out with a destination address equal to that of the
3091 will send the packet, probably resulting in an ICMP redirect from
3093 It is convenient to have this option enabled when
3094 the interface is also the default route as it avoids the necessity
3095 of a loopback route.
3098 This option controls whether
3102 attribute to the RADIUS server when RADIUS is in use
3103 .Pq see Dq set radius .
3105 Note, at least one of
3113 prior to version 3.4.1 did not send the
3115 attribute as it was reported to break the Radiator RADIUS server.
3116 As the latest rfc (2865) no longer hints that only one of
3120 should be sent (as rfc 2138 did),
3122 now sends both and leaves it up to the administrator that chooses to use
3123 bad RADIUS implementations to
3124 .Dq disable NAS-IP-Address .
3127 This option controls whether
3131 attribute to the RADIUS server when RADIUS is in use
3132 .Pq see Dq set radius .
3134 Note, at least one of
3141 Enabling this option will tell the PAP authentication
3142 code to use the password database (see
3144 to authenticate the caller if they cannot be found in the
3145 .Pa /etc/ppp/ppp.secret
3147 .Pa /etc/ppp/ppp.secret
3148 is always checked first.
3149 If you wish to use passwords from
3151 but also to specify an IP number or label for a given client, use
3153 as the client password in
3154 .Pa /etc/ppp/ppp.secret .
3157 Enabling this option will tell
3159 to proxy ARP for the peer.
3162 will make an entry in the ARP table using
3166 address of the local network in which
3169 This allows other machines connecteed to the LAN to talk to
3170 the peer as if the peer itself was connected to the LAN.
3171 The proxy entry cannot be made unless
3173 is an address from a LAN.
3176 Enabling this will tell
3178 to add proxy arp entries for every IP address in all class C or
3179 smaller subnets routed via the tun interface.
3181 Proxy arp entries are only made for sticky routes that are added
3185 No proxy arp entries are made for the interface address itself
3193 command is used with the
3199 values, entries are stored in the
3202 Each time these variables change, this list is re-applied to the routing table.
3204 Disabling this option will prevent the re-application of sticky routes,
3207 list will still be maintained.
3208 .It Oo tcp Oc Ns No mssfixup
3212 to adjust TCP SYN packets so that the maximum receive segment
3213 size is not greater than the amount allowed by the interface MTU.
3218 to gather throughput statistics.
3219 Input and output is sampled over
3220 a rolling 5 second window, and current, best and total figures are retained.
3221 This data is output when the relevant
3223 layer shuts down, and is also available using the
3226 Throughput statistics are available at the
3233 Normally, when a user is authenticated using PAP or CHAP, and when
3237 mode, an entry is made in the utmp and wtmp files for that user.
3238 Disabling this option will tell
3240 not to make any utmp or wtmp entries.
3241 This is usually only necessary if
3242 you require the user to both login and authenticate themselves.
3247 .Ar dest Ns Op / Ns Ar nn
3252 is the destination IP address.
3253 The netmask is specified either as a number of bits with
3255 or as an IP number using
3260 with no mask refers to the default route.
3261 It is also possible to use the literal name
3266 is the next hop gateway to get to the given
3271 command for further details.
3273 It is possible to use the symbolic names
3279 as the destination, and
3286 is replaced with the interface IP address,
3288 is replaced with the interface IP destination (peer) address,
3290 is replaced with the interface IPv6 address, and
3292 is replaced with the interface IPv6 destination address,
3299 then if the route already exists, it will be updated as with the
3303 for further details).
3305 Routes that contain the
3313 constants are considered
3315 They are stored in a list (use
3317 to see the list), and each time the value of one of these variables
3318 changes, the appropriate routing table entries are updated.
3319 This facility may be disabled using
3320 .Dq disable sroutes .
3321 .It allow Ar command Op Ar args
3322 This command controls access to
3324 and its configuration files.
3325 It is possible to allow user-level access,
3326 depending on the configuration file label and on the mode that
3329 For example, you may wish to configure
3339 User id 0 is immune to these commands.
3341 .It allow user Ns Xo
3343 .Ar logname Ns No ...
3345 By default, only user id 0 is allowed access to
3347 If this command is used, all of the listed users are allowed access to
3348 the section in which the
3353 section is always checked first (even though it is only ever automatically
3356 commands are cumulative in a given section, but users allowed in any given
3357 section override users allowed in the default section, so it is possible to
3358 allow users access to everything except a given label by specifying default
3361 section, and then specifying a new user list for that label.
3365 is specified, access is allowed to all users.
3366 .It allow mode Ns Xo
3370 By default, access using any
3373 If this command is used, it restricts the access
3375 allowed to load the label under which this command is specified.
3380 command overrides any previous settings, and the
3382 section is always checked first.
3394 When running in multi-link mode, a section can be loaded if it allows
3396 of the currently existing line modes.
3399 .It nat Ar command Op Ar args
3400 This command allows the control of the network address translation (also
3401 known as masquerading or IP aliasing) facilities that are built into
3403 NAT is done on the external interface only, and is unlikely to make sense
3408 If nat is enabled on your system (it may be omitted at compile time),
3409 the following commands are possible:
3411 .It nat enable yes|no
3412 This command either switches network address translation on or turns it off.
3415 command line flag is synonymous with
3416 .Dq nat enable yes .
3417 .It nat addr Op Ar addr_local addr_alias
3418 This command allows data for
3422 It is useful if you own a small number of real IP numbers that
3423 you wish to map to specific machines behind your gateway.
3424 .It nat deny_incoming yes|no
3425 If set to yes, this command will refuse all incoming packets where an
3426 aliasing link does not already exist.
3428 .Sx CONCEPTUAL BACKGROUND
3431 for a description of what an
3435 It should be noted under what circumstances an aliasing link is
3438 It may be necessary to further protect your network from outside
3439 connections using the
3445 This command gives a summary of available nat commands.
3447 This option causes various NAT statistics and information to
3448 be logged to the file
3449 .Pa /var/log/alias.log .
3450 .It nat port Ar proto Ar targetIP Ns Xo
3451 .No : Ns Ar targetPort Ns
3453 .No - Ns Ar targetPort
3456 .No - Ns Ar aliasPort
3457 .Oc Oo Ar remoteIP : Ns
3460 .No - Ns Ar remotePort
3464 This command causes incoming
3478 A range of port numbers may be specified as shown above.
3479 The ranges must be of the same size.
3483 is specified, only data coming from that IP number is redirected.
3487 (indicating any source port)
3488 or a range of ports the same size as the other ranges.
3490 This option is useful if you wish to run things like Internet phone on
3491 machines behind your gateway, but is limited in that connections to only
3492 one interior machine per source machine and target port are possible.
3493 .It nat proto Ar proto localIP Oo
3494 .Ar publicIP Op Ar remoteIP
3498 to redirect packets of protocol type
3502 to the internal address
3507 is specified, only packets destined for that address are matched,
3508 otherwise the default alias address is used.
3512 is specified, only packets matching that source address are matched,
3514 This command is useful for redirecting tunnel endpoints to an internal machine,
3517 .Dl nat proto ipencap 10.0.0.1
3518 .It "nat proxy cmd" Ar arg Ns No ...
3521 to proxy certain connections, redirecting them to a given server.
