Preprocess ppp.8.m4 into ppp.8, taking into account any compile time

options used to build ppp.

Currently, this is a no-op and only handles LOCALNAT and LOCALRAD cases.

This will be used for the upcoming ipv6 changes, and allows a shared
man page between OpenBSD and FreeBSD.

3 files changed, 46 insertions, 5763 deletions

diff --git a/usr.sbin/ppp/Makefile b/usr.sbin/ppp/Makefile
index ccbe6a6c..74ec0b7 100644
--- a/usr.sbin/ppp/Makefile
+++ b/usr.sbin/ppp/Makefile
@@ -15,10 +15,16 @@ BINMODE=4554
 BINOWN=	root
 .endif
 BINGRP=	network
+M4FLAGS=
 
 LDADD= -lcrypt -lmd -lutil -lz
 DPADD=	${LIBCRYPT} ${LIBMD} ${LIBUTIL} ${LIBZ}
 
+.SUFFIXES: .8 .8.m4
+
+.8.m4.8:
+	m4 ${M4FLAGS} ${.IMPSRC} >${.TARGET}
+
 .if defined(RELEASE_CRUNCH)
 CFLAGS+=-DRELEASE_CRUNCH
 .endif
diff --git a/usr.sbin/ppp/ppp.8 b/usr.sbin/ppp/ppp.8
deleted file mode 100644
index 29e7681..0000000
--- a/usr.sbin/ppp/ppp.8
+++ /dev/null
@@ -1,5738 +0,0 @@
-.\"
-.\" Copyright (c) 2001 Brian Somers <brian@Awfulhak.org>
-.\" All rights reserved.
-.\"
-.\" Redistribution and use in source and binary forms, with or without
-.\" modification, are permitted provided that the following conditions
-.\" are met:
-.\" 1. Redistributions of source code must retain the above copyright
-.\"    notice, this list of conditions and the following disclaimer.
-.\" 2. Redistributions in binary form must reproduce the above copyright
-.\"    notice, this list of conditions and the following disclaimer in the
-.\"    documentation and/or other materials provided with the distribution.
-.\"
-.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
-.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
-.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-.\" SUCH DAMAGE.
-.\"
-.\" $FreeBSD$
-.\"
-.Dd September 20, 1995
-.Dt PPP 8
-.Os
-.Sh NAME
-.Nm ppp
-.Nd Point to Point Protocol (a.k.a. user-ppp)
-.Sh SYNOPSIS
-.Nm
-.Op Fl Va mode
-.Op Fl nat
-.Op Fl quiet
-.Op Fl unit Ns Ar N
-.Op Ar system ...
-.Sh DESCRIPTION
-This is a user process
-.Em PPP
-software package.
-Normally,
-.Em PPP
-is implemented as a part of the kernel (e.g., as managed by
-.Xr pppd 8 )
-and it's thus somewhat hard to debug and/or modify its behaviour.
-However, in this implementation
-.Em PPP
-is done as a user process with the help of the
-tunnel device driver (tun).
-.Pp
-The
-.Fl nat
-flag does the equivalent of a
-.Dq nat enable yes ,
-enabling
-.Nm Ns No 's
-network address translation features.
-This allows
-.Nm
-to act as a NAT or masquerading engine for all machines on an internal
-LAN.
-Refer to
-.Xr libalias 3
-for details.
-.Pp
-The
-.Fl quiet
-flag tells
-.Nm
-to be silent at startup rather than displaying the mode and interface
-to standard output.
-.Pp
-The
-.Fl unit
-flag tells
-.Nm
-to only attempt to open
-.Pa /dev/tun Ns Ar N .
-Normally,
-.Nm
-will start with a value of 0 for
-.Ar N ,
-and keep trying to open a tunnel device by incrementing the value of
-.Ar N
-by one each time until it succeeds.
-If it fails three times in a row
-because the device file is missing, it gives up.
-.Pp
-The following
-.Va mode Ns No s
-are understood by
-.Nm :
-.Bl -tag -width XXX -offset XXX
-.It Fl auto
-.Nm
-opens the tun interface, configures it then goes into the background.
-The link isn't brought up until outgoing data is detected on the tun
-interface at which point
-.Nm
-attempts to bring up the link.
-Packets received (including the first one) while
-.Nm
-is trying to bring the link up will remain queued for a default of
-2 minutes.
-See the
-.Dq set choked
-command below.
-.Pp
-In
-.Fl auto
-mode, at least one
-.Dq system
-must be given on the command line (see below) and a
-.Dq set ifaddr
-must be done in the system profile that specifies a peer IP address to
-use when configuring the interface.
-Something like
-.Dq 10.0.0.1/0
-is usually appropriate.
-See the
-.Dq pmdemand
-system in
-.Pa /usr/share/examples/ppp/ppp.conf.sample
-for an example.
-.It Fl background
-Here,
-.Nm
-attempts to establish a connection with the peer immediately.
-If it succeeds,
-.Nm
-goes into the background and the parent process returns an exit code
-of 0.
-If it fails,
-.Nm
-exits with a non-zero result.
-.It Fl foreground
-In foreground mode,
-.Nm
-attempts to establish a connection with the peer immediately, but never
-becomes a daemon.
-The link is created in background mode.
-This is useful if you wish to control
-.Nm Ns No 's
-invocation from another process.
-.It Fl direct
-This is used for receiving incoming connections.
-.Nm
-ignores the
-.Dq set device
-line and uses descriptor 0 as the link.
-.Pp
-If callback is configured,
-.Nm
-will use the
-.Dq set device
-information when dialing back.
-.It Fl dedicated
-This option is designed for machines connected with a dedicated
-wire.
-.Nm
-will always keep the device open and will never use any configured
-chat scripts.
-.It Fl ddial
-This mode is equivalent to
-.Fl auto
-mode except that
-.Nm
-will bring the link back up any time it's dropped for any reason.
-.It Fl interactive
-This is a no-op, and gives the same behaviour as if none of the above
-modes have been specified.
-.Nm
-loads any sections specified on the command line then provides an
-interactive prompt.
-.El
-.Pp
-One or more configuration entries or systems
-(as specified in
-.Pa /etc/ppp/ppp.conf )
-may also be specified on the command line.
-.Nm
-will read the
-.Dq default
-system from
-.Pa /etc/ppp/ppp.conf
-at startup, followed by each of the systems specified on the command line.
-.Sh Major Features
-.Bl -diag
-.It Provides an interactive user interface.
-Using its command mode, the user can
-easily enter commands to establish the connection with the remote end, check
-the status of connection and close the connection.
-All functions can also be optionally password protected for security.
-.It Supports both manual and automatic dialing.
-Interactive mode has a
-.Dq term
-command which enables you to talk to the device directly.
-When you are connected to the remote peer and it starts to talk
-.Em PPP ,
-.Nm
-detects it and switches to packet mode automatically.
-Once you have
-determined the proper sequence for connecting with the remote host, you
-can write a chat script to define the necessary dialing and login
-procedure for later convenience.
-.It Supports on-demand dialup capability.
-By using
-.Fl auto
-mode,
-.Nm
-will act as a daemon and wait for a packet to be sent over the
-.Em PPP
-link.
-When this happens, the daemon automatically dials and establishes the
-connection.
-In almost the same manner
-.Fl ddial
-mode (direct-dial mode) also automatically dials and establishes the
-connection.
-However, it differs in that it will dial the remote site
-any time it detects the link is down, even if there are no packets to be
-sent.
-This mode is useful for full-time connections where we worry less
-about line charges and more about being connected full time.
-A third
-.Fl dedicated
-mode is also available.
-This mode is targeted at a dedicated link between two machines.
-.Nm
-will never voluntarily quit from dedicated mode - you must send it the
-.Dq quit all
-command via its diagnostic socket.
-A
-.Dv SIGHUP
-will force an LCP renegotiation, and a
-.Dv SIGTERM
-will force it to exit.
-.It Supports client callback.
-.Nm
-can use either the standard LCP callback protocol or the Microsoft
-CallBack Control Protocol (ftp://ftp.microsoft.com/developr/rfc/cbcp.txt).
-.It Supports NAT or packet aliasing.
-Packet aliasing (a.k.a. IP masquerading) allows computers on a
-private, unregistered network to access the Internet.
-The
-.Em PPP
-host acts as a masquerading gateway.
-IP addresses as well as TCP and
-UDP port numbers are NAT'd for outgoing packets and de-NAT'd for
-returning packets.
-.It Supports background PPP connections.
-In background mode, if
-.Nm
-successfully establishes the connection, it will become a daemon.
-Otherwise, it will exit with an error.
-This allows the setup of
-scripts that wish to execute certain commands only if the connection
-is successfully established.
-.It Supports server-side PPP connections.
-In direct mode,
-.Nm
-acts as server which accepts incoming
-.Em PPP
-connections on stdin/stdout.
-.It "Supports PAP and CHAP (rfc 1994, 2433 and 2759) authentication.
-With PAP or CHAP, it is possible to skip the Unix style
-.Xr login 1
-procedure, and use the
-.Em PPP
-protocol for authentication instead.
-If the peer requests Microsoft CHAP authentication and
-.Nm
-is compiled with DES support, an appropriate MD4/DES response will be
-made.
-.It Supports RADIUS (rfc 2138) authentication.
-An extension to PAP and CHAP,
-.Em \&R Ns No emote
-.Em \&A Ns No ccess
-.Em \&D Ns No ial
-.Em \&I Ns No n
-.Em \&U Ns No ser
-.Em \&S Ns No ervice
-allows authentication information to be stored in a central or
-distributed database along with various per-user framed connection
-characteristics.
-If
-.Pa libradius
-is available at compile time,
-.Nm
-will use it to make
-.Em RADIUS
-requests when configured to do so.
-.It Supports Proxy Arp.
-.Nm
-can be configured to make one or more proxy arp entries on behalf of
-the peer.
-This allows routing from the peer to the LAN without
-configuring each machine on that LAN.
-.It Supports packet filtering.
-User can define four kinds of filters: the
-.Em in
-filter for incoming packets, the
-.Em out
-filter for outgoing packets, the
-.Em dial
-filter to define a dialing trigger packet and the
-.Em alive
-filter for keeping a connection alive with the trigger packet.
-.It Tunnel driver supports bpf.
-The user can use
-.Xr tcpdump 1
-to check the packet flow over the
-.Em PPP
-link.
-.It Supports PPP over TCP and PPP over UDP.
-If a device name is specified as
-.Em host Ns No : Ns Em port Ns
-.Xo
-.Op / Ns tcp|udp ,
-.Xc
-.Nm
-will open a TCP or UDP connection for transporting data rather than using a
-conventional serial device.
-UDP connections force
-.Nm
-into synchronous mode.
-.It Supports PPP over ISDN.
-If
-.Nm
-is given a raw B-channel i4b device to open as a link, it's able to talk
-to the
-.Xr isdnd 8
-daemon to establish an ISDN connection.
-.It Supports PPP over Ethernet (rfc 2516).
-If
-.Nm
-is given a device specification of the format
-.No PPPoE: Ns Ar iface Ns Xo
-.Op \&: Ns Ar provider Ns
-.Xc
-and if
-.Xr netgraph 4
-is available,
-.Nm
-will attempt talk
-.Em PPP
-over Ethernet to
-.Ar provider
-using the
-.Ar iface
-network interface.
-.Pp
-On systems that do not support
-.Xr netgraph 4 ,
-an external program such as
-.Xr pppoe 8
-may be used.
-.It "Supports IETF draft Predictor-1 (rfc 1978) and DEFLATE (rfc 1979) compression."
-.Nm
-supports not only VJ-compression but also Predictor-1 and DEFLATE compression.
-Normally, a modem has built-in compression (e.g., v42.bis) and the system
-may receive higher data rates from it as a result of such compression.
-While this is generally a good thing in most other situations, this
-higher speed data imposes a penalty on the system by increasing the
-number of serial interrupts the system has to process in talking to the
-modem and also increases latency.
-Unlike VJ-compression, Predictor-1 and DEFLATE compression pre-compresses
-.Em all
-network traffic flowing through the link, thus reducing overheads to a
-minimum.
-.It Supports Microsoft's IPCP extensions (rfc 1877).
-Name Server Addresses and NetBIOS Name Server Addresses can be negotiated
-with clients using the Microsoft
-.Em PPP
-stack (i.e., Win95, WinNT)
-.It Supports Multi-link PPP (rfc 1990)
-It is possible to configure
-.Nm
-to open more than one physical connection to the peer, combining the
-bandwidth of all links for better throughput.
-.It Supports MPPE (draft-ietf-pppext-mppe)
-MPPE is Microsoft Point to Point Encryption scheme.
-It is possible to configure
-.Nm
-to participate in Microsoft's Windows VPN.
-For now,
-.Nm
-can only get encryption keys from CHAP 81 authentication.
-.Nm
-must be compiled with DES for MPPE to operate.
-.El
-.Sh PERMISSIONS
-.Nm
-is installed as user
-.Dv root
-and group
-.Dv network ,
-with permissions
-.Dv 04554 .
-By default,
-.Nm
-will not run if the invoking user id is not zero.
-This may be overridden by using the
-.Dq allow users
-command in
-.Pa /etc/ppp/ppp.conf .
-When running as a normal user,
-.Nm
-switches to user id 0 in order to alter the system routing table, set up
-system lock files and read the ppp configuration files.
-All external commands (executed via the "shell" or "!bg" commands) are executed
-as the user id that invoked
-.Nm .
-Refer to the
-.Sq ID0
-logging facility if you're interested in what exactly is done as user id
-zero.
-.Sh GETTING STARTED
-When you first run
-.Nm
-you may need to deal with some initial configuration details.
-.Bl -bullet
-.It
-Your kernel must include a tunnel device (the GENERIC kernel includes
-one by default).
-If it doesn't, or if you require more than one tun
-interface, you'll need to rebuild your kernel with the following line in
-your kernel configuration file:
-.Pp
-.Dl pseudo-device tun N
-.Pp
-where
-.Ar N
-is the maximum number of
-.Em PPP
-connections you wish to support.
-.It
-Check your
-.Pa /dev
-directory for the tunnel device entries
-.Pa /dev/tunN ,
-where
-.Sq N
-represents the number of the tun device, starting at zero.
-If they don't exist, you can create them by running "sh ./MAKEDEV tunN".
-This will create tun devices 0 through
-.Ar N .
-.It
-Make sure that your system has a group named
-.Dq network
-in the
-.Pa /etc/group
-file and that the group contains the names of all users expected to use
-.Nm .
-Refer to the
-.Xr group 5
-manual page for details.
-Each of these users must also be given access using the
-.Dq allow users
-command in
-.Pa /etc/ppp/ppp.conf .
-.It
-Create a log file.
-.Nm
-uses
-.Xr syslog 3
-to log information.
-A common log file name is
-.Pa /var/log/ppp.log .
-To make output go to this file, put the following lines in the
-.Pa /etc/syslog.conf
-file:
-.Bd -literal -offset indent
-!ppp
-*.*<TAB>/var/log/ppp.log
-.Ed
-.Pp
-It is possible to have more than one
-.Em PPP
-log file by creating a link to the
-.Nm
-executable:
-.Pp
-.Dl # cd /usr/sbin
-.Dl # ln ppp ppp0
-.Pp
-and using
-.Bd -literal -offset indent
-!ppp0
-*.*<TAB>/var/log/ppp0.log
-.Ed
-.Pp
-in
-.Pa /etc/syslog.conf .
-Don't forget to send a
-.Dv HUP
-signal to
-.Xr syslogd 8
-after altering
-.Pa /etc/syslog.conf .
-.It
-Although not strictly relevant to
-.Nm Ns No 's
-operation, you should configure your resolver so that it works correctly.
-This can be done by configuring a local DNS
-(using
-.Xr named 8 )
-or by adding the correct
-.Sq nameserver
-lines to the file
-.Pa /etc/resolv.conf .
-Refer to the
-.Xr resolv.conf 5
-manual page for details.
-.Pp
-Alternatively, if the peer supports it,
-.Nm
-can be configured to ask the peer for the nameserver address(es) and to
-update
-.Pa /etc/resolv.conf
-automatically.
-Refer to the
-.Dq enable dns
-and
-.Dq resolv
-commands below for details.
-.El
-.Sh MANUAL DIALING
-In the following examples, we assume that your machine name is
-.Dv awfulhak .
-when you invoke
-.Nm
-(see
-.Sx PERMISSIONS
-above) with no arguments, you are presented with a prompt:
-.Bd -literal -offset indent
-ppp ON awfulhak>
-.Ed
-.Pp
-The
-.Sq ON
-part of your prompt should always be in upper case.
-If it is in lower case, it means that you must supply a password using the
-.Dq passwd
-command.
-This only ever happens if you connect to a running version of
-.Nm
-and have not authenticated yourself using the correct password.