3522 Refer to the description of
3523 .Fn PacketAliasProxyRule
3526 for details of the available commands.
3527 .It nat punch_fw Op Ar base count
3530 to punch holes in the firewall for FTP or IRC DCC connections.
3531 This is done dynamically by installing termporary firewall rules which
3532 allow a particular connection (and only that connection) to go through
3534 The rules are removed once the corresponding connection terminates.
3538 rules starting from rule number
3540 will be used for punching firewall holes.
3541 The range will be cleared when the
3545 If no arguments are given, firewall punching is disabled.
3546 .It nat skinny_port Op Ar port
3549 which TCP port is used by the Skinny Station protocol.
3551 Cisco IP phones to communicate with Cisco Call Managers to setup voice
3553 The typical port used by Skinny is 2000.
3555 If no argument is given, skinny aliasing is disabled.
3556 .It nat same_ports yes|no
3557 When enabled, this command will tell the network address translation engine to
3558 attempt to avoid changing the port number on outgoing packets.
3560 if you want to support protocols such as RPC and LPD which require
3561 connections to come from a well known port.
3562 .It nat target Op Ar address
3563 Set the given target address or clear it if no address is given.
3564 The target address is used by libalias to specify how to NAT incoming packets
3566 If a target address is not set or if
3568 is given, packets are not altered and are allowed to route to the internal
3571 The target address may be set to
3573 in which case libalias will redirect all packets to the interface address.
3574 .It nat use_sockets yes|no
3575 When enabled, this option tells the network address translation engine to
3576 create a socket so that it can guarantee a correct incoming ftp data or
3578 .It nat unregistered_only yes|no
3579 Only alter outgoing packets with an unregistered source address.
3580 According to RFC 1918, unregistered source addresses
3581 are 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16.
3584 These commands are also discussed in the file
3586 which comes with the source distribution.
3593 is executed in the background with the following words replaced:
3594 .Bl -tag -width COMPILATIONDATE
3596 This is replaced with the local
3602 .It Li COMPILATIONDATE
3603 In previous software revisions, this was replaced with the date on which
3606 This is no longer supported as it breaks the ability to recompile the same
3607 code to produce an exact duplicate of a previous compilation.
3609 These are replaced with the primary and secondary nameserver IP numbers.
3610 If nameservers are negotiated by IPCP, the values of these macros will change.
3612 This is replaced with the local endpoint discriminator value.
3617 This is replaced with the peers IP number.
3619 This is replaced with the peers IPv6 number.
3621 This is replaced with the name of the interface that is in use.
3623 This is replaced with the number of IP bytes received since the connection
3626 This is replaced with the number of IP bytes sent since the connection
3629 This is replaced with the number of IP packets received since the connection
3632 This is replaced with the number of IP packets sent since the connection
3635 This is replaced with the number of IPv6 bytes received since the connection
3637 .It Li IPV6OCTETSOUT
3638 This is replaced with the number of IPv6 bytes sent since the connection
3640 .It Li IPV6PACKETSIN
3641 This is replaced with the number of IPv6 packets received since the connection
3643 .It Li IPV6PACKETSOUT
3644 This is replaced with the number of IPv6 packets sent since the connection
3647 This is replaced with the last label name used.
3648 A label may be specified on the
3650 command line, via the
3658 This is replaced with the IP number assigned to the local interface.
3660 This is replaced with the IPv6 number assigned to the local interface.
3662 This is replaced with the number of bytes received since the connection
3665 This is replaced with the number of bytes sent since the connection
3668 This is replaced with the number of packets received since the connection
3671 This is replaced with the number of packets sent since the connection
3674 This is replaced with the value of the peers endpoint discriminator.
3676 This is replaced with the current process id.
3678 This is replaced with the name of the diagnostic socket.
3680 This is replaced with the bundle uptime in HH:MM:SS format.
3682 This is replaced with the username that has been authenticated with PAP or
3684 Normally, this variable is assigned only in -direct mode.
3685 This value is available irrespective of whether utmp logging is enabled.
3687 This is replaced with the current version number of
3691 These substitutions are also done by the
3698 If you wish to pause
3700 while the command executes, use the
3703 .It clear physical|ipcp|ipv6 Op current|overall|peak...
3704 Clear the specified throughput values at either the
3712 is specified, context must be given (see the
3715 If no second argument is given, all values are cleared.
3716 .It clone Ar name Ns Xo
3717 .Op \&, Ns Ar name Ns
3720 Clone the specified link, creating one or more new links according to the
3723 This command must be used from the
3725 command below unless you have only got a single link (in which case that
3726 link becomes the default).
3727 Links may be removed using the
3731 The default link name is
3733 .It close Op lcp|ccp Ns Op !\&
3734 If no arguments are given, the relevant protocol layers will be brought
3735 down and the link will be closed.
3738 is specified, the LCP layer is brought down, but
3740 will not bring the link offline.
3741 It is subsequently possible to use
3744 to talk to the peer machine if, for example, something like
3749 is specified, only the relevant compression layer is closed.
3752 is used, the compression layer will remain in the closed state, otherwise
3753 it will re-enter the STOPPED state, waiting for the peer to initiate
3754 further CCP negotiation.
3755 In any event, this command does not disconnect the user from
3766 This command deletes the route with the given
3773 all non-direct entries in the routing table for the current interface,
3776 entries are deleted.
3781 the default route is deleted.
3789 will not complain if the route does not already exist.
3790 .It dial|call Oo Ar label Oc Ns Xo
3793 This command is the equivalent of
3797 and is provided for backwards compatibility.
3798 .It down Op Ar lcp|ccp
3799 Bring the relevant layer down ungracefully, as if the underlying layer
3800 had become unavailable.
3801 It is not considered polite to use this command on
3802 a Finite State Machine that is in the OPEN state.
3804 supplied, the entire link is closed (or if no context is given, all links
3810 layer is terminated but the device is not brought offline and the link
3814 is specified, only the relevant compression layer(s) are terminated.
3815 .It help|? Op Ar command
3816 Show a list of available commands.
3819 is specified, show the usage string for that command.
3820 .It ident Op Ar text Ns No ...
3821 Identify the link to the peer using
3825 is empty, link identification is disabled.
3826 It is possible to use any of the words described for the
3831 command for details of when
3833 identifies itself to the peer.
3834 .It iface Ar command Op args
3835 This command is used to control the interface used by
3838 may be one of the following:
3842 .Ar addr Ns Op / Ns Ar bits
3853 combination to the interface.
3854 Instead of specifying
3858 (with no space between it and
3860 If the given address already exists, the command fails unless the
3862 is used - in which case the previous interface address entry is overwritten
3863 with the new one, allowing a change of netmask or peer address.
3874 .Dq 255.255.255.255 .
3875 This address (the broadcast address) is the only duplicate peer address that
3878 .It iface clear Op INET | INET6
3879 If this command is used while
3881 is in the OPENED state or while in
3883 mode, all addresses except for the NCP negotiated address are deleted
3887 is not in the OPENED state and is not in
3889 mode, all interface addresses are deleted.
3891 If the INET or INET6 arguments are used, only addresses for that address
3894 .It iface delete Ns Xo
3899 This command deletes the given
3904 is used, no error is given if the address is not currently assigned to
3905 the interface (and no deletion takes place).