-.Pp
-You can start by specifying the device name and speed:
-.Bd -literal -offset indent
-ppp ON awfulhak> set device /dev/cuaa0
-ppp ON awfulhak> set speed 38400
-.Ed
-.Pp
-Normally, hardware flow control (CTS/RTS) is used.
-However, under
-certain circumstances (as may happen when you are connected directly
-to certain PPP-capable terminal servers), this may result in
-.Nm
-hanging as soon as it tries to write data to your communications link
-as it is waiting for the CTS (clear to send) signal - which will never
-come.
-Thus, if you have a direct line and can't seem to make a
-connection, try turning CTS/RTS off with
-.Dq set ctsrts off .
-If you need to do this, check the
-.Dq set accmap
-description below too - you'll probably need to
-.Dq set accmap 000a0000 .
-.Pp
-Usually, parity is set to
-.Dq none ,
-and this is
-.Nm Ns No 's
-default.
-Parity is a rather archaic error checking mechanism that is no
-longer used because modern modems do their own error checking, and most
-link-layer protocols (that's what
-.Nm
-is) use much more reliable checking mechanisms.
-Parity has a relatively
-huge overhead (a 12.5% increase in traffic) and as a result, it is always
-disabled
-(set to
-.Dq none )
-when
-.Dv PPP
-is opened.
-However, some ISPs (Internet Service Providers) may use
-specific parity settings at connection time (before
-.Dv PPP
-is opened).
-Notably, Compuserve insist on even parity when logging in:
-.Bd -literal -offset indent
-ppp ON awfulhak> set parity even
-.Ed
-.Pp
-You can now see what your current device settings look like:
-.Bd -literal -offset indent
-ppp ON awfulhak> show physical
-Name: deflink
- State:           closed
- Device:          N/A
- Link Type:       interactive
- Connect Count:   0
- Queued Packets:  0
- Phone Number:    N/A
-
-Defaults:
- Device List:     /dev/cuaa0
- Characteristics: 38400bps, cs8, even parity, CTS/RTS on
-
-Connect time: 0 secs
-0 octets in, 0 octets out
-Overall 0 bytes/sec
-ppp ON awfulhak>
-.Ed
-.Pp
-The term command can now be used to talk directly to the device:
-.Bd -literal -offset indent
-ppp ON awfulhak> term
-at
-OK
-atdt123456
-CONNECT
-login: myispusername
-Password: myisppassword
-Protocol: ppp
-.Ed
-.Pp
-When the peer starts to talk in
-.Em PPP ,
-.Nm
-detects this automatically and returns to command mode.
-.Bd -literal -offset indent
-ppp ON awfulhak>               # No link has been established
-Ppp ON awfulhak>               # We've connected & finished LCP
-PPp ON awfulhak>               # We've authenticated
-PPP ON awfulhak>               # We've agreed IP numbers
-.Ed
-.Pp
-If it does not, it's probable that the peer is waiting for your end to
-start negotiating.
-To force
-.Nm
-to start sending
-.Em PPP
-configuration packets to the peer, use the
-.Dq ~p
-command to drop out of terminal mode and enter packet mode.
-.Pp
-If you never even receive a login prompt, it is quite likely that the
-peer wants to use PAP or CHAP authentication instead of using Unix-style
-login/password authentication.
-To set things up properly, drop back to
-the prompt and set your authentication name and key, then reconnect:
-.Bd -literal -offset indent
-~.
-ppp ON awfulhak> set authname myispusername
-ppp ON awfulhak> set authkey myisppassword
-ppp ON awfulhak> term
-at
-OK
-atdt123456
-CONNECT
-.Ed
-.Pp
-You may need to tell ppp to initiate negotiations with the peer here too:
-.Bd -literal -offset indent
-~p
-ppp ON awfulhak>               # No link has been established
-Ppp ON awfulhak>               # We've connected & finished LCP
-PPp ON awfulhak>               # We've authenticated
-PPP ON awfulhak>               # We've agreed IP numbers
-.Ed
-.Pp
-You are now connected!
-Note that
-.Sq PPP
-in the prompt has changed to capital letters to indicate that you have
-a peer connection.
-If only some of the three Ps go uppercase, wait until
-either everything is uppercase or lowercase.
-If they revert to lowercase, it means that
-.Nm
-couldn't successfully negotiate with the peer.
-A good first step for troubleshooting at this point would be to
-.Bd -literal -offset indent
-ppp ON awfulhak> set log local phase lcp ipcp
-.Ed
-.Pp
-and try again.
-Refer to the
-.Dq set log
-command description below for further details.
-If things fail at this point,
-it is quite important that you turn logging on and try again.
-It is also
-important that you note any prompt changes and report them to anyone trying
-to help you.
-.Pp
-When the link is established, the show command can be used to see how
-things are going:
-.Bd -literal -offset indent
-PPP ON awfulhak> show physical
-* Modem related information is shown here *
-PPP ON awfulhak> show ccp
-* CCP (compression) related information is shown here *
-PPP ON awfulhak> show lcp
-* LCP (line control) related information is shown here *
-PPP ON awfulhak> show ipcp
-* IPCP (IP) related information is shown here *
-PPP ON awfulhak> show link
-* Link (high level) related information is shown here *
-PPP ON awfulhak> show bundle
-* Logical (high level) connection related information is shown here *
-.Ed
-.Pp
-At this point, your machine has a host route to the peer.
-This means
-that you can only make a connection with the host on the other side
-of the link.
-If you want to add a default route entry (telling your
-machine to send all packets without another routing entry to the other
-side of the
-.Em PPP
-link), enter the following command:
-.Bd -literal -offset indent
-PPP ON awfulhak> add default HISADDR
-.Ed
-.Pp
-The string
-.Sq HISADDR
-represents the IP address of the connected peer.
-If the
-.Dq add
-command fails due to an existing route, you can overwrite the existing
-route using
-.Bd -literal -offset indent
-PPP ON awfulhak> add! default HISADDR
-.Ed
-.Pp
-This command can also be executed before actually making the connection.
-If a new IP address is negotiated at connection time,
-.Nm
-will update your default route accordingly.
-.Pp
-You can now use your network applications (ping, telnet, ftp etc.)
-in other windows or terminals on your machine.
-If you wish to reuse the current terminal, you can put
-.Nm
-into the background using your standard shell suspend and background
-commands (usually
-.Dq ^Z
-followed by
-.Dq bg ) .
-.Pp
-Refer to the
-.Sx PPP COMMAND LIST
-section for details on all available commands.
-.Sh AUTOMATIC DIALING
-To use automatic dialing, you must prepare some Dial and Login chat scripts.
-See the example definitions in
-.Pa /usr/share/examples/ppp/ppp.conf.sample
-(the format of
-.Pa /etc/ppp/ppp.conf
-is pretty simple).
-Each line contains one comment, inclusion, label or command:
-.Bl -bullet
-.It
-A line starting with a
-.Pq Dq #
-character is treated as a comment line.
-Leading whitespace are ignored when identifying comment lines.
-.It
-An inclusion is a line beginning with the word
-.Sq !include .
-It must have one argument - the file to include.
-You may wish to
-.Dq !include ~/.ppp.conf
-for compatibility with older versions of
-.Nm .
-.It
-A label name starts in the first column and is followed by
-a colon
-.Pq Dq \&: .
-.It
-A command line must contain a space or tab in the first column.
-.El
-.Pp
-The
-.Pa /etc/ppp/ppp.conf
-file should consist of at least a
-.Dq default
-section.
-This section is always executed.
-It should also contain
-one or more sections, named according to their purpose, for example,
-.Dq MyISP
-would represent your ISP, and
-.Dq ppp-in
-would represent an incoming
-.Nm
-configuration.
-You can now specify the destination label name when you invoke
-.Nm .
-Commands associated with the
-.Dq default
-label are executed, followed by those associated with the destination
-label provided.
-When
-.Nm
-is started with no arguments, the
-.Dq default
-section is still executed.
-The load command can be used to manually load a section from the
-.Pa /etc/ppp/ppp.conf
-file:
-.Bd -literal -offset indent
-ppp ON awfulhak> load MyISP
-.Ed
-.Pp
-Note, no action is taken by
-.Nm
-after a section is loaded, whether it's the result of passing a label on
-the command line or using the
-.Dq load
-command.
-Only the commands specified for that label in the configuration
-file are executed.
-However, when invoking
-.Nm
-with the
-.Fl background ,
-.Fl ddial ,
-or
-.Fl dedicated
-switches, the link mode tells
-.Nm
-to establish a connection.
-Refer to the
-.Dq set mode
-command below for further details.
-.Pp
-Once the connection is made, the
-.Sq ppp
-portion of the prompt will change to
-.Sq PPP :
-.Bd -literal -offset indent
-# ppp MyISP
-\&...
-ppp ON awfulhak> dial
-Ppp ON awfulhak>
-PPp ON awfulhak>
-PPP ON awfulhak>
-.Ed
-.Pp
-The Ppp prompt indicates that
-.Nm
-has entered the authentication phase.
-The PPp prompt indicates that
-.Nm
-has entered the network phase.
-The PPP prompt indicates that
-.Nm
-has successfully negotiated a network layer protocol and is in
-a usable state.
-.Pp
-If the
-.Pa /etc/ppp/ppp.linkup
-file is available, its contents are executed
-when the
-.Em PPP
-connection is established.
-See the provided
-.Dq pmdemand
-example in
-.Pa /usr/share/examples/ppp/ppp.conf.sample
-which runs a script in the background after the connection is established
-(refer to the
-.Dq shell
-and
-.Dq bg
-commands below for a description of possible substitution strings).
-Similarly, when a connection is closed, the contents of the
-.Pa /etc/ppp/ppp.linkdown
-file are executed.
-Both of these files have the same format as
-.Pa /etc/ppp/ppp.conf .
-.Pp
-In previous versions of
-.Nm ,
-it was necessary to re-add routes such as the default route in the
-.Pa ppp.linkup
-file.
-.Nm
-now supports
-.Sq sticky routes ,
-where all routes that contain the
-.Dv HISADDR
-or
-.Dv MYADDR
-literals will automatically be updated when the values of
-.Dv HISADDR
-and/or
-.Dv MYADDR
-change.
-.Sh BACKGROUND DIALING
-If you want to establish a connection using
-.Nm
-non-interactively (such as from a
-.Xr crontab 5
-entry or an
-.Xr at 1
-job) you should use the
-.Fl background
-option.
-When
-.Fl background
-is specified,
-.Nm
-attempts to establish the connection immediately.
-If multiple phone
-numbers are specified, each phone number will be tried once.
-If the attempt fails,
-.Nm
-exits immediately with a non-zero exit code.
-If it succeeds, then
-.Nm
-becomes a daemon, and returns an exit status of zero to its caller.
-The daemon exits automatically if the connection is dropped by the
-remote system, or it receives a
-.Dv TERM
-signal.
-.Sh DIAL ON DEMAND
-Demand dialing is enabled with the
-.Fl auto
-or
-.Fl ddial
-options.
-You must also specify the destination label in
-.Pa /etc/ppp/ppp.conf
-to use.
-It must contain the
-.Dq set ifaddr
-command to define the remote peers IP address.
-(refer to
-.Pa /usr/share/examples/ppp/ppp.conf.sample )
-.Bd -literal -offset indent
-# ppp -auto pmdemand
-.Ed
-.Pp
-When
-.Fl auto
-or
-.Fl ddial
-is specified,
-.Nm
-runs as a daemon but you can still configure or examine its
-configuration by using the
-.Dq set server
-command in
-.Pa /etc/ppp/ppp.conf ,
-(for example,
-.Dq Li "set server +3000 mypasswd" )
-and connecting to the diagnostic port as follows:
-.Bd -literal -offset indent
-# pppctl 3000	(assuming tun0)
-Password:
-PPP ON awfulhak> show who
-tcp (127.0.0.1:1028) *
-.Ed
-.Pp
-The
-.Dq show who
-command lists users that are currently connected to
-.Nm
-itself.
-If the diagnostic socket is closed or changed to a different
-socket, all connections are immediately dropped.
-.Pp
-In
-.Fl auto
-mode, when an outgoing packet is detected,
-.Nm
-will perform the dialing action (chat script) and try to connect
-with the peer.
-In
-.Fl ddial
-mode, the dialing action is performed any time the line is found
-to be down.
-If the connect fails, the default behaviour is to wait 30 seconds
-and then attempt to connect when another outgoing packet is detected.
-This behaviour can be changed using the
-.Dq set redial
-command:
-.Pp
-.No set redial Ar secs Ns Xo
-.Oo + Ns Ar inc Ns
-.Op - Ns Ar max Ns
-.Oc Ns Op . Ns Ar next
-.Op Ar attempts
-.Xc
-.Pp
-.Bl -tag -width attempts -compact
-.It Ar secs
-is the number of seconds to wait before attempting
-to connect again.
-If the argument is the literal string
-.Sq Li random ,
-the delay period is a random value between 1 and 30 seconds inclusive.
-.It Ar inc
-is the number of seconds that
-.Ar secs
-should be incremented each time a new dial attempt is made.
-The timeout reverts to
-.Ar secs
-only after a successful connection is established.
-The default value for
-.Ar inc
-is zero.
-.It Ar max
-is the maximum number of times
-.Nm
-should increment
-.Ar secs .
-The default value for
-.Ar max
-is 10.
-.It Ar next
-is the number of seconds to wait before attempting
-to dial the next number in a list of numbers (see the
-.Dq set phone
-command).
-The default is 3 seconds.
-Again, if the argument is the literal string
-.Sq Li random ,
-the delay period is a random value between 1 and 30 seconds.
-.It Ar attempts
-is the maximum number of times to try to connect for each outgoing packet
-that triggers a dial.
-The previous value is unchanged if this parameter is omitted.
-If a value of zero is specified for
-.Ar attempts ,
-.Nm
-will keep trying until a connection is made.
-.El
-.Pp
-So, for example:
-.Bd -literal -offset indent
-set redial 10.3 4
-.Ed
-.Pp
-will attempt to connect 4 times for each outgoing packet that causes
-a dial attempt with a 3 second delay between each number and a 10 second
-delay after all numbers have been tried.
-If multiple phone numbers
-are specified, the total number of attempts is still 4 (it does not
-attempt each number 4 times).
-.Pp
-Alternatively,
-.Pp
-.Bd -literal -offset indent
-set redial 10+10-5.3 20
-.Ed
-.Pp
-tells
-.Nm
-to attempt to connect 20 times.
-After the first attempt,
-.Nm
-pauses for 10 seconds.
-After the next attempt it pauses for 20 seconds
-and so on until after the sixth attempt it pauses for 1 minute.
-The next 14 pauses will also have a duration of one minute.
-If
-.Nm
-connects, disconnects and fails to connect again, the timeout starts again
-at 10 seconds.
-.Pp
-Modifying the dial delay is very useful when running
-.Nm
-in
-.Fl auto
-mode on both ends of the link.
-If each end has the same timeout,
-both ends wind up calling each other at the same time if the link
-drops and both ends have packets queued.
-At some locations, the serial link may not be reliable, and carrier
-may be lost at inappropriate times.
-It is possible to have
-.Nm
-redial should carrier be unexpectedly lost during a session.
-.Bd -literal -offset indent
-set reconnect timeout ntries
-.Ed
-.Pp
-This command tells
-.Nm
-to re-establish the connection
-.Ar ntries
-times on loss of carrier with a pause of
-.Ar timeout
-seconds before each try.
-For example,
-.Bd -literal -offset indent
-set reconnect 3 5
-.Ed
-.Pp
-tells
-.Nm
-that on an unexpected loss of carrier, it should wait
-.Ar 3
-seconds before attempting to reconnect.
-This may happen up to
-.Ar 5
-times before
-.Nm
-gives up.
-The default value of ntries is zero (no reconnect).
-Care should be taken with this option.
-If the local timeout is slightly
-longer than the remote timeout, the reconnect feature will always be
-triggered (up to the given number of times) after the remote side
-times out and hangs up.
-NOTE: In this context, losing too many LQRs constitutes a loss of
-carrier and will trigger a reconnect.
-If the
-.Fl background
-flag is specified, all phone numbers are dialed at most once until
-a connection is made.
-The next number redial period specified with the
-.Dq set redial
-command is honoured, as is the reconnect tries value.
-If your redial
-value is less than the number of phone numbers specified, not all
-the specified numbers will be tried.
-To terminate the program, type
-.Bd -literal -offset indent
-PPP ON awfulhak> close
-ppp ON awfulhak> quit all
-.Ed
-.Pp
-A simple
-.Dq quit
-command will terminate the
-.Xr pppctl 8
-or
-.Xr telnet 1
-connection but not the
-.Nm
-program itself.
-You must use
-.Dq quit all
-to terminate
-.Nm
-as well.