3906 .It iface name Ar name
3907 Renames the interface to
3909 .It iface description Ar description
3910 Sets the interface description to
3912 Useful if you have many interfaces on your system.
3914 Shows the current state and current addresses for the interface.
3915 It is much the same as running
3916 .Dq ifconfig INTERFACE .
3917 .It iface help Op Ar sub-command
3918 This command, when invoked without
3920 will show a list of possible
3922 sub-commands and a brief synopsis for each.
3925 only the synopsis for the given sub-command is shown.
3927 .It Oo data Oc Ns Xo
3929 .Ar name Ns Oo , Ns Ar name Oc Ns ... Ar command Op Ar args
3931 This command may prefix any other command if the user wishes to
3932 specify which link the command should affect.
3933 This is only applicable after multiple links have been created in Multi-link
3939 specifies the name of an existing link.
3942 is a comma separated list,
3944 is executed on each link.
3950 is executed on all links.
3951 .It load Oo Ar label Oc Ns Xo
3974 will not attempt to make an immediate connection.
3975 .It log Ar word Ns No ...
3976 Send the given word(s) to the log file with the prefix
3978 Word substitutions are done as explained under the
3981 .It open Op lcp|ccp|ipcp
3982 This is the opposite of the
3985 All closed links are immediately brought up apart from second and subsequent
3987 links - these will come up based on the
3989 command that has been used.
3993 argument is used while the LCP layer is already open, LCP will be
3995 This allows various LCP options to be changed, after which
3997 can be used to put them into effect.
3998 After renegotiating LCP,
3999 any agreed authentication will also take place.
4003 argument is used, the relevant compression layer is opened.
4004 Again, if it is already open, it will be renegotiated.
4008 argument is used, the link will be brought up as normal, but if
4009 IPCP is already open, it will be renegotiated and the network
4010 interface will be reconfigured.
4012 It is probably not good practice to re-open the PPP state machines
4013 like this as it is possible that the peer will not behave correctly.
4016 however useful as a way of forcing the CCP or VJ dictionaries to be reset.
4018 Specify the password required for access to the full
4021 This password is required when connecting to the diagnostic port (see the
4032 logging is active, instead, the literal string
4038 is executed from the controlling connection or from a command file,
4039 ppp will exit after closing all connections.
4040 Otherwise, if the user
4041 is connected to a diagnostic socket, the connection is simply dropped.
4047 will exit despite the source of the command after closing all existing
4050 This command removes the given link.
4051 It is only really useful in multi-link mode.
4052 A link must be in the
4054 state before it is removed.
4055 .It rename|mv Ar name
4056 This command renames the given link to
4060 is already used by another link.
4062 The default link name is
4069 may make the log file more readable.
4070 .It resolv Ar command
4071 This command controls
4078 starts up, it loads the contents of this file into memory and retains this
4079 image for future use.
4081 is one of the following:
4082 .Bl -tag -width readonly
4085 .Pa /etc/resolv.conf
4091 will still attempt to negotiate nameservers with the peer, making the results
4097 This is the opposite of the
4102 .Pa /etc/resolv.conf
4104 This may be necessary if for example a DHCP client overwrote
4105 .Pa /etc/resolv.conf .
4108 .Pa /etc/resolv.conf
4109 with the version originally read at startup or with the last
4112 This is sometimes a useful command to put in the
4113 .Pa /etc/ppp/ppp.linkdown
4117 .Pa /etc/resolv.conf
4119 This command will work even if the
4121 command has been used.
4122 It may be useful as a command in the
4123 .Pa /etc/ppp/ppp.linkup
4124 file if you wish to defer updating
4125 .Pa /etc/resolv.conf
4126 until after other commands have finished.
4131 .Pa /etc/resolv.conf
4136 successfully negotiates a DNS.
4137 This is the opposite of the
4142 This option is not (yet) implemented.
4146 to identify itself to the peer.
4147 The link must be in LCP state or higher.
4148 If no identity has been set (via the
4154 When an identity has been set,
4156 will automatically identify itself when it sends or receives a configure
4157 reject, when negotiation fails or when LCP reaches the opened state.
4159 Received identification packets are logged to the LCP log (see
4161 for details) and are never responded to.
4166 This option allows the setting of any of the following variables:
4168 .It set accmap Ar hex-value
4169 ACCMap stands for Asynchronous Control Character Map.
4171 negotiated with the peer, and defaults to a value of 00000000 in hex.
4172 This protocol is required to defeat hardware that depends on passing
4173 certain characters from end to end (such as XON/XOFF etc).
4175 For the XON/XOFF scenario, use
4176 .Dq set accmap 000a0000 .
4177 .It set Oo auth Oc Ns Xo
4180 This sets the authentication key (or password) used in client mode
4181 PAP or CHAP negotiation to the given value.
4182 It also specifies the
4183 password to be used in the dial or login scripts in place of the
4185 sequence, preventing the actual password from being logged.
4190 logging is in effect,
4194 for security reasons.
4196 If the first character of
4198 is an exclamation mark
4201 treats the remainder of the string as a program that must be executed
4213 it is treated as a single literal
4215 otherwise, ignoring the
4218 is parsed as a program to execute in the same was as the
4220 command above, substituting special names in the same manner.
4223 will feed the program three lines of input, each terminated by a newline
4227 The host name as sent in the CHAP challenge.
4229 The challenge string as sent in the CHAP challenge.
4235 Two lines of output are expected:
4240 to be sent with the CHAP response.
4244 which is encrypted with the challenge and request id, the answer being sent
4245 in the CHAP response packet.
4250 in this manner, it is expected that the host challenge is a series of ASCII
4251 digits or characters.
4252 An encryption device or Secure ID card is usually
4253 required to calculate the secret appropriate for the given challenge.
4254 .It set authname Ar id
4255 This sets the authentication id used in client mode PAP or CHAP negotiation.
4259 mode with CHAP enabled,
4261 is used in the initial authentication challenge and should normally be set to
4262 the local machine name.
4264 .Ar min-percent max-percent period
4266 These settings apply only in multi-link mode and default to zero, zero and
4272 mode link is available, only the first link is made active when
4274 first reads data from the tun device.
4277 link will be opened only when the current bundle throughput is at least
4279 percent of the total bundle bandwidth for
4282 When the current bundle throughput decreases to
4284 percent or less of the total bundle bandwidth for
4288 link will be brought down as long as it is not the last active link.
4290 Bundle throughput is measured as the maximum of inbound and outbound
4293 The default values cause
4295 links to simply come up one at a time.
4297 Certain devices cannot determine their physical bandwidth, so it
4298 is sometimes necessary to use the
4300 command (described below) to make
4303 .It set bandwidth Ar value
4304 This command sets the connection bandwidth in bits per second.
4306 must be greater than zero.
4307 It is currently only used by the
4310 .It set callback Ar option Ns No ...
4311 If no arguments are given, callback is disabled, otherwise,
4315 mode, will accept) one of the given
4316 .Ar option Ns No s .
4317 In client mode, if an
4321 will request a different
4323 until no options remain at which point
4325 will terminate negotiations (unless
4327 is one of the specified
4331 will accept any of the given protocols - but the client
4333 request one of them.