-.Sh RECEIVING INCOMING PPP CONNECTIONS (Method 1)
-To handle an incoming
-.Em PPP
-connection request, follow these steps:
-.Bl -enum
-.It
-Make sure the modem and (optionally)
-.Pa /etc/rc.serial
-is configured correctly.
-.Bl -bullet -compact
-.It
-Use Hardware Handshake (CTS/RTS) for flow control.
-.It
-Modem should be set to NO echo back (ATE0) and NO results string (ATQ1).
-.El
-.Pp
-.It
-Edit
-.Pa /etc/ttys
-to enable a
-.Xr getty 8
-on the port where the modem is attached.
-For example:
-.Pp
-.Dl ttyd1 Qo /usr/libexec/getty std.38400 Qc dialup on secure
-.Pp
-Don't forget to send a
-.Dv HUP
-signal to the
-.Xr init 8
-process to start the
-.Xr getty 8 :
-.Pp
-.Dl # kill -HUP 1
-.Pp
-It is usually also necessary to train your modem to the same DTR speed
-as the getty:
-.Bd -literal -offset indent
-# ppp
-ppp ON awfulhak> set device /dev/cuaa1
-ppp ON awfulhak> set speed 38400
-ppp ON awfulhak> term
-deflink: Entering terminal mode on /dev/cuaa1
-Type `~?' for help
-at
-OK
-at
-OK
-atz
-OK
-at
-OK
-~.
-ppp ON awfulhak> quit
-.Ed
-.It
-Create a
-.Pa /usr/local/bin/ppplogin
-file with the following contents:
-.Bd -literal -offset indent
-#! /bin/sh
-exec /usr/sbin/ppp -direct incoming
-.Ed
-.Pp
-Direct mode
-.Pq Fl direct
-lets
-.Nm
-work with stdin and stdout.
-You can also use
-.Xr pppctl 8
-to connect to a configured diagnostic port, in the same manner as with
-client-side
-.Nm .
-.Pp
-Here, the
-.Ar incoming
-section must be set up in
-.Pa /etc/ppp/ppp.conf .
-.Pp
-Make sure that the
-.Ar incoming
-section contains the
-.Dq allow users
-command as appropriate.
-.It
-Prepare an account for the incoming user.
-.Bd -literal
-ppp:xxxx:66:66:PPP Login User:/home/ppp:/usr/local/bin/ppplogin
-.Ed
-.Pp
-Refer to the manual entries for
-.Xr adduser 8
-and
-.Xr vipw 8
-for details.
-.It
-Support for IPCP Domain Name Server and NetBIOS Name Server negotiation
-can be enabled using the
-.Dq accept dns
-and
-.Dq set nbns
-commands.
-Refer to their descriptions below.
-.El
-.Sh RECEIVING INCOMING PPP CONNECTIONS (Method 2)
-This method differs in that we use
-.Nm
-to authenticate the connection rather than
-.Xr login 1 :
-.Bl -enum
-.It
-Configure your default section in
-.Pa /etc/gettytab
-with automatic ppp recognition by specifying the
-.Dq pp
-capability:
-.Bd -literal
-default:\\
-	:pp=/usr/local/bin/ppplogin:\\
-	.....
-.Ed
-.It
-Configure your serial device(s), enable a
-.Xr getty 8
-and create
-.Pa /usr/local/bin/ppplogin
-as in the first three steps for method 1 above.
-.It
-Add either
-.Dq enable chap
-or
-.Dq enable pap
-(or both)
-to
-.Pa /etc/ppp/ppp.conf
-under the
-.Sq incoming
-label (or whatever label
-.Pa ppplogin
-uses).
-.It
-Create an entry in
-.Pa /etc/ppp/ppp.secret
-for each incoming user:
-.Bd -literal
-Pfred<TAB>xxxx
-Pgeorge<TAB>yyyy
-.Ed
-.El
-.Pp
-Now, as soon as
-.Xr getty 8
-detects a ppp connection (by recognising the HDLC frame headers), it runs
-.Dq /usr/local/bin/ppplogin .
-.Pp
-It is
-.Em VITAL
-that either PAP or CHAP are enabled as above.
-If they are not, you are
-allowing anybody to establish ppp session with your machine
-.Em without
-a password, opening yourself up to all sorts of potential attacks.
-.Sh AUTHENTICATING INCOMING CONNECTIONS
-Normally, the receiver of a connection requires that the peer
-authenticates itself.
-This may be done using
-.Xr login 1 ,
-but alternatively, you can use PAP or CHAP.
-CHAP is the more secure of the two, but some clients may not support it.
-Once you decide which you wish to use, add the command
-.Sq enable chap
-or
-.Sq enable pap
-to the relevant section of
-.Pa ppp.conf .
-.Pp
-You must then configure the
-.Pa /etc/ppp/ppp.secret
-file.
-This file contains one line per possible client, each line
-containing up to five fields:
-.Pp
-.Ar name Ar key Oo
-.Ar hisaddr Op Ar label Op Ar callback-number
-.Oc
-.Pp
-The
-.Ar name
-and
-.Ar key
-specify the client username and password.
-If
-.Ar key
-is
-.Dq \&*
-and PAP is being used,
-.Nm
-will look up the password database
-.Pq Xr passwd 5
-when authenticating.
-If the client does not offer a suitable response based on any
-.Ar name Ns No / Ns Ar key
-combination in
-.Pa ppp.secret ,
-authentication fails.
-.Pp
-If authentication is successful,
-.Ar hisaddr
-(if specified)
-is used when negotiating IP numbers.
-See the
-.Dq set ifaddr
-command for details.
-.Pp
-If authentication is successful and
-.Ar label
-is specified, the current system label is changed to match the given
-.Ar label .
-This will change the subsequent parsing of the
-.Pa ppp.linkup
-and
-.Pa ppp.linkdown
-files.
-.Pp
-If authentication is successful and
-.Ar callback-number
-is specified and
-.Dq set callback
-has been used in
-.Pa ppp.conf ,
-the client will be called back on the given number.
-If CBCP is being used,
-.Ar callback-number
-may also contain a list of numbers or a
-.Dq \&* ,
-as if passed to the
-.Dq set cbcp
-command.
-The value will be used in
-.Nm Ns No 's
-subsequent CBCP phase.
-.Sh PPP OVER TCP and UDP (a.k.a Tunnelling)
-Instead of running
-.Nm
-over a serial link, it is possible to
-use a TCP connection instead by specifying the host, port and protocol as the
-device:
-.Pp
-.Dl set device ui-gate:6669/tcp
-.Pp
-Instead of opening a serial device,
-.Nm
-will open a TCP connection to the given machine on the given
-socket.
-It should be noted however that
-.Nm
-doesn't use the telnet protocol and will be unable to negotiate
-with a telnet server.
-You should set up a port for receiving this
-.Em PPP
-connection on the receiving machine (ui-gate).
-This is done by first updating
-.Pa /etc/services
-to name the service:
-.Pp
-.Dl ppp-in 6669/tcp # Incoming PPP connections over TCP
-.Pp
-and updating
-.Pa /etc/inetd.conf
-to tell
-.Xr inetd 8
-how to deal with incoming connections on that port:
-.Pp
-.Dl ppp-in stream tcp nowait root /usr/sbin/ppp ppp -direct ppp-in
-.Pp
-Don't forget to send a
-.Dv HUP
-signal to
-.Xr inetd 8
-after you've updated
-.Pa /etc/inetd.conf .
-Here, we use a label named
-.Dq ppp-in .
-The entry in
-.Pa /etc/ppp/ppp.conf
-on ui-gate (the receiver) should contain the following:
-.Bd -literal -offset indent
-ppp-in:
- set timeout 0
- set ifaddr 10.0.4.1 10.0.4.2
-.Ed
-.Pp
-and the entry in
-.Pa /etc/ppp/ppp.linkup
-should contain:
-.Bd -literal -offset indent
-ppp-in:
- add 10.0.1.0/24 HISADDR
-.Ed
-.Pp
-It is necessary to put the
-.Dq add
-command in
-.Pa ppp.linkup
-to ensure that the route is only added after
-.Nm
-has negotiated and assigned addresses to its interface.
-.Pp
-You may also want to enable PAP or CHAP for security.
-To enable PAP, add the following line:
-.Bd -literal -offset indent
- enable PAP
-.Ed
-.Pp
-You'll also need to create the following entry in
-.Pa /etc/ppp/ppp.secret :
-.Bd -literal -offset indent
-MyAuthName MyAuthPasswd
-.Ed
-.Pp
-If
-.Ar MyAuthPasswd
-is a
-.Dq * ,
-the password is looked up in the
-.Xr passwd 5
-database.
-.Pp
-The entry in
-.Pa /etc/ppp/ppp.conf
-on awfulhak (the initiator) should contain the following:
-.Bd -literal -offset indent
-ui-gate:
- set escape 0xff
- set device ui-gate:ppp-in/tcp
- set dial
- set timeout 30
- set log Phase Chat Connect hdlc LCP IPCP CCP tun
- set ifaddr 10.0.4.2 10.0.4.1
-.Ed
-.Pp
-with the route setup in
-.Pa /etc/ppp/ppp.linkup :
-.Bd -literal -offset indent
-ui-gate:
- add 10.0.2.0/24 HISADDR
-.Ed
-.Pp
-Again, if you're enabling PAP, you'll also need this in the
-.Pa /etc/ppp/ppp.conf
-profile:
-.Bd -literal -offset indent
- set authname MyAuthName
- set authkey MyAuthKey
-.Ed
-.Pp
-We're assigning the address of 10.0.4.1 to ui-gate, and the address
-10.0.4.2 to awfulhak.
-To open the connection, just type
-.Pp
-.Dl awfulhak # ppp -background ui-gate
-.Pp
-The result will be an additional "route" on awfulhak to the
-10.0.2.0/24 network via the TCP connection, and an additional
-"route" on ui-gate to the 10.0.1.0/24 network.
-The networks are effectively bridged - the underlying TCP
-connection may be across a public network (such as the
-Internet), and the
-.Em PPP
-traffic is conceptually encapsulated
-(although not packet by packet) inside the TCP stream between
-the two gateways.
-.Pp
-The major disadvantage of this mechanism is that there are two
-"guaranteed delivery" mechanisms in place - the underlying TCP
-stream and whatever protocol is used over the
-.Em PPP
-link - probably TCP again.
-If packets are lost, both levels will
-get in each others way trying to negotiate sending of the missing
-packet.
-.Pp
-To avoid this overhead, it is also possible to do all this using
-UDP instead of TCP as the transport by simply changing the protocol
-from "tcp" to "udp".
-When using UDP as a transport,
-.Nm
-will operate in synchronous mode.
-This is another gain as the incoming
-data does not have to be rearranged into packets.
-.Pp
-Care should be taken when adding a default route through a tunneled
-setup like this.
-It is quite common for the default route
-(added in
-.Pa /etc/ppp/ppp.linkup )
-to end up routing the link's TCP connection through the tunnel,
-effectively garrotting the connection.
-To avoid this, make sure you add a static route for the benefit of
-the link:
-.Bd -literal -offset indent
-ui-gate:
- set escape 0xff
- set device ui-gate:ppp-in/tcp
- add ui-gate x.x.x.x
- .....
-.Ed
-.Pp
-where
-.Dq x.x.x.x
-is the IP number that your route to
-.Dq ui-gate
-would normally use.
-.Pp
-When routing your connection accross a public network such as the Internet,
-it is preferable to encrypt the data.
-This can be done with the help of the MPPE protocol, although currently this
-means that you will not be able to also compress the traffic as MPPE is
-implemented as a compression layer (thank Microsoft for this).
-To enable MPPE encryption, add the following lines to
-.Pa /etc/ppp/ppp.conf
-on the server:
-.Bd -literal -offset indent
-  enable MSCHAPv2
-  disable deflate pred1
-  deny deflate pred1
-.Ed
-.Pp
-ensuring that you've put the requisite entry in
-.Pa /etc/ppp/ppp.secret
-(MSCHAPv2 is challenge based, so
-.Xr passwd 5
-cannot be used)
-.Pp
-MSCHAPv2 and MPPE are accepted by default, so the client end should work
-without any additional changes (although ensure you have
-.Dq set authname
-and
-.Dq set authkey
-in your profile).
-.Sh NETWORK ADDRESS TRANSLATION (PACKET ALIASING)
-The
-.Fl nat
-command line option enables network address translation (a.k.a. packet
-aliasing).
-This allows the
-.Nm
-host to act as a masquerading gateway for other computers over
-a local area network.
-Outgoing IP packets are NAT'd so that they appear to come from the
-.Nm
-host, and incoming packets are de-NAT'd so that they are routed
-to the correct machine on the local area network.
-NAT allows computers on private, unregistered subnets to have Internet
-access, although they are invisible from the outside world.
-In general, correct
-.Nm
-operation should first be verified with network address translation disabled.
-Then, the
-.Fl nat
-option should be switched on, and network applications (web browser,
-.Xr telnet 1 ,
-.Xr ftp 1 ,
-.Xr ping 8 ,
-.Xr traceroute 8 )
-should be checked on the
-.Nm
-host.
-Finally, the same or similar applications should be checked on other
-computers in the LAN.
-If network applications work correctly on the
-.Nm
-host, but not on other machines in the LAN, then the masquerading
-software is working properly, but the host is either not forwarding
-or possibly receiving IP packets.
-Check that IP forwarding is enabled in
-.Pa /etc/rc.conf
-and that other machines have designated the
-.Nm
-host as the gateway for the LAN.
-.Sh PACKET FILTERING
-This implementation supports packet filtering.
-There are four kinds of
-filters: the
-.Em in
-filter, the
-.Em out
-filter, the
-.Em dial
-filter and the
-.Em alive
-filter.
-Here are the basics:
-.Bl -bullet
-.It
-A filter definition has the following syntax:
-.Pp
-set filter
-.Ar name
-.Ar rule-no
-.Ar action
-.Op !\&
-.Oo
-.Op host
-.Ar src_addr Ns Op / Ns Ar width
-.Op Ar dst_addr Ns Op / Ns Ar width
-.Oc
-.Ar [ proto Op src Ar cmp port
-.Op dst Ar cmp port
-.Op estab
-.Op syn
-.Op finrst
-.Op timeout Ar secs ]
-.Bl -enum
-.It
-.Ar Name
-should be one of
-.Sq in ,
-.Sq out ,
-.Sq dial
-or
-.Sq alive .
-.It
-.Ar Rule-no
-is a numeric value between
-.Sq 0
-and
-.Sq 39
-specifying the rule number.
-Rules are specified in numeric order according to
-.Ar rule-no ,
-but only if rule
-.Sq 0
-is defined.
-.It
-.Ar Action
-may be specified as
-.Sq permit
-or
-.Sq deny ,
-in which case, if a given packet matches the rule, the associated action
-is taken immediately.
-.Ar Action
-can also be specified as
-.Sq clear
-to clear the action associated with that particular rule, or as a new
-rule number greater than the current rule.
-In this case, if a given
-packet matches the current rule, the packet will next be matched against
-the new rule number (rather than the next rule number).
-.Pp
-The
-.Ar action
-may optionally be followed with an exclamation mark
-.Pq Dq !\& ,
-telling
-.Nm
-to reverse the sense of the following match.
-.It
-.Op Ar src_addr Ns Op / Ns Ar width
-and
-.Op Ar dst_addr Ns Op / Ns Ar width
-are the source and destination IP number specifications.
-If
-.Op / Ns Ar width
-is specified, it gives the number of relevant netmask bits,
-allowing the specification of an address range.
-.Pp
-Either
-.Ar src_addr
-or
-.Ar dst_addr
-may be given the values
-.Dv MYADDR
-or
-.Dv HISADDR
-(refer to the description of the
-.Dq bg
-command for a description of these values).
-When these values are used,
-the filters will be updated any time the values change.
-This is similar to the behaviour of the
-.Dq add
-command below.
-.It
-.Ar Proto
-must be one of
-.Sq icmp ,
-.Sq igmp ,
-.Sq ipip ,
-.Sq ospf ,
-.Sq udp
-or
-.Sq tcp .
-.It
-.Ar Cmp
-is one of
-.Sq \&lt ,
-.Sq \&eq
-or
-.Sq \&gt ,
-meaning less-than, equal and greater-than respectively.
-.Ar Port
-can be specified as a numeric port or by service name from
-.Pa /etc/services .
-.It
-The
-.Sq estab ,
-.Sq syn ,
-and
-.Sq finrst
-flags are only allowed when
-.Ar proto
-is set to
-.Sq tcp ,
-and represent the TH_ACK, TH_SYN and TH_FIN or TH_RST TCP flags respectively.
-.It
-The timeout value adjusts the current idle timeout to at least
-.Ar secs
-seconds.
-If a timeout is given in the alive filter as well as in the in/out
-filter, the in/out value is used.
-If no timeout is given, the default timeout (set using
-.Ic set timeout
-and defaulting to 180 seconds) is used.
-.El
-.Pp
-.It
-Each filter can hold up to 40 rules, starting from rule 0.
-The entire rule set is not effective until rule 0 is defined,
-i.e., the default is to allow everything through.
-.It
-If no rule in a defined set of rules matches a packet, that packet will
-be discarded (blocked).
-If there are no rules in a given filter, the packet will be permitted.
-.It
-It's possible to filter based on the payload of UDP frames where those
-frames contain a
-.Em PROTO_IP
-.Em PPP
-frame header.
-See the
-.Ar filter-decapsulation
-option below for further details.
-.It
-Use
-.Dq set filter Ar name No -1
-to flush all rules.
-.El
-.Pp
-See
-.Pa /usr/share/examples/ppp/ppp.conf.sample .
-.Sh SETTING THE IDLE TIMER
-To check/set the idle timer, use the
-.Dq show bundle
-and
-.Dq set timeout
-commands:
-.Bd -literal -offset indent
-ppp ON awfulhak> set timeout 600
-.Ed
-.Pp
-The timeout period is measured in seconds, the default value for which
-is 180 seconds
-(or 3 min).
-To disable the idle timer function, use the command
-.Bd -literal -offset indent
-ppp ON awfulhak> set timeout 0
-.Ed
-.Pp
-In
-.Fl ddial
-and
-.Fl dedicated
-modes, the idle timeout is ignored.
-In
-.Fl auto
-mode, when the idle timeout causes the
-.Em PPP
-session to be
-closed, the
-.Nm
-program itself remains running.
-Another trigger packet will cause it to attempt to re-establish the link.
-.Sh PREDICTOR-1 and DEFLATE COMPRESSION
-.Nm
-supports both Predictor type 1 and deflate compression.
-By default,
-.Nm
-will attempt to use (or be willing to accept) both compression protocols
-when the peer agrees
-(or requests them).
-The deflate protocol is preferred by
-.Nm .
-Refer to the
-.Dq disable
-and
-.Dq deny
-commands if you wish to disable this functionality.
-.Pp
-It is possible to use a different compression algorithm in each direction
-by using only one of
-.Dq disable deflate
-and
-.Dq deny deflate
-(assuming that the peer supports both algorithms).
-.Pp
-By default, when negotiating DEFLATE,
-.Nm
-will use a window size of 15.
-Refer to the
-.Dq set deflate
-command if you wish to change this behaviour.
-.Pp
-A special algorithm called DEFLATE24 is also available, and is disabled
-and denied by default.
-This is exactly the same as DEFLATE except that
-it uses CCP ID 24 to negotiate.
-This allows
-.Nm
-to successfully negotiate DEFLATE with
-.Nm pppd
-version 2.3.*.
-.Sh CONTROLLING IP ADDRESS
-.Nm
-uses IPCP to negotiate IP addresses.
-Each side of the connection
-specifies the IP address that it's willing to use, and if the requested
-IP address is acceptable then
-.Nm
-returns ACK to the requester.
-Otherwise,
-.Nm
-returns NAK to suggest that the peer use a different IP address.
-When
-both sides of the connection agree to accept the received request (and
-send ACK), IPCP is set to the open state and a network level connection
-is established.
-To control this IPCP behaviour, this implementation has the
-.Dq set ifaddr
-command for defining the local and remote IP address:
-.Bd -ragged -offset indent
-.No set ifaddr Oo Ar src_addr Ns
-.Op / Ns Ar \&nn
-.Oo Ar dst_addr Ns Op / Ns Ar \&nn
-.Oo Ar netmask
-.Op Ar trigger_addr
-.Oc
-.Oc
-.Oc
-.Ed
-.Pp
-where,
-.Sq src_addr
-is the IP address that the local side is willing to use,
-.Sq dst_addr
-is the IP address which the remote side should use and
-.Sq netmask
-is the netmask that should be used.
-.Sq Src_addr
-defaults to the current
-.Xr hostname 1 ,
-.Sq dst_addr
-defaults to 0.0.0.0, and
-.Sq netmask
-defaults to whatever mask is appropriate for
-.Sq src_addr .
-It is only possible to make
-.Sq netmask
-smaller than the default.
-The usual value is 255.255.255.255, as
-most kernels ignore the netmask of a POINTOPOINT interface.
-.Pp
-Some incorrect
-.Em PPP
-implementations require that the peer negotiates a specific IP
-address instead of
-.Sq src_addr .
-If this is the case,
-.Sq trigger_addr
-may be used to specify this IP number.
-This will not affect the
-routing table unless the other side agrees with this proposed number.
-.Bd -literal -offset indent
-set ifaddr 192.244.177.38 192.244.177.2 255.255.255.255 0.0.0.0
-.Ed
-.Pp
-The above specification means:
-.Pp
-.Bl -bullet -compact
-.It
-I will first suggest that my IP address should be 0.0.0.0, but I
-will only accept an address of 192.244.177.38.
-.It
-I strongly insist that the peer uses 192.244.177.2 as his own
-address and won't permit the use of any IP address but 192.244.177.2.
-When the peer requests another IP address, I will always suggest that
-it uses 192.244.177.2.
-.It
-The routing table entry will have a netmask of 0xffffffff.
-.El
-.Pp
-This is all fine when each side has a pre-determined IP address, however
-it is often the case that one side is acting as a server which controls
-all IP addresses and the other side should go along with it.
-In order to allow more flexible behaviour, the
-.Dq set ifaddr
-command allows the user to specify IP addresses more loosely:
-.Pp
-.Dl set ifaddr 192.244.177.38/24 192.244.177.2/20
-.Pp
-A number followed by a slash
-.Pq Dq /
-represents the number of bits significant in the IP address.
-The above example means:
-.Pp
-.Bl -bullet -compact
-.It
-I'd like to use 192.244.177.38 as my address if it is possible, but I'll
-also accept any IP address between 192.244.177.0 and 192.244.177.255.
-.It
-I'd like to make him use 192.244.177.2 as his own address, but I'll also
-permit him to use any IP address between 192.244.176.0 and
-192.244.191.255.
-.It
-As you may have already noticed, 192.244.177.2 is equivalent to saying
-192.244.177.2/32.
-.It
-As an exception, 0 is equivalent to 0.0.0.0/0, meaning that I have no
-preferred IP address and will obey the remote peers selection.
-When using zero, no routing table entries will be made until a connection
-is established.
-.It
-192.244.177.2/0 means that I'll accept/permit any IP address but I'll
-try to insist that 192.244.177.2 be used first.
-.El
-.Sh CONNECTING WITH YOUR INTERNET SERVICE PROVIDER
-The following steps should be taken when connecting to your ISP:
-.Bl -enum
-.It
-Describe your providers phone number(s) in the dial script using the
-.Dq set phone
-command.
-This command allows you to set multiple phone numbers for
-dialing and redialing separated by either a pipe
-.Pq Dq \&|
-or a colon
-.Pq Dq \&: :
-.Bd -ragged -offset indent
-.No set phone Ar telno Ns Xo
-.Oo \&| Ns Ar backupnumber
-.Oc Ns ... Ns Oo : Ns Ar nextnumber
-.Oc Ns ...
-.Xc
-.Ed
-.Pp
-Numbers after the first in a pipe-separated list are only used if the
-previous number was used in a failed dial or login script.
-Numbers
-separated by a colon are used sequentially, irrespective of what happened
-as a result of using the previous number.
-For example:
-.Bd -literal -offset indent
-set phone "1234567|2345678:3456789|4567890"
-.Ed
-.Pp
-Here, the 1234567 number is attempted.
-If the dial or login script fails,
-the 2345678 number is used next time, but *only* if the dial or login script
-fails.
-On the dial after this, the 3456789 number is used.
-The 4567890
-number is only used if the dial or login script using the 3456789 fails.
-If the login script of the 2345678 number fails, the next number is still the
-3456789 number.
-As many pipes and colons can be used as are necessary
-(although a given site would usually prefer to use either the pipe or the
-colon, but not both).
-The next number redial timeout is used between all numbers.
-When the end of the list is reached, the normal redial period is
-used before starting at the beginning again.
-The selected phone number is substituted for the \\\\T string in the
-.Dq set dial
-command (see below).
-.It
-Set up your redial requirements using
-.Dq set redial .
-For example, if you have a bad telephone line or your provider is
-usually engaged (not so common these days), you may want to specify
-the following:
-.Bd -literal -offset indent
-set redial 10 4
-.Ed
-.Pp
-This says that up to 4 phone calls should be attempted with a pause of 10
-seconds before dialing the first number again.
-.It
-Describe your login procedure using the
-.Dq set dial
-and
-.Dq set login
-commands.
-The
-.Dq set dial
-command is used to talk to your modem and establish a link with your
-ISP, for example:
-.Bd -literal -offset indent
-set dial "ABORT BUSY ABORT NO\\\\sCARRIER TIMEOUT 4 \\"\\" \e
-  ATZ OK-ATZ-OK ATDT\\\\T TIMEOUT 60 CONNECT"
-.Ed
-.Pp
-This modem "chat" string means:
-.Bl -bullet
-.It
-Abort if the string "BUSY" or "NO CARRIER" are received.
-.It
-Set the timeout to 4 seconds.
-.It
-Expect nothing.
-.It
-Send ATZ.
-.It
-Expect OK.
-If that's not received within the 4 second timeout, send ATZ
-and expect OK.
-.It
-Send ATDTxxxxxxx where xxxxxxx is the next number in the phone list from
-above.
-.It
-Set the timeout to 60.
-.It
-Wait for the CONNECT string.
-.El
-.Pp
-Once the connection is established, the login script is executed.
-This script is written in the same style as the dial script, but care should
-be taken to avoid having your password logged:
-.Bd -literal -offset indent
-set authkey MySecret
-set login "TIMEOUT 15 login:-\\\\r-login: awfulhak \e
-  word: \\\\P ocol: PPP HELLO"
-.Ed
-.Pp
-This login "chat" string means:
-.Bl -bullet
-.It
-Set the timeout to 15 seconds.
-.It
-Expect "login:".
-If it's not received, send a carriage return and expect
-"login:" again.
-.It
-Send "awfulhak"
-.It
-Expect "word:" (the tail end of a "Password:" prompt).
-.It
-Send whatever our current
-.Ar authkey
-value is set to.
-.It
-Expect "ocol:" (the tail end of a "Protocol:" prompt).
-.It
-Send "PPP".
-.It
-Expect "HELLO".
-.El
-.Pp
-The
-.Dq set authkey
-command is logged specially.
-When
-.Ar command
-or
-.Ar chat
-logging is enabled, the actual password is not logged;
-.Sq ********
-is logged instead.
-.Pp
-Login scripts vary greatly between ISPs.
-If you're setting one up for the first time,
-.Em ENABLE CHAT LOGGING
-so that you can see if your script is behaving as you expect.
-.It
-Use
-.Dq set device
-and
-.Dq set speed
-to specify your serial line and speed, for example:
-.Bd -literal -offset indent
-set device /dev/cuaa0
-set speed 115200
-.Ed
-.Pp
-Cuaa0 is the first serial port on
-.Fx .
-If you're running
-.Nm
-on
-.Ox ,
-cua00 is the first.
-A speed of 115200 should be specified
-if you have a modem capable of bit rates of 28800 or more.
-In general, the serial speed should be about four times the modem speed.
-.It
-Use the
-.Dq set ifaddr
-command to define the IP address.
-.Bl -bullet
-.It
-If you know what IP address your provider uses, then use it as the remote
-address (dst_addr), otherwise choose something like 10.0.0.2/0 (see below).
-.It
-If your provider has assigned a particular IP address to you, then use
-it as your address (src_addr).
-.It
-If your provider assigns your address dynamically, choose a suitably
-unobtrusive and unspecific IP number as your address.
-10.0.0.1/0 would be appropriate.
-The bit after the / specifies how many bits of the
-address you consider to be important, so if you wanted to insist on
-something in the class C network 1.2.3.0, you could specify 1.2.3.1/24.
-.It
-If you find that your ISP accepts the first IP number that you suggest,
-specify third and forth arguments of
-.Dq 0.0.0.0 .
-This will force your ISP to assign a number.
-(The third argument will
-be ignored as it is less restrictive than the default mask for your
-.Sq src_addr .
-.El
-.Pp
-An example for a connection where you don't know your IP number or your
-ISPs IP number would be:
-.Bd -literal -offset indent
-set ifaddr 10.0.0.1/0 10.0.0.2/0 0.0.0.0 0.0.0.0
-.Ed
-.Pp
-.It
-In most cases, your ISP will also be your default router.
-If this is the case, add the line
-.Bd -literal -offset indent
-add default HISADDR
-.Ed
-.Pp
-to
-.Pa /etc/ppp/ppp.conf .
-.Pp
-This tells
-.Nm
-to add a default route to whatever the peer address is
-(10.0.0.2 in this example).
-This route is
-.Sq sticky ,
-meaning that should the value of
-.Dv HISADDR
-change, the route will be updated accordingly.
-.Pp
-Previous versions of
-.Nm
-required a similar entry in the
-.Pa /etc/ppp/ppp.linkup
-file.
-Since the advent of
-.Sq sticky routes ,
-this is no longer required.
-.It
-If your provider requests that you use PAP/CHAP authentication methods, add
-the next lines to your
-.Pa /etc/ppp/ppp.conf
-file:
-.Bd -literal -offset indent
-set authname MyName
-set authkey MyPassword
-.Ed
-.Pp
-Both are accepted by default, so
-.Nm
-will provide whatever your ISP requires.
-.Pp
-It should be noted that a login script is rarely (if ever) required
-when PAP or CHAP are in use.
-.It
-Ask your ISP to authenticate your nameserver address(es) with the line
-.Bd -literal -offset indent
-enable dns
-.Ed
-.Pp
-Do
-.Em NOT
-do this if you are running a local DNS unless you also either use
-.Dq resolv readonly
-or have
-.Dq resolv restore
-in
-.Pa /etc/ppp/ppp.linkdown ,
-as
-.Nm
-will simply circumvent its use by entering some nameserver lines in
-.Pa /etc/resolv.conf .
-.El
-.Pp
-Please refer to
-.Pa /usr/share/examples/ppp/ppp.conf.sample
-and
-.Pa /usr/share/examples/ppp/ppp.linkup.sample
-for some real examples.
-The pmdemand label should be appropriate for most ISPs.
-.Sh LOGGING FACILITY
-.Nm
-is able to generate the following log info either via
-.Xr syslog 3
-or directly to the screen:
-.Pp
-.Bl -tag -width XXXXXXXXX -offset XXX -compact
-.It Li All
-Enable all logging facilities.
-This generates a lot of log.
-The most common use of 'all' is as a basis, where you remove some facilities
-after enabling 'all' ('debug' and 'timer' are usually best disabled.)
-.It Li Async
-Dump async level packet in hex.
-.It Li CBCP
-Generate CBCP (CallBack Control Protocol) logs.
-.It Li CCP
-Generate a CCP packet trace.
-.It Li Chat
-Generate
-.Sq dial ,
-.Sq login ,
-.Sq logout
-and
-.Sq hangup
-chat script trace logs.
-.It Li Command
-Log commands executed either from the command line or any of the configuration
-files.
-.It Li Connect
-Log Chat lines containing the string "CONNECT".
-.It Li Debug
-Log debug information.
-.It Li DNS
-Log DNS QUERY packets.
-.It Li Filter
-Log packets permitted by the dial filter and denied by any filter.
-.It Li HDLC
-Dump HDLC packet in hex.
-.It Li ID0
-Log all function calls specifically made as user id 0.
-.It Li IPCP
-Generate an IPCP packet trace.
-.It Li LCP
-Generate an LCP packet trace.
-.It Li LQM
-Generate LQR reports.
-.It Li Phase
-Phase transition log output.
-.It Li Physical
-Dump physical level packet in hex.
-.It Li Sync
-Dump sync level packet in hex.
-.It Li TCP/IP
-Dump all TCP/IP packets.
-.It Li Timer
-Log timer manipulation.
-.It Li TUN
-Include the tun device on each log line.
-.It Li Warning
-Output to the terminal device.
-If there is currently no terminal,
-output is sent to the log file using syslogs
-.Dv LOG_WARNING .
-.It Li Error
-Output to both the terminal device
-and the log file using syslogs
-.Dv LOG_ERROR .
-.It Li Alert
-Output to the log file using
-.Dv LOG_ALERT .
-.El
-.Pp
-The
-.Dq set log
-command allows you to set the logging output level.
-Multiple levels can be specified on a single command line.
-The default is equivalent to
-.Dq set log Phase .
-.Pp
-It is also possible to log directly to the screen.
-The syntax is the same except that the word
-.Dq local
-should immediately follow
-.Dq set log .
-The default is
-.Dq set log local
-(i.e., only the un-maskable warning, error and alert output).