4334 If you wish callback to be optional, you must {include}
4340 are as follows (in this order of preference):
4343 The callee is expected to decide the callback number based on
4347 is the callee, the number should be specified as the fifth field of
4349 .Pa /etc/ppp/ppp.secret .
4351 Microsoft's callback control protocol is used.
4356 If you wish to negotiate
4358 in client mode but also wish to allow the server to request no callback at
4359 CBCP negotiation time, you must specify both
4363 as callback options.
4365 .Ar number Ns Op , Ns Ar number Ns
4368 The caller specifies the
4374 should be either a comma separated list of allowable numbers or a
4376 meaning any number is permitted.
4379 is the caller, only a single number should be specified.
4381 Note, this option is very unsafe when used with a
4383 as a malicious caller can tell
4385 to call any (possibly international) number without first authenticating
4388 If the peer does not wish to do callback at all,
4390 will accept the fact and continue without callback rather than terminating
4392 This is required (in addition to one or more other callback
4393 options) if you wish callback to be optional.
4397 .No *| Ns Ar number Ns Oo
4398 .No , Ns Ar number Ns ...\& Oc
4399 .Op Ar delay Op Ar retry
4401 If no arguments are given, CBCP (Microsoft's CallBack Control Protocol)
4402 is disabled - ie, configuring CBCP in the
4404 command will result in
4406 requesting no callback in the CBCP phase.
4409 attempts to use the given phone
4410 .Ar number Ns No (s).
4415 will insist that the client uses one of these numbers, unless
4417 is used in which case the client is expected to specify the number.
4421 will attempt to use one of the given numbers (whichever it finds to
4422 be agreeable with the peer), or if
4426 will expect the peer to specify the number.
4428 .No off| Ns Ar seconds Ns Op !\&
4432 checks for the existence of carrier depending on the type of device
4433 that has been opened:
4434 .Bl -tag -width XXX -offset XXX
4435 .It Terminal Devices
4436 Carrier is checked one second after the login script is complete.
4439 assumes that this is because the device does not support carrier (which
4442 NULL-modem cables), logs the fact and stops checking
4445 As ptys do not support the TIOCMGET ioctl, the tty device will switch all
4446 carrier detection off when it detects that the device is a pty.
4447 .It PPPoE (netgraph) Devices
4448 Carrier is checked once per second for 5 seconds.
4449 If it is not set after
4450 the fifth second, the connection attempt is considered to have failed and
4451 the device is closed.
4452 Carrier is always required for PPPoE devices.
4455 All other device types do not support carrier.
4456 Setting a carrier value will
4457 result in a warning when the device is opened.
4459 Some modems take more than one second after connecting to assert the carrier
4461 If this delay is not increased, this will result in
4463 inability to detect when the link is dropped, as
4465 assumes that the device is not asserting carrier.
4469 command overrides the default carrier behaviour.
4471 specifies the maximum number of seconds that
4473 should wait after the dial script has finished before deciding if
4474 carrier is available or not.
4480 will not check for carrier on the device, otherwise
4482 will not proceed to the login script until either carrier is detected
4485 has elapsed, at which point
4487 assumes that the device will not set carrier.
4489 If no arguments are given, carrier settings will go back to their default
4494 is followed immediately by an exclamation mark
4500 If carrier is not detected after
4502 seconds, the link will be disconnected.
4503 .It set choked Op Ar timeout
4504 This sets the number of seconds that
4506 will keep a choked output queue before dropping all pending output packets.
4509 is less than or equal to zero or if
4511 is not specified, it is set to the default value of
4514 A choked output queue occurs when
4516 has read a certain number of packets from the local network for transmission,
4517 but cannot send the data due to link failure (the peer is busy etc.).
4519 will not read packets indefinitely.
4520 Instead, it reads up to
4526 packets in multi-link mode), then stops reading the network interface
4529 seconds have passed or at least one packet has been sent.
4533 seconds pass, all pending output packets are dropped.
4534 .It set ctsrts|crtscts on|off
4535 This sets hardware flow control.
4536 Hardware flow control is
4539 .It set deflate Ar out-winsize Op Ar in-winsize
4540 This sets the DEFLATE algorithms default outgoing and incoming window
4546 must be values between
4554 will insist that this window size is used and will not accept any other
4555 values from the peer.
4556 .It set dns Op Ar primary Op Ar secondary
4557 This command specifies DNS overrides for the
4562 command description above for details.
4563 This command does not affect the IP numbers requested using
4565 .It set device|line Xo
4568 This sets the device(s) to which
4570 will talk to the given
4573 All serial device names are expected to begin with
4575 Serial devices are usually called
4582 it must either begin with an exclamation mark
4585 .No PPPoE: Ns Ar iface Ns Xo
4586 .Op \&: Ns Ar provider Ns
4590 enabled systems), or be of the format
4592 .Ar host : port Op /tcp|udp .
4595 If it begins with an exclamation mark, the rest of the device name is
4596 treated as a program name, and that program is executed when the device
4598 Standard input, output and error are fed back to
4600 and are read and written as if they were a regular device.
4603 .No PPPoE: Ns Ar iface Ns Xo
4604 .Op \&: Ns Ar provider Ns
4606 specification is given,
4608 will attempt to create a
4610 over Ethernet connection using the given
4618 will attempt to load it using
4620 If this fails, an external program must be used such as the
4622 program available under
4626 is passed as the service name in the PPPoE Discovery Initiation (PADI)
4628 If no provider is given, an empty value will be used.
4630 When a PPPoE connection is established,
4632 will place the name of the Access Concentrator in the environment variable
4639 for further details.
4642 .Ar host Ns No : Ns Ar port Ns Oo
4645 specification is given,
4647 will attempt to connect to the given
4655 suffix is not provided, the default is
4657 Refer to the section on
4658 .Em PPP OVER TCP and UDP
4659 above for further details.
4665 will attempt to open each one in turn until it succeeds or runs out of
4667 .It set dial Ar chat-script
4668 This specifies the chat script that will be used to dial the other
4675 and to the example configuration files for details of the chat script
4677 It is possible to specify some special
4679 in your chat script as follows:
4682 When used as the last character in a
4684 string, this indicates that a newline should not be appended.
4686 When the chat script encounters this sequence, it delays two seconds.
4688 When the chat script encounters this sequence, it delays for one quarter of
4691 This is replaced with a newline character.
4693 This is replaced with a carriage return character.
4695 This is replaced with a space character.
4697 This is replaced with a tab character.
4699 This is replaced by the current phone number (see
4703 This is replaced by the current
4709 This is replaced by the current
4716 Note that two parsers will examine these escape sequences, so in order to
4719 see the escape character, it is necessary to escape it from the
4720 .Sq command parser .
4721 This means that in practice you should use two escapes, for example:
4722 .Bd -literal -offset indent
4723 set dial "... ATDT\\\\T CONNECT"
4726 It is also possible to execute external commands from the chat script.
4727 To do this, the first character of the expect or send string is an
4730 If a literal exclamation mark is required, double it up to
4732 and it will be treated as a single literal
4734 When the command is executed, standard input and standard output are
4735 directed to the open device (see the
4737 command), and standard error is read by
4739 and substituted as the expect or send string.
4742 is running in interactive mode, file descriptor 3 is attached to
4745 For example (wrapped for readability):
4746 .Bd -literal -offset indent
4747 set login "TIMEOUT 5 \\"\\" \\"\\" login:--login: ppp \e
4748 word: ppp \\"!sh \\\\-c \\\\\\"echo \\\\-n label: >&2\\\\\\"\\" \e
4749 \\"!/bin/echo in\\" HELLO"
4752 would result in the following chat sequence (output using the
4753 .Sq set log local chat
4754 command before dialing):
4755 .Bd -literal -offset indent
4760 Chat: Expecting: login:--login:
4761 Chat: Wait for (5): login:
4763 Chat: Expecting: word:
4764 Chat: Wait for (5): word:
4766 Chat: Expecting: !sh \\-c "echo \\-n label: >&2"
4767 Chat: Exec: sh -c "echo -n label: >&2"
4768 Chat: Wait for (5): !sh \\-c "echo \\-n label: >&2" --> label:
4769 Chat: Exec: /bin/echo in
4771 Chat: Expecting: HELLO
4772 Chat: Wait for (5): HELLO
4776 Note (again) the use of the escape character, allowing many levels of
4778 Here, there are four parsers at work.
4779 The first parses the original line, reading it as three arguments.
4780 The second parses the third argument, reading it as 11 arguments.
4781 At this point, it is
4784 signs are escaped, otherwise this parser will see them as constituting
4785 an expect-send-expect sequence.
4788 character is seen, the execution parser reads the first command as three
4791 itself expands the argument after the
4793 As we wish to send the output back to the modem, in the first example
4794 we redirect our output to file descriptor 2 (stderr) so that
4796 itself sends and logs it, and in the second example, we just output to stdout,
4797 which is attached directly to the modem.
4799 This, of course means that it is possible to execute an entirely external
4801 command rather than using the internal one.
4804 for a good alternative.
4806 The external command that is executed is subjected to the same special
4807 word expansions as the
4810 .It set enddisc Op label|IP|MAC|magic|psn value
4811 This command sets our local endpoint discriminator.
4812 If set prior to LCP negotiation, and if no
4814 command has been used,
4816 will send the information to the peer using the LCP endpoint discriminator
4818 The following discriminators may be set:
4819 .Bl -tag -width indent
4821 The current label is used.
4823 Our local IP number is used.
4824 As LCP is negotiated prior to IPCP, it is
4825 possible that the IPCP layer will subsequently change this value.
4827 it does, the endpoint discriminator stays at the old value unless manually
4830 This is similar to the
4832 option above, except that the MAC address associated with the local IP
4834 If the local IP number is not resident on any Ethernet
4835 interface, the command will fail.
4837 As the local IP number defaults to whatever the machine host name is,
4839 is usually done prior to any
4843 A 20 digit random number is used.
4844 Care should be taken when using magic numbers as restarting
4846 or creating a link using a different
4848 invocation will also use a different magic number and will therefore not
4849 be recognised by the peer as belonging to the same bundle.
4850 This makes it unsuitable for
4858 should be set to an absolute public switched network number with the
4862 If no arguments are given, the endpoint discriminator is reset.
4863 .It set escape Ar value...
4864 This option is similar to the
4867 It allows the user to specify a set of characters that will be
4869 as they travel across the link.
4870 .It set filter dial|alive|in|out Ar rule-no Xo
4871 .No permit|deny|clear| Ns Ar rule-no
4874 .Ar src_addr Ns Op / Ns Ar width
4875 .Op Ar dst_addr Ns Op / Ns Ar width
4877 .Op src lt|eq|gt Ar port
4878 .Op dst lt|eq|gt Ar port
4882 .Op timeout Ar secs ]
4885 supports four filter sets.
4888 filter specifies packets that keep the connection alive - resetting the
4892 filter specifies packets that cause
4899 filter specifies packets that are allowed to travel
4900 into the machine and the
4902 filter specifies packets that are allowed out of the machine.
4904 Filtering is done prior to any IP alterations that might be done by the
4905 NAT engine on outgoing packets and after any IP alterations that might
4906 be done by the NAT engine on incoming packets.
4907 By default all empty filter sets allow all packets to pass.
4908 Rules are processed in order according to
4910 (unless skipped by specifying a rule number as the
4912 Up to 40 rules may be given for each set.
4913 If a packet does not match
4914 any of the rules in a given set, it is discarded.
4919 filters, this means that the packet is dropped.
4922 filters it means that the packet will not reset the idle timer (even if
4924 .Ar in Ns No / Ns Ar out
4927 value) and in the case of
4929 filters it means that the packet will not trigger a dial.
4930 A packet failing to trigger a dial will be dropped rather than queued.
4933 .Sx PACKET FILTERING
4934 above for further details.
4935 .It set hangup Ar chat-script
4936 This specifies the chat script that will be used to reset the device
4937 before it is closed.
4938 It should not normally be necessary, but can
4939 be used for devices that fail to reset themselves properly on close.
4940 .It set help|? Op Ar command
4941 This command gives a summary of available set commands, or if
4943 is specified, the command usage is shown.
4944 .It set ifaddr Oo Ar myaddr Ns
4946 .Oo Ar hisaddr Ns Op / Ns Ar \&nn
4951 This command specifies the IP addresses that will be used during
4953 Addresses are specified using the format
4959 is the preferred IP, but
4961 specifies how many bits of the address we will insist on.
4964 is omitted, it defaults to
4966 unless the IP address is 0.0.0.0 in which case it defaults to
4969 If you wish to assign a dynamic IP number to the peer,
4971 may also be specified as a range of IP numbers in the format
4972 .Bd -ragged -offset indent
4973 .Ar \&IP Ns Oo \&- Ns Ar \&IP Ns Oc Ns Oo , Ns Ar \&IP Ns
4974 .Oo \&- Ns Ar \&IP Ns Oc Oc Ns ...
4979 .Dl set ifaddr 10.0.0.1 10.0.1.2-10.0.1.10,10.0.1.20
4983 as the local IP number, but may assign any of the given 10 IP
4984 numbers to the peer.
4985 If the peer requests one of these numbers,
4986 and that number is not already in use,
4988 will grant the peers request.
4989 This is useful if the peer wants
4990 to re-establish a link using the same IP number as was previously
4991 allocated (thus maintaining any existing tcp or udp connections).
4993 If the peer requests an IP number that is either outside
4994 of this range or is already in use,
4996 will suggest a random unused IP number from the range.
5000 is specified, it is used in place of
5002 in the initial IPCP negotiation.
5003 However, only an address in the
5005 range will be accepted.
5006 This is useful when negotiating with some
5008 implementations that will not assign an IP number unless their peer
5012 It should be noted that in
5016 will configure the interface immediately upon reading the
5018 line in the config file.
5019 In any other mode, these values are just
5020 used for IPCP negotiations, and the interface is not configured
5021 until the IPCP layer is up.
5025 argument may be overridden by the third field in the
5027 file once the client has authenticated itself
5031 .Sx AUTHENTICATING INCOMING CONNECTIONS
5032 section for details.
5034 In all cases, if the interface is already configured,
5036 will try to maintain the interface IP numbers so that any existing
5037 bound sockets will remain valid.
5038 .It set ifqueue Ar packets
5039 Set the maximum number of packets that
5041 will read from the tunnel interface while data cannot be sent to any of
5042 the available links.