-.Pp
-If The first argument to
-.Dq set log Op local
-begins with a
-.Sq +
-or a
-.Sq -
-character, the current log levels are
-not cleared, for example:
-.Bd -literal -offset indent
-PPP ON awfulhak> set log phase
-PPP ON awfulhak> show log
-Log:   Phase Warning Error Alert
-Local: Warning Error Alert
-PPP ON awfulhak> set log +tcp/ip -warning
-PPP ON awfulhak> set log local +command
-PPP ON awfulhak> show log
-Log:   Phase TCP/IP Warning Error Alert
-Local: Command Warning Error Alert
-.Ed
-.Pp
-Log messages of level Warning, Error and Alert are not controllable
-using
-.Dq set log Op local .
-.Pp
-The
-.Ar Warning
-level is special in that it will not be logged if it can be displayed
-locally.
-.Sh SIGNAL HANDLING
-.Nm
-deals with the following signals:
-.Bl -tag -width "USR2"
-.It INT
-Receipt of this signal causes the termination of the current connection
-(if any).
-This will cause
-.Nm
-to exit unless it is in
-.Fl auto
-or
-.Fl ddial
-mode.
-.It HUP, TERM & QUIT
-These signals tell
-.Nm
-to exit.
-.It USR1
-This signal, tells
-.Nm
-to re-open any existing server socket, dropping all existing diagnostic
-connections.
-Sockets that couldn't previously be opened will be retried.
-.It USR2
-This signal, tells
-.Nm
-to close any existing server socket, dropping all existing diagnostic
-connections.
-.Dv SIGUSR1
-can still be used to re-open the socket.
-.El
-.Sh MULTI-LINK PPP
-If you wish to use more than one physical link to connect to a
-.Em PPP
-peer, that peer must also understand the
-.Em MULTI-LINK PPP
-protocol.
-Refer to RFC 1990 for specification details.
-.Pp
-The peer is identified using a combination of his
-.Dq endpoint discriminator
-and his
-.Dq authentication id .
-Either or both of these may be specified.
-It is recommended that
-at least one is specified, otherwise there is no way of ensuring that
-all links are actually connected to the same peer program, and some
-confusing lock-ups may result.
-Locally, these identification variables are specified using the
-.Dq set enddisc
-and
-.Dq set authname
-commands.
-The
-.Sq authname
-(and
-.Sq authkey )
-must be agreed in advance with the peer.
-.Pp
-Multi-link capabilities are enabled using the
-.Dq set mrru
-command (set maximum reconstructed receive unit).
-Once multi-link is enabled,
-.Nm
-will attempt to negotiate a multi-link connection with the peer.
-.Pp
-By default, only one
-.Sq link
-is available
-(called
-.Sq deflink ) .
-To create more links, the
-.Dq clone
-command is used.
-This command will clone existing links, where all
-characteristics are the same except:
-.Bl -enum
-.It
-The new link has its own name as specified on the
-.Dq clone
-command line.
-.It
-The new link is an
-.Sq interactive
-link.
-Its mode may subsequently be changed using the
-.Dq set mode
-command.
-.It
-The new link is in a
-.Sq closed
-state.
-.El
-.Pp
-A summary of all available links can be seen using the
-.Dq show links
-command.
-.Pp
-Once a new link has been created, command usage varies.
-All link specific commands must be prefixed with the
-.Dq link Ar name
-command, specifying on which link the command is to be applied.
-When only a single link is available,
-.Nm
-is smart enough not to require the
-.Dq link Ar name
-prefix.
-.Pp
-Some commands can still be used without specifying a link - resulting
-in an operation at the
-.Sq bundle
-level.
-For example, once two or more links are available, the command
-.Dq show ccp
-will show CCP configuration and statistics at the multi-link level, and
-.Dq link deflink show ccp
-will show the same information at the
-.Dq deflink
-link level.
-.Pp
-Armed with this information, the following configuration might be used:
-.Pp
-.Bd -literal -offset indent
-mp:
- set timeout 0
- set log phase chat
- set device /dev/cuaa0 /dev/cuaa1 /dev/cuaa2
- set phone "123456789"
- set dial "ABORT BUSY ABORT NO\\sCARRIER TIMEOUT 5 \\"\\" ATZ \e
-           OK-AT-OK \\\\dATDT\\\\T TIMEOUT 45 CONNECT"
- set login
- set ifaddr 10.0.0.1/0 10.0.0.2/0 0.0.0.0 0.0.0.0
- set authname ppp
- set authkey ppppassword
-
- set mrru 1500
- clone 1,2,3		# Create 3 new links - duplicates of the default
- link deflink remove	# Delete the default link (called ``deflink'')
-.Ed
-.Pp
-Note how all cloning is done at the end of the configuration.
-Usually, the link will be configured first, then cloned.
-If you wish all links
-to be up all the time, you can add the following line to the end of your
-configuration.
-.Pp
-.Bd -literal -offset indent
-  link 1,2,3 set mode ddial
-.Ed
-.Pp
-If you want the links to dial on demand, this command could be used:
-.Pp
-.Bd -literal -offset indent
-  link * set mode auto
-.Ed
-.Pp
-Links may be tied to specific names by removing the
-.Dq set device
-line above, and specifying the following after the
-.Dq clone
-command:
-.Pp
-.Bd -literal -offset indent
- link 1 set device /dev/cuaa0
- link 2 set device /dev/cuaa1
- link 3 set device /dev/cuaa2
-.Ed
-.Pp
-Use the
-.Dq help
-command to see which commands require context (using the
-.Dq link
-command), which have optional
-context and which should not have any context.
-.Pp
-When
-.Nm
-has negotiated
-.Em MULTI-LINK
-mode with the peer, it creates a local domain socket in the
-.Pa /var/run
-directory.
-This socket is used to pass link information (including
-the actual link file descriptor) between different
-.Nm
-invocations.
-This facilitates
-.Nm Ns No 's
-ability to be run from a
-.Xr getty 8
-or directly from
-.Pa /etc/gettydefs
-(using the
-.Sq pp=
-capability), without needing to have initial control of the serial
-line.
-Once
-.Nm
-negotiates multi-link mode, it will pass its open link to any
-already running process.
-If there is no already running process,
-.Nm
-will act as the master, creating the socket and listening for new
-connections.
-.Sh PPP COMMAND LIST
-This section lists the available commands and their effect.
-They are usable either from an interactive
-.Nm
-session, from a configuration file or from a
-.Xr pppctl 8
-or
-.Xr telnet 1
-session.
-.Bl -tag -width 2n
-.It accept|deny|enable|disable Ar option....
-These directives tell
-.Nm
-how to negotiate the initial connection with the peer.
-Each
-.Dq option
-has a default of either accept or deny and enable or disable.
-.Dq Accept
-means that the option will be ACK'd if the peer asks for it.
-.Dq Deny
-means that the option will be NAK'd if the peer asks for it.
-.Dq Enable
-means that the option will be requested by us.
-.Dq Disable
-means that the option will not be requested by us.
-.Pp
-.Dq Option
-may be one of the following:
-.Bl -tag -width 2n
-.It acfcomp
-Default: Enabled and Accepted.
-ACFComp stands for Address and Control Field Compression.
-Non LCP packets will usually have an address
-field of 0xff (the All-Stations address) and a control field of
-0x03 (the Unnumbered Information command).
-If this option is
-negotiated, these two bytes are simply not sent, thus minimising
-traffic.
-.Pp
-See
-.Pa rfc1662
-for details.
-.It chap Ns Op \&05
-Default: Disabled and Accepted.
-CHAP stands for Challenge Handshake Authentication Protocol.
-Only one of CHAP and PAP (below) may be negotiated.
-With CHAP, the authenticator sends a "challenge" message to its peer.
-The peer uses a one-way hash function to encrypt the
-challenge and sends the result back.
-The authenticator does the same, and compares the results.
-The advantage of this mechanism is that no
-passwords are sent across the connection.
-A challenge is made when the connection is first made.
-Subsequent challenges may occur.
-If you want to have your peer authenticate itself, you must
-.Dq enable chap .
-in
-.Pa /etc/ppp/ppp.conf ,
-and have an entry in
-.Pa /etc/ppp/ppp.secret
-for the peer.
-.Pp
-When using CHAP as the client, you need only specify
-.Dq AuthName
-and
-.Dq AuthKey
-in
-.Pa /etc/ppp/ppp.conf .
-CHAP is accepted by default.
-Some
-.Em PPP
-implementations use "MS-CHAP" rather than MD5 when encrypting the
-challenge.
-MS-CHAP is a combination of MD4 and DES.
-If
-.Nm
-was built on a machine with DES libraries available, it will respond
-to MS-CHAP authentication requests, but will never request them.
-.It deflate
-Default: Enabled and Accepted.
-This option decides if deflate
-compression will be used by the Compression Control Protocol (CCP).
-This is the same algorithm as used by the
-.Xr gzip 1
-program.
-Note: There is a problem negotiating
-.Ar deflate
-capabilities with
-.Xr pppd 8
-- a
-.Em PPP
-implementation available under many operating systems.
-.Nm pppd
-(version 2.3.1) incorrectly attempts to negotiate
-.Ar deflate
-compression using type
-.Em 24
-as the CCP configuration type rather than type
-.Em 26
-as specified in
-.Pa rfc1979 .
-Type
-.Ar 24
-is actually specified as
-.Dq PPP Magna-link Variable Resource Compression
-in
-.Pa rfc1975 Ns !
-.Nm
-is capable of negotiating with
-.Nm pppd ,
-but only if
-.Dq deflate24
-is
-.Ar enable Ns No d
-and
-.Ar accept Ns No ed .
-.It deflate24
-Default: Disabled and Denied.
-This is a variance of the
-.Ar deflate
-option, allowing negotiation with the
-.Xr pppd 8
-program.
-Refer to the
-.Ar deflate
-section above for details.
-It is disabled by default as it violates
-.Pa rfc1975 .
-.It dns
-Default: Disabled and Denied.
-This option allows DNS negotiation.
-.Pp
-If
-.Dq enable Ns No d,
-.Nm
-will request that the peer confirms the entries in
-.Pa /etc/resolv.conf .
-If the peer NAKs our request (suggesting new IP numbers),
-.Pa /etc/resolv.conf
-is updated and another request is sent to confirm the new entries.
-.Pp
-If
-.Dq accept Ns No ed,
-.Nm
-will answer any DNS queries requested by the peer rather than rejecting
-them.
-The answer is taken from
-.Pa /etc/resolv.conf
-unless the
-.Dq set dns
-command is used as an override.
-.It enddisc
-Default: Enabled and Accepted.
-This option allows control over whether we
-negotiate an endpoint discriminator.
-We only send our discriminator if
-.Dq set enddisc
-is used and
-.Ar enddisc
-is enabled.
-We reject the peers discriminator if
-.Ar enddisc
-is denied.
-.It LANMan|chap80lm
-Default: Disabled and Accepted.
-The use of this authentication protocol
-is discouraged as it partially violates the authentication protocol by
-implementing two different mechanisms (LANMan & NT) under the guise of
-a single CHAP type (0x80).
-.Dq LANMan
-uses a simple DES encryption mechanism and is the least secure of the
-CHAP alternatives (although is still more secure than PAP).
-.Pp
-Refer to the
-.Dq MSChap
-description below for more details.
-.It lqr
-Default: Disabled and Accepted.
-This option decides if Link Quality Requests will be sent or accepted.
-LQR is a protocol that allows
-.Nm
-to determine that the link is down without relying on the modems
-carrier detect.
-When LQR is enabled,
-.Nm
-sends the
-.Em QUALPROTO
-option (see
-.Dq set lqrperiod
-below) as part of the LCP request.
-If the peer agrees, both sides will
-exchange LQR packets at the agreed frequency, allowing detailed link
-quality monitoring by enabling LQM logging.
-If the peer doesn't agree,
-.Nm
-will send ECHO LQR requests instead.
-These packets pass no information of interest, but they
-.Em MUST
-be replied to by the peer.
-.Pp
-Whether using LQR or ECHO LQR,
-.Nm
-will abruptly drop the connection if 5 unacknowledged packets have been
-sent rather than sending a 6th.
-A message is logged at the
-.Em PHASE
-level, and any appropriate
-.Dq reconnect
-values are honoured as if the peer were responsible for dropping the
-connection.
-.It mppe
-Default: Enabled and Accepted.
-This is Microsoft Point to Point Encryption scheme.
-MPPE key size can be
-40-, 56- and 128-bits.
-Refer to
-.Dq set mppe
-command.
-.It MSChapV2|chap81
-Default: Disabled and Accepted.
-It is very similar to standard CHAP (type 0x05)
-except that it issues challenges of a fixed 16 bytes in length and uses a
-combination of MD4, SHA-1 and DES to encrypt the challenge rather than using the
-standard MD5 mechanism.
-.It MSChap|chap80nt
-Default: Disabled and Accepted.
-The use of this authentication protocol
-is discouraged as it partially violates the authentication protocol by
-implementing two different mechanisms (LANMan & NT) under the guise of
-a single CHAP type (0x80).
-It is very similar to standard CHAP (type 0x05)
-except that it issues challenges of a fixed 8 bytes in length and uses a
-combination of MD4 and DES to encrypt the challenge rather than using the
-standard MD5 mechanism.
-CHAP type 0x80 for LANMan is also supported - see
-.Dq enable LANMan
-for details.
-.Pp
-Because both
-.Dq LANMan
-and
-.Dq NT
-use CHAP type 0x80, when acting as authenticator with both
-.Dq enable Ns No d ,
-.Nm
-will rechallenge the peer up to three times if it responds using the wrong
-one of the two protocols.
-This gives the peer a chance to attempt using both protocols.
-.Pp
-Conversely, when
-.Nm
-acts as the authenticatee with both protocols
-.Dq accept Ns No ed ,
-the protocols are used alternately in response to challenges.
-.Pp
-Note: If only LANMan is enabled,
-.Xr pppd 8
-(version 2.3.5) misbehaves when acting as authenticatee.
-It provides both
-the NT and the LANMan answers, but also suggests that only the NT answer
-should be used.
-.It pap
-Default: Disabled and Accepted.
-PAP stands for Password Authentication Protocol.
-Only one of PAP and CHAP (above) may be negotiated.
-With PAP, the ID and Password are sent repeatedly to the peer until
-authentication is acknowledged or the connection is terminated.
-This is a rather poor security mechanism.
-It is only performed when the connection is first established.
-If you want to have your peer authenticate itself, you must
-.Dq enable pap .
-in
-.Pa /etc/ppp/ppp.conf ,
-and have an entry in
-.Pa /etc/ppp/ppp.secret
-for the peer (although see the
-.Dq passwdauth
-and
-.Dq set radius
-options below).
-.Pp
-When using PAP as the client, you need only specify
-.Dq AuthName
-and
-.Dq AuthKey
-in
-.Pa /etc/ppp/ppp.conf .
-PAP is accepted by default.
-.It pred1
-Default: Enabled and Accepted.
-This option decides if Predictor 1
-compression will be used by the Compression Control Protocol (CCP).
-.It protocomp
-Default: Enabled and Accepted.
-This option is used to negotiate
-PFC (Protocol Field Compression), a mechanism where the protocol
-field number is reduced to one octet rather than two.
-.It shortseq
-Default: Enabled and Accepted.
-This option determines if
-.Nm
-will request and accept requests for short
-(12 bit)
-sequence numbers when negotiating multi-link mode.
-This is only applicable if our MRRU is set (thus enabling multi-link).
-.It vjcomp
-Default: Enabled and Accepted.
-This option determines if Van Jacobson header compression will be used.
-.El
-.Pp
-The following options are not actually negotiated with the peer.
-Therefore, accepting or denying them makes no sense.
-.Bl -tag -width 2n
-.It filter-decapsulation
-Default: Disabled.
-When this option is enabled,
-.Nm
-will examine UDP frames to see if they actually contain a
-.Em PPP
-frame as their payload.
-If this is the case, all filters will operate on the payload rather
-than the actual packet.
-.Pp
-This is useful if you want to send PPPoUDP traffic over a
-.Em PPP
-link, but want that link to do smart things with the real data rather than
-the UDP wrapper.
-.Pp
-The UDP frame payload must not be compressed in any way, otherwise
-.Nm
-will not be able to interpret it.
-It's therefore recommended that you
-.Ic disable vj pred1 deflate
-and
-.Ic deny vj pred1 deflate
-in the configuration for the
-.Nm
-invocation with the udp link.
-.It idcheck
-Default: Enabled.
-When
-.Nm
-exchanges low-level LCP, CCP and IPCP configuration traffic, the
-.Em Identifier
-field of any replies is expected to be the same as that of the request.
-By default,
-.Nm
-drops any reply packets that do not contain the expected identifier
-field, reporting the fact at the respective log level.
-If
-.Ar idcheck
-is disabled,
-.Nm
-will ignore the identifier field.
-.It keep-session
-Default: Disabled.
-When
-.Nm
-runs as a Multi-link server, a different
-.Nm
-instance initially receives each connection.
-After determining that
-the link belongs to an already existing bundle (controlled by another
-.Nm
-invocation),
-.Nm
-will transfer the link to that process.
-.Pp
-If the link is a tty device or if this option is enabled,
-.Nm
-will not exit, but will change its process name to
-.Dq session owner
-and wait for the controlling
-.Nm
-to finish with the link and deliver a signal back to the idle process.
-This prevents the confusion that results from
-.Nm Ns No 's
-parent considering the link resource available again.
-.Pp
-For tty devices that have entries in
-.Pa /etc/ttys ,
-this is necessary to prevent another
-.Xr getty 8
-from being started, and for program links such as
-.Xr sshd 8 ,
-it prevents
-.Xr sshd 8
-from exiting due to the death of its child.
-As
-.Nm
-cannot determine its parents requirements (except for the tty case), this
-option must be enabled manually depending on the circumstances.
-.It loopback
-Default: Enabled.
-When
-.Ar loopback
-is enabled,
-.Nm
-will automatically loop back packets being sent
-out with a destination address equal to that of the
-.Em PPP
-interface.
-If disabled,
-.Nm
-will send the packet, probably resulting in an ICMP redirect from
-the other end.
-It is convenient to have this option enabled when
-the interface is also the default route as it avoids the necessity
-of a loopback route.
-.It passwdauth
-Default: Disabled.
-Enabling this option will tell the PAP authentication
-code to use the password database (see
-.Xr passwd 5 )
-to authenticate the caller if they cannot be found in the
-.Pa /etc/ppp/ppp.secret
-file.
-.Pa /etc/ppp/ppp.secret
-is always checked first.
-If you wish to use passwords from
-.Xr passwd 5 ,
-but also to specify an IP number or label for a given client, use
-.Dq \&*
-as the client password in
-.Pa /etc/ppp/ppp.secret .
-.It proxy
-Default: Disabled.
-Enabling this option will tell
-.Nm
-to proxy ARP for the peer.
-This means that
-.Nm
-will make an entry in the ARP table using
-.Dv HISADDR
-and the
-.Dv MAC
-address of the local network in which
-.Dv HISADDR
-appears.
-This allows other machines connecteed to the LAN to talk to
-the peer as if the peer itself was connected to the LAN.
-The proxy entry cannot be made unless
-.Dv HISADDR
-is an address from a LAN.
-.It proxyall
-Default: Disabled.
-Enabling this will tell
-.Nm
-to add proxy arp entries for every IP address in all class C or
-smaller subnets routed via the tun interface.
-.Pp
-Proxy arp entries are only made for sticky routes that are added
-using the
-.Dq add
-command.
-No proxy arp entries are made for the interface address itself
-(as created by the
-.Dq set ifaddr
-command).
-.It sroutes
-Default: Enabled.
-When the
-.Dq add
-command is used with the
-.Dv HISADDR
-or
-.Dv MYADDR
-values, entries are stored in the
-.Sq stick route
-list.
-Each time
-.Dv HISADDR
-or
-.Dv MYADDR
-change, this list is re-applied to the routing table.
-.Pp
-Disabling this option will prevent the re-application of sticky routes,
-although the
-.Sq stick route
-list will still be maintained.
-.It Op tcp Ns Xo
-.No mssfixup
-.Xc
-Default: Enabled.
-This option tells
-.Nm
-to adjust TCP SYN packets so that the maximum receive segment
-size is not greater than the amount allowed by the interface MTU.
-.It throughput
-Default: Enabled.
-This option tells
-.Nm
-to gather throughput statistics.
-Input and output is sampled over
-a rolling 5 second window, and current, best and total figures are retained.
-This data is output when the relevant
-.Em PPP
-layer shuts down, and is also available using the
-.Dq show
-command.
-Throughput statistics are available at the
-.Dq IPCP
-and
-.Dq physical
-levels.
-.It utmp
-Default: Enabled.
-Normally, when a user is authenticated using PAP or CHAP, and when
-.Nm
-is running in
-.Fl direct
-mode, an entry is made in the utmp and wtmp files for that user.
-Disabling this option will tell
-.Nm
-not to make any utmp or wtmp entries.
-This is usually only necessary if
-you require the user to both login and authenticate themselves.
-.It iface-alias
-Default: Enabled if
-.Fl nat
-is specified.
-This option simply tells
-.Nm
-to add new interface addresses to the interface rather than replacing them.
-The option can only be enabled if network address translation is enabled
-.Pq Dq nat enable yes .
-.Pp
-With this option enabled,
-.Nm
-will pass traffic for old interface addresses through the NAT engine
-(see
-.Xr libalias 3 ) ,
-resulting in the ability (in
-.Fl auto
-mode) to properly connect the process that caused the PPP link to
-come up in the first place.
-.Pp
-Disabling NAT with
-.Dq nat enable no
-will also disable
-.Sq iface-alias .
-.El
-.Pp
-.It add Ns Xo
-.Op !\&
-.Ar dest Ns Op / Ns Ar nn
-.Op Ar mask
-.Op Ar gateway
-.Xc
-.Ar Dest
-is the destination IP address.
-The netmask is specified either as a number of bits with
-.Ar /nn
-or as an IP number using
-.Ar mask .
-.Ar 0 0
-or simply
-.Ar 0
-with no mask refers to the default route.
-It is also possible to use the literal name
-.Sq default
-instead of
-.Ar 0 .
-.Ar Gateway
-is the next hop gateway to get to the given
-.Ar dest
-machine/network.
-Refer to the
-.Xr route 8
-command for further details.
-.Pp
-It is possible to use the symbolic names
-.Sq MYADDR
-or
-.Sq HISADDR
-as the destination, and
-.Sq HISADDR
-as the
-.Ar gateway .
-.Sq MYADDR
-is replaced with the interface address and
-.Sq HISADDR
-is replaced with the interface destination (peer) address.
-.Pp
-If the
-.Ar add!\&
-command is used
-(note the trailing
-.Dq !\& ) ,
-then if the route already exists, it will be updated as with the
-.Sq route change
-command (see
-.Xr route 8
-for further details).
-.Pp
-Routes that contain the
-.Dq HISADDR ,
-.Dq MYADDR ,
-.Dq DNS0 ,
-or
-.Dq DNS1
-constants are considered
-.Sq sticky .
-They are stored in a list (use
-.Dq show ipcp
-to see the list), and each time the value of
-.Dv HISADDR ,
-.Dv MYADDR ,
-.Dv DNS0 ,
-or
-.Dv DNS1
-changes, the appropriate routing table entries are updated.
-This facility may be disabled using
-.Dq disable sroutes .
-.It allow Ar command Op Ar args
-This command controls access to
-.Nm
-and its configuration files.
-It is possible to allow user-level access,
-depending on the configuration file label and on the mode that
-.Nm
-is being run in.
-For example, you may wish to configure
-.Nm
-so that only user
-.Sq fred
-may access label
-.Sq fredlabel
-in
-.Fl background
-mode.
-.Pp
-User id 0 is immune to these commands.
-.Bl -tag -width 2n
-.It allow user Ns Xo
-.Op s
-.Ar logname Ns No ...
-.Xc
-By default, only user id 0 is allowed access to
-.Nm .
-If this command is used, all of the listed users are allowed access to
-the section in which the
-.Dq allow users
-command is found.
-The
-.Sq default
-section is always checked first (even though it is only ever automatically
-loaded at startup).
-.Dq allow users
-commands are cumulative in a given section, but users allowed in any given
-section override users allowed in the default section, so it's possible to
-allow users access to everything except a given label by specifying default
-users in the
-.Sq default
-section, and then specifying a new user list for that label.
-.Pp
-If user
-.Sq *
-is specified, access is allowed to all users.
-.It allow mode Ns Xo
-.Op s
-.Ar mode Ns No ...
-.Xc
-By default, access using any
-.Nm
-mode is possible.
-If this command is used, it restricts the access
-.Ar modes
-allowed to load the label under which this command is specified.
-Again, as with the
-.Dq allow users
-command, each
-.Dq allow modes
-command overrides any previous settings, and the
-.Sq default
-section is always checked first.
-.Pp
-Possible modes are:
-.Sq interactive ,
-.Sq auto ,
-.Sq direct ,
-.Sq dedicated ,
-.Sq ddial ,
-.Sq background
-and
-.Sq * .
-.Pp
-When running in multi-link mode, a section can be loaded if it allows
-.Em any
-of the currently existing line modes.
-.El
-.Pp
-.It nat Ar command Op Ar args
-This command allows the control of the network address translation (also
-known as masquerading or IP aliasing) facilities that are built into
-.Nm .
-NAT is done on the external interface only, and is unlikely to make sense
-if used with the
-.Fl direct
-flag.
-.Pp
-If nat is enabled on your system (it may be omitted at compile time),
-the following commands are possible:
-.Bl -tag -width 2n
-.It nat enable yes|no
-This command either switches network address translation on or turns it off.
-The
-.Fl nat
-command line flag is synonymous with
-.Dq nat enable yes .
-.It nat addr Op Ar addr_local addr_alias
-This command allows data for
-.Ar addr_alias
-to be redirected to
-.Ar addr_local .
-It is useful if you own a small number of real IP numbers that
-you wish to map to specific machines behind your gateway.
-.It nat deny_incoming yes|no
-If set to yes, this command will refuse all incoming packets where an
-aliasing link doesn't already exist.
-Refer to the
-.Sx CONCEPTUAL BACKGROUND
-section of
-.Xr libalias 3
-for a description of what an
-.Dq aliasing link
-is.
-.Pp
-It should be noted under what circumstances an aliasing link is created by
-.Xr libalias 3 .
-It may be necessary to further protect your network from outside
-connections using the
-.Dq set filter
-or
-.Dq nat target
-commands.
-.It nat help|?
-This command gives a summary of available nat commands.
-.It nat log yes|no
-This option causes various NAT statistics and information to
-be logged to the file
-.Pa /var/log/alias.log .
-.It nat port Ar proto Ar targetIP Ns Xo
-.No : Ns Ar targetPort Ns
-.Oo
-.No - Ns Ar targetPort
-.Oc Ar aliasPort Ns
-.Oo
-.No - Ns Ar aliasPort
-.Oc Oo Ar remoteIP : Ns
-.Ar remotePort Ns
-.Oo
-.No - Ns Ar remotePort
-.Oc Ns
-.Oc
-.Xc
-This command causes incoming
-.Ar proto
-connections to
-.Ar aliasPort
-to be redirected to
-.Ar targetPort
-on
-.Ar targetIP .
-.Ar proto
-is either
-.Dq tcp
-or
-.Dq udp .
-.Pp
-A range of port numbers may be specified as shown above.
-The ranges must be of the same size.
-.Pp
-If
-.Ar remoteIP
-is specified, only data coming from that IP number is redirected.
-.Ar remotePort
-must either be
-.Dq 0
-(indicating any source port)
-or a range of ports the same size as the other ranges.
-.Pp
-This option is useful if you wish to run things like Internet phone on
-machines behind your gateway, but is limited in that connections to only
-one interior machine per source machine and target port are possible.
-.It nat proto Ar proto localIP Oo
-.Ar publicIP Op Ar remoteIP
-.Oc
-This command tells
-.Nm
-to redirect packets of protocol type
-.Ar proto
-(see
-.Xr protocols 5 )
-to the internall address
-.Ar localIP .
-.Pp
-If
-.Ar publicIP
-is specified, only packets destined for that address are matched,
-otherwise the default alias address is used.
-.Pp
-If
-.Ar remoteIP
-is specified, only packets matching that source address are matched,
-.Pp
-This command is useful for redirecting tunnel endpoints to an internal machine,
-for example:
-.Pp
-.Dl nat proto ipencap 10.0.0.1
-.It "nat proxy cmd" Ar arg Ns No ...
-This command tells
-.Nm
-to proxy certain connections, redirecting them to a given server.
-Refer to the description of
-.Fn PacketAliasProxyRule
-in
-.Xr libalias 3
-for details of the available commands.
-.It nat punch_fw Op Ar base count
-This command tells
-.Nm
-to punch holes in the firewall for FTP or IRC DCC connections.
-This is done dynamically by installing termporary firewall rules which
-allow a particular connection (and only that connection) to go through
-the firewall.
-The rules are removed once the corresponding connection terminates.
-.Pp
-A maximum of
-.Ar count
-rules starting from rule number
-.Ar base
-will be used for punching firewall holes.
-The range will be cleared when the
-.Dq nat punch_fw
-command is run.
-.Pp
-If no arguments are given, firewall punching is disabled.
-.It nat same_ports yes|no
-When enabled, this command will tell the network address translation engine to
-attempt to avoid changing the port number on outgoing packets.
-This is useful
-if you want to support protocols such as RPC and LPD which require
-connections to come from a well known port.
-.It nat target Op Ar address
-Set the given target address or clear it if no address is given.
-The target address is used by libalias to specify how to NAT incoming
-packets by default.
-If a target address is not set or if
-.Dq default
-is given, packets are not altered and are allowed to route to the internal
-network.
-.Pp
-The target address may be set to
-.Dq MYADDR ,
-in which case libalias will redirect all packets to the interface address.
-.It nat use_sockets yes|no
-When enabled, this option tells the network address translation engine to
-create a socket so that it can guarantee a correct incoming ftp data or
-IRC connection.
-.It nat unregistered_only yes|no
-Only alter outgoing packets with an unregistered source address.
-According to RFC 1918, unregistered source addresses
-are 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16.
-.El
-.Pp
-These commands are also discussed in the file
-.Pa README.nat
-which comes with the source distribution.
-.Pp
-.It Op !\& Ns Xo
-.No bg Ar command
-.Xc
-The given
-.Ar command
-is executed in the background with the following words replaced:
-.Bl -tag -width PEER_ENDDISC
-.It Li AUTHNAME
-This is replaced with the local
-.Ar authname
-value.
-See the
-.Dq set authname
-command below.
-.It Li COMPILATIONDATE
-This is replaced with the date on which
-.Nm
-was compiled.
-.It Li DNS0 & DNS1
-These are replaced with the primary and secondary nameserver IP numbers.
-If nameservers are negotiated by IPCP, the values of these macros will change.
-.It Li ENDDISC
-This is replaced with the local endpoint discriminator value.
-See the
-.Dq set enddisc
-command below.
-.It Li HISADDR
-This is replaced with the peers IP number.
-.It Li INTERFACE
-This is replaced with the name of the interface that's in use.
-.It Li LABEL
-This is replaced with the last label name used.
-A label may be specified on the
-.Nm
-command line, via the
-.Dq load
-or
-.Dq dial
-commands and in the
-.Pa ppp.secret
-file.
-.It Li MYADDR
-This is replaced with the IP number assigned to the local interface.
-.It Li PEER_ENDDISC
-This is replaced with the value of the peers endpoint discriminator.
-.It Li PROCESSID
-This is replaced with the current process id.
-.It Li VERSION
-This is replaced with the current version number of
-.Nm .
-.It Li USER
-This is replaced with the username that has been authenticated with PAP or
-CHAP.
-Normally, this variable is assigned only in -direct mode.
-This value is available irrespective of whether utmp logging is enabled.
-.El
-.Pp
-These substitutions are also done by the
-.Dq set proctitle
-command.
-.Pp
-If you wish to pause
-.Nm
-while the command executes, use the
-.Dq shell
-command instead.
-.It clear physical|ipcp Op current|overall|peak...
-Clear the specified throughput values at either the
-.Dq physical
-or
-.Dq ipcp
-level.
-If
-.Dq physical
-is specified, context must be given (see the
-.Dq link
-command below).
-If no second argument is given, all values are cleared.
-.It clone Ar name Ns Xo
-.Op \&, Ns Ar name Ns
-.No ...
-.Xc
-Clone the specified link, creating one or more new links according to the
-.Ar name
-argument(s).
-This command must be used from the
-.Dq link
-command below unless you've only got a single link (in which case that
-link becomes the default).
-Links may be removed using the
-.Dq remove
-command below.
-.Pp
-The default link name is
-.Dq deflink .
-.It close Op lcp|ccp Ns Op !\&
-If no arguments are given, the relevant protocol layers will be brought
-down and the link will be closed.
-If
-.Dq lcp
-is specified, the LCP layer is brought down, but
-.Nm
-will not bring the link offline.
-It is subsequently possible to use
-.Dq term
-(see below)
-to talk to the peer machine if, for example, something like
-.Dq slirp
-is being used.
-If
-.Dq ccp
-is specified, only the relevant compression layer is closed.
-If the
-.Dq !\&
-is used, the compression layer will remain in the closed state, otherwise
-it will re-enter the STOPPED state, waiting for the peer to initiate
-further CCP negotiation.