5043 This queue limit is necessary to flow control outgoing data as the tunnel
5044 interface is likely to be far faster than the combined links available to
5049 is set to a value less than the number of links,
5051 will read up to that value regardless.
5052 This prevents any possible latency problems.
5054 The default value for
5058 .It set ccpretry|ccpretries Oo Ar timeout
5059 .Op Ar reqtries Op Ar trmtries
5061 .It set chapretry|chapretries Oo Ar timeout
5064 .It set ipcpretry|ipcpretries Oo Ar timeout
5065 .Op Ar reqtries Op Ar trmtries
5067 .It set ipv6cpretry|ipv6cpretries Oo Ar timeout
5068 .Op Ar reqtries Op Ar trmtries
5070 .It set lcpretry|lcpretries Oo Ar timeout
5071 .Op Ar reqtries Op Ar trmtries
5073 .It set papretry|papretries Oo Ar timeout
5076 These commands set the number of seconds that
5078 will wait before resending Finite State Machine (FSM) Request packets.
5081 for all FSMs is 3 seconds (which should suffice in most cases).
5085 is specified, it tells
5087 how many configuration request attempts it should make while receiving
5088 no reply from the peer before giving up.
5089 The default is 5 attempts for
5090 CCP, LCP and IPCP and 3 attempts for PAP and CHAP.
5094 is specified, it tells
5096 how many terminate requests should be sent before giving up waiting for the
5098 The default is 3 attempts.
5099 Authentication protocols are
5100 not terminated and it is therefore invalid to specify
5104 In order to avoid negotiations with the peer that will never converge,
5106 will only send at most 3 times the configured number of
5108 in any given negotiation session before giving up and closing that layer.
5114 This command allows the adjustment of the current log level.
5115 Refer to the Logging Facility section for further details.
5116 .It set login Ar chat-script
5119 compliments the dial-script.
5120 If both are specified, the login
5121 script will be executed after the dial script.
5122 Escape sequences available in the dial script are also available here.
5123 .It set logout Ar chat-script
5124 This specifies the chat script that will be used to logout
5125 before the hangup script is called.
5126 It should not normally be necessary.
5127 .It set lqrperiod|echoperiod Ar frequency
5128 This command sets the
5135 The default is 30 seconds.
5136 You must also use the
5140 commands if you wish to send
5144 requests to the peer.
5145 .It set mode Ar interactive|auto|ddial|background
5146 This command allows you to change the
5148 of the specified link.
5149 This is normally only useful in multi-link mode,
5150 but may also be used in uni-link mode.
5152 It is not possible to change a link that is
5157 Note: If you issue the command
5159 and have network address translation enabled, it may be useful to
5160 .Dq enable iface-alias
5164 to do the necessary address translations to enable the process that
5165 triggers the connection to connect once the link is up despite the
5166 peer assigning us a new (dynamic) IP address.
5167 .It set mppe Op 40|56|128|* Op stateless|stateful|*
5168 This option selects the encryption parameters used when negotiation
5170 MPPE can be disabled entirely with the
5173 If no arguments are given,
5175 will attempt to negotiate a stateful link with a 128 bit key, but
5176 will agree to whatever the peer requests (including no encryption
5179 If any arguments are given,
5183 on using MPPE and will close the link if it is rejected by the peer (Note;
5184 this behaviour can be overridden by a configured RADIUS server).
5186 The first argument specifies the number of bits that
5188 should insist on during negotiations and the second specifies whether
5190 should insist on stateful or stateless mode.
5191 In stateless mode, the
5192 encryption dictionary is re-initialised with every packet according to
5193 an encryption key that is changed with every packet.
5195 the encryption dictionary is re-initialised every 256 packets or after
5196 the loss of any data and the key is changed every 256 packets.
5197 Stateless mode is less efficient but is better for unreliable transport
5199 .It set mrru Op Ar value
5200 Setting this option enables Multi-link PPP negotiations, also known as
5201 Multi-link Protocol or MP.
5202 There is no default MRRU (Maximum Reconstructed Receive Unit) value.
5203 If no argument is given, multi-link mode is disabled.
5208 The default MRU (Maximum Receive Unit) is 1500.
5209 If it is increased, the other side *may* increase its MTU.
5210 In theory there is no point in decreasing the MRU to below the default as the
5212 protocol says implementations *must* be able to accept packets of at
5219 will refuse to negotiate a higher value.
5220 The maximum MRU can be set to 2048 at most.
5221 Setting a maximum of less than 1500 violates the
5223 rfc, but may sometimes be necessary.
5226 imposes a maximum of 1492 due to hardware limitations.
5228 If no argument is given, 1500 is assumed.
5229 A value must be given when
5236 The default MTU is 1500.
5237 At negotiation time,
5239 will accept whatever MRU the peer requests (assuming it is
5240 not less than 296 bytes or greater than the assigned maximum).
5243 will not accept MRU values less than
5245 When negotiations are complete, the MTU is used when writing to the
5246 interface, even if the peer requested a higher value MRU.
5247 This can be useful for
5248 limiting your packet size (giving better bandwidth sharing at the expense
5249 of more header data).
5255 will refuse to negotiate a higher value.
5256 The maximum MTU can be set to 2048 at most.
5257 Note, it is necessary to use the
5259 keyword to limit the MTU when using PPPoE.
5263 is given, 1500, or whatever the peer asks for is used.
5264 A value must be given when
5267 .It set nbns Op Ar x.x.x.x Op Ar y.y.y.y
5268 This option allows the setting of the Microsoft NetBIOS name server
5269 values to be returned at the peers request.
5270 If no values are given,
5272 will reject any such requests.
5273 .It set openmode active|passive Op Ar delay
5282 will always initiate LCP/IPCP/CCP negotiation one second after the line
5284 If you want to wait for the peer to initiate negotiations, you
5287 If you want to initiate negotiations immediately or after more than one
5288 second, the appropriate
5290 may be specified here in seconds.
5291 .It set parity odd|even|none|mark
5292 This allows the line parity to be set.
5293 The default value is
5295 .It set phone Ar telno Ns Xo
5296 .Oo \&| Ns Ar backupnumber Oc Ns ... Ns Oo : Ns Ar nextnumber Oc Ns ... Xc
5297 This allows the specification of the phone number to be used in
5298 place of the \\\\T string in the dial and login chat scripts.
5299 Multiple phone numbers may be given separated either by a pipe
5304 Numbers after the pipe are only dialed if the dial or login
5305 script for the previous number failed.
5307 Numbers after the colon are tried sequentially, irrespective of
5308 the reason the line was dropped.
5310 If multiple numbers are given,
5312 will dial them according to these rules until a connection is made, retrying
5313 the maximum number of times specified by
5318 mode, each number is attempted at most once.
5319 .It set pppoe Op standard|3Com
5320 This option configures the underlying
5322 node to either standard RFC2516 PPPoE or proprietary 3Com mode.
5323 If not set the system default will be used.
5324 .It set Oo proc Oc Ns Xo
5325 .No title Op Ar value
5327 The current process title as displayed by
5329 is changed according to
5333 is not specified, the original process title is restored.
5335 word replacements done by the shell commands (see the
5337 command above) are done here too.