-In any event, this command does not disconnect the user from
-.Nm
-or exit
-.Nm .
-See the
-.Dq quit
-command below.
-.It delete Ns Xo
-.Op !\&
-.Ar dest
-.Xc
-This command deletes the route with the given
-.Ar dest
-IP address.
-If
-.Ar dest
-is specified as
-.Sq ALL ,
-all non-direct entries in the routing table for the current interface,
-and all
-.Sq sticky route
-entries are deleted.
-If
-.Ar dest
-is specified as
-.Sq default ,
-the default route is deleted.
-.Pp
-If the
-.Ar delete!\&
-command is used
-(note the trailing
-.Dq !\& ) ,
-.Nm
-will not complain if the route does not already exist.
-.It dial|call Op Ar label Ns Xo
-.No ...
-.Xc
-This command is the equivalent of
-.Dq load label
-followed by
-.Dq open ,
-and is provided for backwards compatibility.
-.It down Op Ar lcp|ccp
-Bring the relevant layer down ungracefully, as if the underlying layer
-had become unavailable.
-It's not considered polite to use this command on
-a Finite State Machine that's in the OPEN state.
-If no arguments are
-supplied, the entire link is closed (or if no context is given, all links
-are terminated).
-If
-.Sq lcp
-is specified, the
-.Em LCP
-layer is terminated but the device is not brought offline and the link
-is not closed.
-If
-.Sq ccp
-is specified, only the relevant compression layer(s) are terminated.
-.It help|? Op Ar command
-Show a list of available commands.
-If
-.Ar command
-is specified, show the usage string for that command.
-.It ident Op Ar text Ns No ...
-Identify the link to the peer using
-.Ar text .
-If
-.Ar text
-is empty, link identification is disabled.
-It is possible to use any of the words described for the
-.Ic bg
-command above.
-Refer to the
-.Ic sendident
-command for details of when
-.Nm
-identifies itself to the peer.
-.It iface Ar command Op args
-This command is used to control the interface used by
-.Nm .
-.Ar Command
-may be one of the following:
-.Bl -tag -width 2n
-.It iface add Ns Xo
-.Op !\&
-.Ar addr Ns Op / Ns Ar bits
-.Op Ar peer
-.Xc
-.It iface add Ns Xo
-.Op !\&
-.Ar addr
-.Ar mask
-.Ar peer
-.Xc
-Add the given
-.Ar addr mask peer
-combination to the interface.
-Instead of specifying
-.Ar mask ,
-.Ar /bits
-can be used
-(with no space between it and
-.Ar addr ) .
-If the given address already exists, the command fails unless the
-.Dq !\&
-is used - in which case the previous interface address entry is overwritten
-with the new one, allowing a change of netmask or peer address.
-.Pp
-If only
-.Ar addr
-is specified,
-.Ar bits
-defaults to
-.Dq 32
-and
-.Ar peer
-defaults to
-.Dq 255.255.255.255 .
-This address (the broadcast address) is the only duplicate peer address that
-.Nm
-allows.
-.It iface clear
-If this command is used while
-.Nm
-is in the OPENED state or while in
-.Fl auto
-mode, all addresses except for the IPCP negotiated address are deleted
-from the interface.
-If
-.Nm
-is not in the OPENED state and is not in
-.Fl auto
-mode, all interface addresses are deleted.
-.Pp
-.It iface delete Ns Xo
-.Op !\& Ns
-.No |rm Ns Op !\&
-.Ar addr
-.Xc
-This command deletes the given
-.Ar addr
-from the interface.
-If the
-.Dq !\&
-is used, no error is given if the address isn't currently assigned to
-the interface (and no deletion takes place).
-.It iface show
-Shows the current state and current addresses for the interface.
-It is much the same as running
-.Dq ifconfig INTERFACE .
-.It iface help Op Ar sub-command
-This command, when invoked without
-.Ar sub-command ,
-will show a list of possible
-.Dq iface
-sub-commands and a brief synopsis for each.
-When invoked with
-.Ar sub-command ,
-only the synopsis for the given sub-command is shown.
-.El
-.It Op data Ns Xo
-.No link
-.Ar name Ns Op , Ns Ar name Ns
-.No ... Ar command Op Ar args
-.Xc
-This command may prefix any other command if the user wishes to
-specify which link the command should affect.
-This is only applicable after multiple links have been created in Multi-link
-mode using the
-.Dq clone
-command.
-.Pp
-.Ar Name
-specifies the name of an existing link.
-If
-.Ar name
-is a comma separated list,
-.Ar command
-is executed on each link.
-If
-.Ar name
-is
-.Dq * ,
-.Ar command
-is executed on all links.
-.It load Op Ar label Ns Xo
-.No ...
-.Xc
-Load the given
-.Ar label Ns No (s)
-from the
-.Pa ppp.conf
-file.
-If
-.Ar label
-is not given, the
-.Ar default
-label is used.
-.Pp
-Unless the
-.Ar label
-section uses the
-.Dq set mode ,
-.Dq open
-or
-.Dq dial
-commands,
-.Nm
-will not attempt to make an immediate connection.
-.It open Op lcp|ccp|ipcp
-This is the opposite of the
-.Dq close
-command.
-All closed links are immediately brought up apart from second and subsequent
-.Ar demand-dial
-links - these will come up based on the
-.Dq set autoload
-command that has been used.
-.Pp
-If the
-.Dq lcp
-argument is used while the LCP layer is already open, LCP will be
-renegotiated.
-This allows various LCP options to be changed, after which
-.Dq open lcp
-can be used to put them into effect.
-After renegotiating LCP,
-any agreed authentication will also take place.
-.Pp
-If the
-.Dq ccp
-argument is used, the relevant compression layer is opened.
-Again, if it is already open, it will be renegotiated.
-.Pp
-If the
-.Dq ipcp
-argument is used, the link will be brought up as normal, but if
-IPCP is already open, it will be renegotiated and the network
-interface will be reconfigured.
-.Pp
-It is probably not good practice to re-open the PPP state machines
-like this as it's possible that the peer will not behave correctly.
-It
-.Em is
-however useful as a way of forcing the CCP or VJ dictionaries to be reset.
-.It passwd Ar pass
-Specify the password required for access to the full
-.Nm
-command set.
-This password is required when connecting to the diagnostic port (see the
-.Dq set server
-command).
-.Ar Pass
-is specified on the
-.Dq set server
-command line.
-The value of
-.Ar pass
-is not logged when
-.Ar command
-logging is active, instead, the literal string
-.Sq ********
-is logged.
-.It quit|bye Op all
-If
-.Dq quit
-is executed from the controlling connection or from a command file,
-ppp will exit after closing all connections.
-Otherwise, if the user
-is connected to a diagnostic socket, the connection is simply dropped.
-.Pp
-If the
-.Ar all
-argument is given,
-.Nm
-will exit despite the source of the command after closing all existing
-connections.
-.It remove|rm
-This command removes the given link.
-It is only really useful in multi-link mode.
-A link must be in the
-.Dv CLOSED
-state before it is removed.
-.It rename|mv Ar name
-This command renames the given link to
-.Ar name .
-It will fail if
-.Ar name
-is already used by another link.
-.Pp
-The default link name is
-.Sq deflink .
-Renaming it to
-.Sq modem ,
-.Sq cuaa0
-or
-.Sq USR
-may make the log file more readable.
-.It resolv Ar command
-This command controls
-.Nm Ns No 's
-manipulation of the
-.Xr resolv.conf 5
-file.
-When
-.Nm
-starts up, it loads the contents of this file into memory and retains this
-image for future use.
-.Ar command
-is one of the following:
-.Bl -tag -width readonly
-.It Em readonly
-Treat
-.Pa /etc/resolv.conf
-as read only.
-If
-.Dq dns
-is enabled,
-.Nm
-will still attempt to negotiate nameservers with the peer, making the results
-available via the
-.Dv DNS0
-and
-.Dv DNS1
-macros.
-This is the opposite of the
-.Dq resolv writable
-command.
-.It Em reload
-Reload
-.Pa /etc/resolv.conf
-into memory.
-This may be necessary if for example a DHCP client overwrote
-.Pa /etc/resolv.conf .
-.It Em restore
-Replace
-.Pa /etc/resolv.conf
-with the version originally read at startup or with the last
-.Dq resolv reload
-command.
-This is sometimes a useful command to put in the
-.Pa /etc/ppp/ppp.linkdown
-file.
-.It Em rewrite
-Rewrite the
-.Pa /etc/resolv.conf
-file.
-This command will work even if the
-.Dq resolv readonly
-command has been used.
-It may be useful as a command in the
-.Pa /etc/ppp/ppp.linkup
-file if you wish to defer updating
-.Pa /etc/resolv.conf
-until after other commands have finished.
-.It Em writable
-Allow
-.Nm
-to update
-.Pa /etc/resolv.conf
-if
-.Dq dns
-is enabled and
-.Nm
-successfully negotiates a DNS.
-This is the opposite of the
-.Dq resolv readonly
-command.
-.El
-.It save
-This option is not (yet) implemented.
-.It sendident
-This command tells
-.Nm
-to identify itself to the peer.
-The link must be in LCP state or higher.
-If no identity has been set (via the
-.Ic ident
-command),
-.Ic sendident
-will fail.
-.Pp
-When an identity has been set,
-.Nm
-will automatically identify itself when it sends or receives a configure
-reject, when negotiation fails or when LCP reaches the opened state.
-.Pp
-Received identification packets are logged to the LCP log (see
-.Ic set log
-for details) and are never responded to.
-.It set Ns Xo
-.Op up
-.Ar var value
-.Xc
-This option allows the setting of any of the following variables:
-.Bl -tag -width 2n
-.It set accmap Ar hex-value
-ACCMap stands for Asynchronous Control Character Map.
-This is always
-negotiated with the peer, and defaults to a value of 00000000 in hex.
-This protocol is required to defeat hardware that depends on passing
-certain characters from end to end (such as XON/XOFF etc).
-.Pp
-For the XON/XOFF scenario, use
-.Dq set accmap 000a0000 .
-.It set Op auth Ns Xo
-.No key Ar value
-.Xc
-This sets the authentication key (or password) used in client mode
-PAP or CHAP negotiation to the given value.
-It also specifies the
-password to be used in the dial or login scripts in place of the
-.Sq \eP
-sequence, preventing the actual password from being logged.
-If
-.Ar command
-or
-.Ar chat
-logging is in effect,
-.Ar value
-is logged as
-.Sq ********
-for security reasons.
-.Pp
-If the first character of
-.Ar value
-is an exclamation mark
-.Pq Dq !\& ,
-.Nm
-treats the remainder of the string as a program that must be executed
-to determine the
-.Dq authname
-and
-.Dq authkey
-values.
-.Pp
-If the
-.Dq !\&
-is doubled up
-(to
-.Dq !! ) ,
-it is treated as a single literal
-.Dq !\& ,
-otherwise, ignoring the
-.Dq !\& ,
-.Ar value
-is parsed as a program to execute in the same was as the
-.Dq !bg
-command above, substituting special names in the same manner.
-Once executed,
-.Nm
-will feed the program three lines of input, each terminated by a newline
-character:
-.Bl -bullet
-.It
-The host name as sent in the CHAP challenge.
-.It
-The challenge string as sent in the CHAP challenge.
-.It
-The locally defined
-.Dq authname .
-.El
-.Pp
-Two lines of output are expected:
-.Bl -bullet
-.It
-The
-.Dq authname
-to be sent with the CHAP response.
-.It
-The
-.Dq authkey ,
-which is encrypted with the challenge and request id, the answer being sent
-in the CHAP response packet.
-.El
-.Pp
-When configuring
-.Nm
-in this manner, it's expected that the host challenge is a series of ASCII
-digits or characters.
-An encryption device or Secure ID card is usually
-required to calculate the secret appropriate for the given challenge.
-.It set authname Ar id
-This sets the authentication id used in client mode PAP or CHAP negotiation.
-.Pp
-If used in
-.Fl direct
-mode with CHAP enabled,
-.Ar id
-is used in the initial authentication challenge and should normally be set to
-the local machine name.
-.It set autoload Xo
-.Ar min-percent max-percent period
-.Xc
-These settings apply only in multi-link mode and default to zero, zero and
-five respectively.
-When more than one
-.Ar demand-dial
-(also known as
-.Fl auto )
-mode link is available, only the first link is made active when
-.Nm
-first reads data from the tun device.
-The next
-.Ar demand-dial
-link will be opened only when the current bundle throughput is at least
-.Ar max-percent
-percent of the total bundle bandwidth for
-.Ar period
-seconds.
-When the current bundle throughput decreases to
-.Ar min-percent
-percent or less of the total bundle bandwidth for
-.Ar period
-seconds, a
-.Ar demand-dial
-link will be brought down as long as it's not the last active link.
-.Pp
-Bundle throughput is measured as the maximum of inbound and outbound
-traffic.
-.Pp
-The default values cause
-.Ar demand-dial
-links to simply come up one at a time.
-.Pp
-Certain devices cannot determine their physical bandwidth, so it
-is sometimes necessary to use the
-.Dq set bandwidth
-command (described below) to make
-.Dq set autoload
-work correctly.
-.It set bandwidth Ar value
-This command sets the connection bandwidth in bits per second.
-.Ar value
-must be greater than zero.
-It is currently only used by the
-.Dq set autoload
-command above.
-.It set callback Ar option Ns No ...
-If no arguments are given, callback is disabled, otherwise,
-.Nm
-will request (or in
-.Fl direct
-mode, will accept) one of the given
-.Ar option Ns No s .
-In client mode, if an
-.Ar option
-is NAK'd
-.Nm
-will request a different
-.Ar option ,
-until no options remain at which point
-.Nm
-will terminate negotiations (unless
-.Dq none
-is one of the specified
-.Ar option ) .
-In server mode,
-.Nm
-will accept any of the given protocols - but the client
-.Em must
-request one of them.
-If you wish callback to be optional, you must include
-.Ar none
-as an option.
-.Pp
-The
-.Ar option Ns No s
-are as follows (in this order of preference):
-.Pp
-.Bl -tag -width Ds
-.It auth
-The callee is expected to decide the callback number based on
-authentication.
-If
-.Nm
-is the callee, the number should be specified as the fifth field of
-the peers entry in
-.Pa /etc/ppp/ppp.secret .
-.It cbcp
-Microsoft's callback control protocol is used.
-See
-.Dq set cbcp
-below.
-.Pp
-If you wish to negotiate
-.Ar cbcp
-in client mode but also wish to allow the server to request no callback at
-CBCP negotiation time, you must specify both
-.Ar cbcp
-and
-.Ar none
-as callback options.
-.It E.164 *| Ns Xo
-.Ar number Ns Op , Ns Ar number Ns
-.No ...
-.Xc
-The caller specifies the
-.Ar number .
-If
-.Nm
-is the callee,
-.Ar number
-should be either a comma separated list of allowable numbers or a
-.Dq \&* ,
-meaning any number is permitted.
-If
-.Nm
-is the caller, only a single number should be specified.
-.Pp
-Note, this option is very unsafe when used with a
-.Dq \&*
-as a malicious caller can tell
-.Nm
-to call any (possibly international) number without first authenticating
-themselves.
-.It none
-If the peer does not wish to do callback at all,
-.Nm
-will accept the fact and continue without callback rather than terminating
-the connection.
-This is required (in addition to one or more other callback
-options) if you wish callback to be optional.
-.El
-.Pp
-.It set cbcp Oo
-.No *| Ns Ar number Ns Oo
-.No , Ns Ar number Ns ...\& Oc
-.Op Ar delay Op Ar retry
-.Oc
-If no arguments are given, CBCP (Microsoft's CallBack Control Protocol)
-is disabled - ie, configuring CBCP in the
-.Dq set callback
-command will result in
-.Nm
-requesting no callback in the CBCP phase.
-Otherwise,
-.Nm
-attempts to use the given phone
-.Ar number Ns No (s).
-.Pp
-In server mode
-.Pq Fl direct ,
-.Nm
-will insist that the client uses one of these numbers, unless
-.Dq \&*
-is used in which case the client is expected to specify the number.
-.Pp
-In client mode,
-.Nm
-will attempt to use one of the given numbers (whichever it finds to
-be agreeable with the peer), or if
-.Dq \&*
-is specified,
-.Nm
-will expect the peer to specify the number.
-.It set cd Oo
-.No off| Ns Ar seconds Ns Op !\&
-.Oc
-Normally,
-.Nm
-checks for the existence of carrier depending on the type of device
-that has been opened:
-.Bl -tag -width XXX -offset XXX
-.It Terminal Devices
-Carrier is checked one second after the login script is complete.
-If it's not set,
-.Nm
-assumes that this is because the device doesn't support carrier (which
-is true for most
-.Dq laplink
-NULL-modem cables), logs the fact and stops checking
-for carrier.