5339 Note, if USER is required in the process title, the
5341 command must appear in
5343 as it is not known when the commands in
5346 .It set radius Op Ar config-file
5347 This command enables RADIUS support (if it is compiled in).
5349 refers to the radius client configuration file as described in
5351 If PAP, CHAP, MSCHAP or MSCHAPv2 are
5352 .Dq enable Ns No d ,
5355 .Em \&N Ns No etwork
5358 and uses the configured RADIUS server to authenticate rather than
5359 authenticating from the
5361 file or from the passwd database.
5363 If none of PAP, CHAP, MSCHAP or MSCHAPv2 are enabled,
5368 uses the following attributes from the RADIUS reply:
5369 .Bl -tag -width XXX -offset XXX
5370 .It RAD_FRAMED_IP_ADDRESS
5371 The peer IP address is set to the given value.
5372 .It RAD_FRAMED_IP_NETMASK
5373 The tun interface netmask is set to the given value.
5375 If the given MTU is less than the peers MRU as agreed during LCP
5376 negotiation, *and* it is less that any configured MTU (see the
5378 command), the tun interface MTU is set to the given value.
5379 .It RAD_FRAMED_COMPRESSION
5380 If the received compression type is
5383 will request VJ compression during IPCP negotiations despite any
5385 configuration command.
5387 If this attribute is supplied,
5389 will attempt to use it as an additional label to load from the
5394 The load will be attempted before (and in addition to) the normal
5396 If the label does not exist, no action is taken and
5398 proceeds to the normal load using the current label.
5399 .It RAD_FRAMED_ROUTE
5400 The received string is expected to be in the format
5401 .Ar dest Ns Op / Ns Ar bits
5404 Any specified metrics are ignored.
5408 are understood as valid values for
5415 to sepcify the default route, and
5417 is understood to be the same as
5426 For example, a returned value of
5427 .Dq 1.2.3.4/24 0.0.0.0 1 2 -1 3 400
5428 would result in a routing table entry to the 1.2.3.0/24 network via
5430 and a returned value of
5434 would result in a default route to
5437 All RADIUS routes are applied after any sticky routes are applied, making
5438 RADIUS routes override configured routes.
5439 This also applies for RADIUS routes that do not {include} the
5445 .It RAD_FRAMED_IPV6_PREFIX
5446 If this attribute is supplied, the value is substituted for IPV6PREFIX
5448 You may pass it to an upper layer protocol such as DHCPv6 for delegating an
5449 IPv6 prefix to a peer.
5450 .It RAD_FRAMED_IPV6_ROUTE
5451 The received string is expected to be in the format
5452 .Ar dest Ns Op / Ns Ar bits
5455 Any specified metrics are ignored.
5459 are understood as valid values for
5466 to sepcify the default route, and
5468 is understood to be the same as
5477 For example, a returned value of
5478 .Dq 3ffe:505:abcd::/48 ::
5479 would result in a routing table entry to the 3ffe:505:abcd::/48 network via
5481 and a returned value of
5484 .Dq default HISADDR6
5485 would result in a default route to
5488 All RADIUS IPv6 routes are applied after any sticky routes are
5489 applied, making RADIUS IPv6 routes override configured routes.
5491 also applies for RADIUS IPv6 routes that do not {include} the
5497 .It RAD_SESSION_TIMEOUT
5498 If supplied, the client connection is closed after the given number of
5500 .It RAD_REPLY_MESSAGE
5501 If supplied, this message is passed back to the peer as the authentication
5503 .It RAD_MICROSOFT_MS_CHAP_ERROR
5505 .Dv RAD_VENDOR_MICROSOFT
5506 vendor specific attribute is supplied, it is passed back to the peer as the
5507 authentication FAILURE text.
5508 .It RAD_MICROSOFT_MS_CHAP2_SUCCESS
5510 .Dv RAD_VENDOR_MICROSOFT
5511 vendor specific attribute is supplied and if MS-CHAPv2 authentication is
5512 being used, it is passed back to the peer as the authentication SUCCESS text.
5513 .It RAD_MICROSOFT_MS_MPPE_ENCRYPTION_POLICY
5515 .Dv RAD_VENDOR_MICROSOFT
5516 vendor specific attribute is supplied and has a value of 2 (Required),
5518 will insist that MPPE encryption is used (even if no
5520 configuration command has been given with arguments).
5521 If it is supplied with a value of 1 (Allowed), encryption is made optional
5524 configuration commands with arguments).
5525 .It RAD_MICROSOFT_MS_MPPE_ENCRYPTION_TYPES
5527 .Dv RAD_VENDOR_MICROSOFT
5528 vendor specific attribute is supplied, bits 1 and 2 are examined.
5529 If either or both are set, 40 bit and/or 128 bit (respectively) encryption
5530 options are set, overriding any given first argument to the
5533 Note, it is not currently possible for the RADIUS server to specify 56 bit
5535 .It RAD_MICROSOFT_MS_MPPE_RECV_KEY
5537 .Dv RAD_VENDOR_MICROSOFT
5538 vendor specific attribute is supplied, it is value is used as the master
5539 key for decryption of incoming data.
5540 When clients are authenticated using
5541 MSCHAPv2, the RADIUS server MUST provide this attribute if inbound MPPE is
5543 .It RAD_MICROSOFT_MS_MPPE_SEND_KEY
5545 .Dv RAD_VENDOR_MICROSOFT
5546 vendor specific attribute is supplied, it is value is used as the master
5547 key for encryption of outgoing data.
5548 When clients are authenticated using
5549 MSCHAPv2, the RADIUS server MUST provide this attribute if outbound MPPE is
5553 Values received from the RADIUS server may be viewed using
5555 .It set rad_alive Ar timeout
5556 When RADIUS is configured, setting
5562 to sent RADIUS accounting information to the RADIUS server every
5565 .It set rad_port_id Ar option
5566 When RADIUS is configured, setting the
5568 value allows to specify what should be sent to the RADIUS server as
5575 PID of the corresponding tunnel.
5580 index of the interface as returned by
5581 .Xr if_nametoindex 3 .
5583 keeps the default behavior.
5585 .It set reconnect Ar timeout ntries
5586 Should the line drop unexpectedly (due to loss of CD or LQR
5587 failure), a connection will be re-established after the given
5589 The line will be re-connected at most
5598 will result in a variable pause, somewhere between 1 and 30 seconds.
5599 .It set recvpipe Op Ar value
5600 This sets the routing table RECVPIPE value.
5601 The optimum value is just over twice the MTU value.
5604 is unspecified or zero, the default kernel controlled value is used.
5605 .It set redial Ar secs Ns Xo
5607 .Oo - Ns Ar max Ns Oc Oc Ns
5612 can be instructed to attempt to redial
5615 If more than one phone number is specified (see
5619 is taken before dialing each number.
5622 is taken before starting at the first number again.
5625 may be used here in place of
5629 causing a random delay of between 1 and 30 seconds.
5633 is specified, its value is added onto
5639 will only be incremented at most
5647 delay will be effective, even after
5649 has been exceeded, so an immediate manual dial may appear to have
5651 If an immediate dial is required, a
5653 should immediately follow the
5658 description above for further details.
5659 .It set sendpipe Op Ar value
5660 This sets the routing table SENDPIPE value.
5661 The optimum value is just over twice the MTU value.
5664 is unspecified or zero, the default kernel controlled value is used.
5665 .It "set server|socket" Ar TcpPort Ns No \&| Ns Xo
5666 .Ar LocalName Ns No |none|open|closed
5667 .Op password Op Ar mask
5671 to listen on the given socket or
5673 for incoming command connections.
5679 to close any existing socket and clear the socket configuration.
5684 to attempt to re-open the port.
5689 to close the open port.
5691 If you wish to specify a local domain socket,
5693 must be specified as an absolute file name, otherwise it is assumed
5694 to be the name or number of a TCP port.
5695 You may specify the octal umask to be used with a local domain socket.
5701 for details of how to translate TCP port names.
5703 You must also specify the password that must be entered by the client
5706 variable above) when connecting to this socket.
5708 specified as an empty string, no password is required for connecting clients.
5710 When specifying a local domain socket, the first
5712 sequence found in the socket name will be replaced with the current
5713 interface unit number.
5714 This is useful when you wish to use the same
5715 profile for more than one connection.
5717 In a similar manner TCP sockets may be prefixed with the
5719 character, in which case the current interface unit number is added to
5724 with a server socket, the
5726 command is the preferred mechanism of communications.
5729 can also be used, but link encryption may be implemented in the future, so
5737 interact with the diagnostic socket.
5738 .It set speed Ar value
5739 This sets the speed of the serial device.
5740 If speed is specified as
5743 treats the device as a synchronous device.
5745 Certain device types will know whether they should be specified as
5746 synchronous or asynchronous.
5747 These devices will override incorrect
5748 settings and log a warning to this effect.
5749 .It set stopped Op Ar LCPseconds Op Ar CCPseconds
5750 If this option is set,
5752 will time out after the given FSM (Finite State Machine) has been in
5753 the stopped state for the given number of
5755 This option may be useful if the peer sends a terminate request,
5756 but never actually closes the connection despite our sending a terminate
5758 This is also useful if you wish to
5759 .Dq set openmode passive
5760 and time out if the peer does not send a Configure Request within the
5763 .Dq set log +lcp +ccp
5766 log the appropriate state transitions.
5768 The default value is zero, where
5770 does not time out in the stopped state.
5772 This value should not be set to less than the openmode delay (see
5775 .It set timeout Ar idleseconds Op Ar mintimeout
5776 This command allows the setting of the idle timer.
5777 Refer to the section titled
5778 .Sx SETTING THE IDLE TIMER
5779 for further details.
5785 will never idle out before the link has been up for at least that number
5793 This command controls the ports that
5795 prioritizes when transmitting data.
5796 The default priority TCP ports
5797 are ports 21 (ftp control), 22 (ssh), 23 (telnet), 513 (login), 514 (shell),
5798 543 (klogin) and 544 (kshell).
5799 There are no priority UDP ports by default.
5814 are given, the priority port lists are cleared (although if
5818 is specified, only that list is cleared).
5821 argument is prefixed with a plus
5825 the current list is adjusted, otherwise the list is reassigned.
5827 prefixed with a plus or not prefixed at all are added to the list and
5829 prefixed with a minus are removed from the list.
5833 is specified, all priority port lists are disabled and even
5835 packets are not prioritised.
5836 .It set vj slotcomp on|off
5839 whether it should attempt to negotiate VJ slot compression.
5840 By default, slot compression is turned
5842 .It set vj slots Ar nslots
5843 This command sets the initial number of slots that
5845 will try to negotiate with the peer when VJ compression is enabled (see the
5848 It defaults to a value of 16.
5857 .It shell|! Op Ar command
5860 is not specified a shell is invoked according to the
5862 environment variable.
5863 Otherwise, the given
5866 Word replacement is done in the same way as for the
5868 command as described above.
5870 Use of the !\& character
5871 requires a following space as with any of the other commands.
5872 You should note that this command is executed in the foreground;
5874 will not continue running until this process has exited.
5877 command if you wish processing to happen in the background.
5879 This command allows the user to examine the following:
5882 Show the current bundle settings.
5884 Show the current CCP compression statistics.
5886 Show the current VJ compression statistics.
5888 Show the current escape characters.
5889 .It show filter Op Ar name
5890 List the current rules for the given filter.
5893 is not specified, all filters are shown.
5895 Show the current HDLC statistics.
5897 Give a summary of available show commands.
5899 Show the current interface information
5903 Show the current IPCP statistics.
5905 Show the protocol layers currently in use.
5907 Show the current LCP statistics.
5908 .It show Oo data Oc Ns Xo
5911 Show high level link information.
5913 Show a list of available logical links.
5915 Show the current log values.
5917 Show current memory statistics.
5919 Show the current NCP statistics.
5921 Show low level link information.
5923 Show Multi-link information.
5925 Show current protocol totals.
5927 Show the current routing tables.
5929 Show the current stopped timeouts.
5931 Show the active alarm timers.
5933 Show the current version number of
5938 Go into terminal mode.
5939 Characters typed at the keyboard are sent to the device.
5940 Characters read from the device are displayed on the screen.
5945 automatically enables Packet Mode and goes back into command mode.
5950 Read the example configuration files.
5951 They are a good source of information.
5960 to get online information about what is available.
5962 The following URLs contain useful information:
5963 .Bl -bullet -compact
5965 http://www.FreeBSD.org/doc/en_US.ISO8859-1/books/faq/ppp.html
5967 http://www.FreeBSD.org/doc/handbook/userppp.html
5973 refers to four files:
5979 These files are placed in the
5983 .It Pa /etc/ppp/ppp.conf
5984 System default configuration file.
5985 .It Pa /etc/ppp/ppp.secret
5986 An authorisation file for each system.
5987 .It Pa /etc/ppp/ppp.linkup
5988 A file to check when
5990 establishes a network level connection.
5991 .It Pa /etc/ppp/ppp.linkdown
5992 A file to check when
5994 closes a network level connection.
5995 .It Pa /var/log/ppp.log
5996 Logging and debugging information file.
5997 Note, this name is specified in
5998 .Pa /etc/syslog.conf .
6001 for further details.
6002 .It Pa /var/spool/lock/LCK..*
6003 tty port locking file.
6006 for further details.
6007 .It Pa /var/run/tunN.pid
6008 The process id (pid) of the
6010 program connected to the tunN device, where
6012 is the number of the device.
6013 .It Pa /var/run/ttyXX.if
6014 The tun interface used by this port.
6015 Again, this file is only created in
6021 .It Pa /etc/services
6022 Get port number if port number is using service name.
6023 .It Pa /var/run/ppp-authname-class-value
6024 In multi-link mode, local domain sockets are created using the peer
6027 the peer endpoint discriminator class
6029 and the peer endpoint discriminator value
6031 As the endpoint discriminator value may be a binary value, it is turned
6032 to HEX to determine the actual file name.
6034 This socket is used to pass links between different instances of
6076 This program was originally written by
6077 .An Toshiharu OHNO Aq tony-o@iij.ad.jp ,
6078 and was submitted to
6081 .An Atsushi Murai Aq amurai@spec.co.jp .
6083 It was substantially modified during 1997 by
6084 .An Brian Somers Aq brian@Awfulhak.org ,
6087 in November that year
6088 (just after the 2.2 release).
6090 Most of the code was rewritten by
6092 in early 1998 when multi-link ppp support was added.
projects / FreeBSD / releng / 10.0.git / blob