-.Pp
-As ptys don't support the TIOCMGET ioctl, the tty device will switch all
-carrier detection off when it detects that the device is a pty.
-.It ISDN (i4b) Devices
-Carrier is checked once per second for 6 seconds.
-If it's not set after
-the sixth second, the connection attempt is considered to have failed and
-the device is closed.
-Carrier is always required for i4b devices.
-.It PPPoE (netgraph) Devices
-Carrier is checked once per second for 5 seconds.
-If it's not set after
-the fifth second, the connection attempt is considered to have failed and
-the device is closed.
-Carrier is always required for PPPoE devices.
-.El
-.Pp
-All other device types don't support carrier.
-Setting a carrier value will
-result in a warning when the device is opened.
-.Pp
-Some modems take more than one second after connecting to assert the carrier
-signal.
-If this delay isn't increased, this will result in
-.Nm Ns No 's
-inability to detect when the link is dropped, as
-.Nm
-assumes that the device isn't asserting carrier.
-.Pp
-The
-.Dq set cd
-command overrides the default carrier behaviour.
-.Ar seconds
-specifies the maximum number of seconds that
-.Nm
-should wait after the dial script has finished before deciding if
-carrier is available or not.
-.Pp
-If
-.Dq off
-is specified,
-.Nm
-will not check for carrier on the device, otherwise
-.Nm
-will not proceed to the login script until either carrier is detected
-or until
-.Ar seconds
-has elapsed, at which point
-.Nm
-assumes that the device will not set carrier.
-.Pp
-If no arguments are given, carrier settings will go back to their default
-values.
-.Pp
-If
-.Ar seconds
-is followed immediately by an exclamation mark
-.Pq Dq !\& ,
-.Nm
-will
-.Em require
-carrier.
-If carrier is not detected after
-.Ar seconds
-seconds, the link will be disconnected.
-.It set choked Op Ar timeout
-This sets the number of seconds that
-.Nm
-will keep a choked output queue before dropping all pending output packets.
-If
-.Ar timeout
-is less than or equal to zero or if
-.Ar timeout
-isn't specified, it is set to the default value of
-.Em 120 seconds .
-.Pp
-A choked output queue occurs when
-.Nm
-has read a certain number of packets from the local network for transmission,
-but cannot send the data due to link failure (the peer is busy etc.).
-.Nm
-will not read packets indefinitely.
-Instead, it reads up to
-.Em 30
-packets (or
-.Em 30 No +
-.Em nlinks No *
-.Em 2
-packets in multi-link mode), then stops reading the network interface
-until either
-.Ar timeout
-seconds have passed or at least one packet has been sent.
-.Pp
-If
-.Ar timeout
-seconds pass, all pending output packets are dropped.
-.It set ctsrts|crtscts on|off
-This sets hardware flow control.
-Hardware flow control is
-.Ar on
-by default.
-.It set deflate Ar out-winsize Op Ar in-winsize
-This sets the DEFLATE algorithms default outgoing and incoming window
-sizes.
-Both
-.Ar out-winsize
-and
-.Ar in-winsize
-must be values between
-.Em 8
-and
-.Em 15 .
-If
-.Ar in-winsize
-is specified,
-.Nm
-will insist that this window size is used and will not accept any other
-values from the peer.
-.It set dns Op Ar primary Op Ar secondary
-This command specifies DNS overrides for the
-.Dq accept dns
-command.
-Refer to the
-.Dq accept
-command description above for details.
-This command does not affect the IP numbers requested using
-.Dq enable dns .
-.It set device|line Xo
-.Ar value Ns No ...
-.Xc
-This sets the device(s) to which
-.Nm
-will talk to the given
-.Dq value .
-.Pp
-All ISDN and serial device names are expected to begin with
-.Pa /dev/ .
-ISDN devices are usually called
-.Pa i4brbchX
-and serial devices are usually called
-.Pa cuaXX .
-.Pp
-If
-.Dq value
-does not begin with
-.Pa /dev/ ,
-it must either begin with an exclamation mark
-.Pq Dq !\& ,
-be of the format
-.No PPPoE: Ns Ar iface Ns Xo
-.Op \&: Ns Ar provider Ns
-.Xc
-(on
-.Xr netgraph 4
-enabled systems), or be of the format
-.Sm off
-.Ar host : port Op /tcp|udp .
-.Sm on
-.Pp
-If it begins with an exclamation mark, the rest of the device name is
-treated as a program name, and that program is executed when the device
-is opened.
-Standard input, output and error are fed back to
-.Nm
-and are read and written as if they were a regular device.
-.Pp
-If a
-.No PPPoE: Ns Ar iface Ns Xo
-.Op \&: Ns Ar provider Ns
-.Xc
-specification is given,
-.Nm
-will attempt to create a
-.Em PPP
-over Ethernet connection using the given
-.Ar iface
-interface by using
-.Xr netgraph 4 .
-If
-.Xr netgraph 4
-is not available,
-.Nm
-will attempt to load it using
-.Xr kldload 2 .
-If this fails, an external program must be used such as the
-.Xr pppoe 8
-program available under OpenBSD.
-The given
-.Ar provider
-is passed as the service name in the PPPoE Discovery Initiation (PADI)
-packet.
-If no provider is given, an empty value will be used.
-Refer to
-.Xr netgraph 4
-and
-.Xr ng_pppoe 4
-for further details.
-.Pp
-If a
-.Ar host Ns No : Ns Ar port Ns Oo
-.No /tcp|udp
-.Oc
-specification is given,
-.Nm
-will attempt to connect to the given
-.Ar host
-on the given
-.Ar port .
-If a
-.Dq /tcp
-or
-.Dq /udp
-suffix is not provided, the default is
-.Dq /tcp .
-Refer to the section on
-.Em PPP OVER TCP and UDP
-above for further details.
-.Pp
-If multiple
-.Dq values
-are specified,
-.Nm
-will attempt to open each one in turn until it succeeds or runs out of
-devices.
-.It set dial Ar chat-script
-This specifies the chat script that will be used to dial the other
-side.
-See also the
-.Dq set login
-command below.
-Refer to
-.Xr chat 8
-and to the example configuration files for details of the chat script
-format.
-It is possible to specify some special
-.Sq values
-in your chat script as follows:
-.Bl -tag -width 2n
-.It Li \ec
-When used as the last character in a
-.Sq send
-string, this indicates that a newline should not be appended.
-.It Li \ed
-When the chat script encounters this sequence, it delays two seconds.
-.It Li \ep
-When the chat script encounters this sequence, it delays for one quarter of
-a second.
-.It Li \en
-This is replaced with a newline character.
-.It Li \er
-This is replaced with a carriage return character.
-.It Li \es
-This is replaced with a space character.
-.It Li \et
-This is replaced with a tab character.
-.It Li \eT
-This is replaced by the current phone number (see
-.Dq set phone
-below).
-.It Li \eP
-This is replaced by the current
-.Ar authkey
-value (see
-.Dq set authkey
-above).
-.It Li \eU
-This is replaced by the current
-.Ar authname
-value (see
-.Dq set authname
-above).
-.El
-.Pp
-Note that two parsers will examine these escape sequences, so in order to
-have the
-.Sq chat parser
-see the escape character, it is necessary to escape it from the
-.Sq command parser .
-This means that in practice you should use two escapes, for example:
-.Bd -literal -offset indent
-set dial "... ATDT\\\\T CONNECT"
-.Ed
-.Pp
-It is also possible to execute external commands from the chat script.
-To do this, the first character of the expect or send string is an
-exclamation mark
-.Pq Dq !\& .
-If a literal exclamation mark is required, double it up to
-.Dq !!\&
-and it will be treated as a single literal
-.Dq !\& .
-When the command is executed, standard input and standard output are
-directed to the open device (see the
-.Dq set device
-command), and standard error is read by
-.Nm
-and substituted as the expect or send string.
-If
-.Nm
-is running in interactive mode, file descriptor 3 is attached to
-.Pa /dev/tty .
-.Pp
-For example (wrapped for readability):
-.Bd -literal -offset indent
-set login "TIMEOUT 5 \\"\\" \\"\\" login:--login: ppp \e
-word: ppp \\"!sh \\\\-c \\\\\\"echo \\\\-n label: >&2\\\\\\"\\" \e
-\\"!/bin/echo in\\" HELLO"
-.Ed
-.Pp
-would result in the following chat sequence (output using the
-.Sq set log local chat
-command before dialing):
-.Bd -literal -offset indent
-Dial attempt 1 of 1
-dial OK!
-Chat: Expecting:
-Chat: Sending:
-Chat: Expecting: login:--login:
-Chat: Wait for (5): login:
-Chat: Sending: ppp
-Chat: Expecting: word:
-Chat: Wait for (5): word:
-Chat: Sending: ppp
-Chat: Expecting: !sh \\-c "echo \\-n label: >&2"
-Chat: Exec: sh -c "echo -n label: >&2"
-Chat: Wait for (5): !sh \\-c "echo \\-n label: >&2" --> label:
-Chat: Exec: /bin/echo in
-Chat: Sending:
-Chat: Expecting: HELLO
-Chat: Wait for (5): HELLO
-login OK!
-.Ed
-.Pp
-Note (again) the use of the escape character, allowing many levels of
-nesting.
-Here, there are four parsers at work.
-The first parses the original line, reading it as three arguments.
-The second parses the third argument, reading it as 11 arguments.
-At this point, it is
-important that the
-.Dq \&-
-signs are escaped, otherwise this parser will see them as constituting
-an expect-send-expect sequence.
-When the
-.Dq !\&
-character is seen, the execution parser reads the first command as three
-arguments, and then
-.Xr sh 1
-itself expands the argument after the
-.Fl c .
-As we wish to send the output back to the modem, in the first example
-we redirect our output to file descriptor 2 (stderr) so that
-.Nm
-itself sends and logs it, and in the second example, we just output to stdout,
-which is attached directly to the modem.
-.Pp
-This, of course means that it is possible to execute an entirely external
-.Dq chat
-command rather than using the internal one.
-See
-.Xr chat 8
-for a good alternative.
-.Pp
-The external command that is executed is subjected to the same special
-word expansions as the
-.Dq !bg
-command.
-.It set enddisc Op label|IP|MAC|magic|psn value
-This command sets our local endpoint discriminator.
-If set prior to LCP negotiation, and if no
-.Dq disable enddisc
-command has been used,
-.Nm
-will send the information to the peer using the LCP endpoint discriminator
-option.
-The following discriminators may be set:
-.Bl -tag -width indent
-.It Li label
-The current label is used.
-.It Li IP
-Our local IP number is used.
-As LCP is negotiated prior to IPCP, it is
-possible that the IPCP layer will subsequently change this value.
-If
-it does, the endpoint discriminator stays at the old value unless manually
-reset.
-.It Li MAC
-This is similar to the
-.Ar IP
-option above, except that the MAC address associated with the local IP
-number is used.
-If the local IP number is not resident on any Ethernet
-interface, the command will fail.
-.Pp
-As the local IP number defaults to whatever the machine host name is,
-.Dq set enddisc mac
-is usually done prior to any
-.Dq set ifaddr
-commands.
-.It Li magic
-A 20 digit random number is used.
-Care should be taken when using magic numbers as restarting
-.Nm
-or creating a link using a different
-.Nm
-invocation will also use a different magic number and will therefore not
-be recognised by the peer as belonging to the same bundle.
-This makes it unsuitable for
-.Fl direct
-connections.
-.It Li psn Ar value
-The given
-.Ar value
-is used.
-.Ar Value
-should be set to an absolute public switched network number with the
-country code first.
-.El
-.Pp
-If no arguments are given, the endpoint discriminator is reset.
-.It set escape Ar value...
-This option is similar to the
-.Dq set accmap
-option above.
-It allows the user to specify a set of characters that will be
-.Sq escaped
-as they travel across the link.
-.It set filter dial|alive|in|out Ar rule-no Xo
-.No permit|deny|clear| Ns Ar rule-no
-.Op !\&
-.Oo Op host
-.Ar src_addr Ns Op / Ns Ar width
-.Op Ar dst_addr Ns Op / Ns Ar width
-.Oc [ tcp|udp|ospf|ipip|igmp|icmp Op src lt|eq|gt Ar port
-.Op dst lt|eq|gt Ar port
-.Op estab
-.Op syn
-.Op finrst
-.Op timeout Ar secs ]
-.Xc
-.Nm
-supports four filter sets.
-The
-.Em alive
-filter specifies packets that keep the connection alive - resetting the
-idle timer.
-The
-.Em dial
-filter specifies packets that cause
-.Nm
-to dial when in
-.Fl auto
-mode.
-The
-.Em in
-filter specifies packets that are allowed to travel
-into the machine and the
-.Em out
-filter specifies packets that are allowed out of the machine.
-.Pp
-Filtering is done prior to any IP alterations that might be done by the
-NAT engine on outgoing packets and after any IP alterations that might
-be done by the NAT engine on incoming packets.
-By default all empty filter sets allow all packets to pass.
-Rules are processed in order according to
-.Ar rule-no
-(unless skipped by specifying a rule number as the
-.Ar action ) .
-Up to 40 rules may be given for each set.
-If a packet doesn't match
-any of the rules in a given set, it is discarded.
-In the case of
-.Em in
-and
-.Em out
-filters, this means that the packet is dropped.
-In the case of
-.Em alive
-filters it means that the packet will not reset the idle timer (even if
-the
-.Ar in Ns No / Ns Ar out
-filter has a
-.Dq timeout
-value) and in the case of
-.Em dial
-filters it means that the packet will not trigger a dial.
-A packet failing to trigger a dial will be dropped rather than queued.
-Refer to the
-section on
-.Sx PACKET FILTERING
-above for further details.
-.It set hangup Ar chat-script
-This specifies the chat script that will be used to reset the device
-before it is closed.
-It should not normally be necessary, but can
-be used for devices that fail to reset themselves properly on close.
-.It set help|? Op Ar command
-This command gives a summary of available set commands, or if
-.Ar command
-is specified, the command usage is shown.
-.It set ifaddr Oo Ar myaddr Ns
-.Op / Ns Ar \&nn
-.Oo Ar hisaddr Ns Op / Ns Ar \&nn
-.Oo Ar netmask
-.Op Ar triggeraddr
-.Oc Oc
-.Oc
-This command specifies the IP addresses that will be used during
-IPCP negotiation.
-Addresses are specified using the format
-.Pp
-.Dl a.b.c.d/nn
-.Pp
-Where
-.Dq a.b.c.d
-is the preferred IP, but
-.Ar nn
-specifies how many bits of the address we will insist on.
-If
-.No / Ns Ar nn
-is omitted, it defaults to
-.Dq /32
-unless the IP address is 0.0.0.0 in which case it defaults to
-.Dq /0 .
-.Pp
-If you wish to assign a dynamic IP number to the peer,
-.Ar hisaddr
-may also be specified as a range of IP numbers in the format
-.Bd -ragged -offset indent
-.Ar \&IP Ns Oo \&- Ns Ar \&IP Ns Xo
-.Oc Ns Oo , Ns Ar \&IP Ns
-.Op \&- Ns Ar \&IP Ns
-.Oc Ns ...
-.Xc
-.Ed
-.Pp
-for example:
-.Pp
-.Dl set ifaddr 10.0.0.1 10.0.1.2-10.0.1.10,10.0.1.20
-.Pp
-will only negotiate
-.Dq 10.0.0.1
-as the local IP number, but may assign any of the given 10 IP
-numbers to the peer.
-If the peer requests one of these numbers,
-and that number is not already in use,
-.Nm
-will grant the peers request.
-This is useful if the peer wants
-to re-establish a link using the same IP number as was previously
-allocated (thus maintaining any existing tcp or udp connections).
-.Pp
-If the peer requests an IP number that's either outside
-of this range or is already in use,
-.Nm
-will suggest a random unused IP number from the range.
-.Pp
-If
-.Ar triggeraddr
-is specified, it is used in place of
-.Ar myaddr
-in the initial IPCP negotiation.
-However, only an address in the
-.Ar myaddr
-range will be accepted.
-This is useful when negotiating with some
-.Dv PPP
-implementations that will not assign an IP number unless their peer
-requests
-.Dq 0.0.0.0 .
-.Pp
-It should be noted that in
-.Fl auto
-mode,
-.Nm
-will configure the interface immediately upon reading the
-.Dq set ifaddr
-line in the config file.
-In any other mode, these values are just
-used for IPCP negotiations, and the interface isn't configured
-until the IPCP layer is up.
-.Pp
-Note that the
-.Ar HISADDR
-argument may be overridden by the third field in the
-.Pa ppp.secret
-file once the client has authenticated itself
-(if PAP or CHAP are
-.Dq enabled ) .
-Refer to the
-.Sx AUTHENTICATING INCOMING CONNECTIONS
-section for details.
-.Pp
-In all cases, if the interface is already configured,
-.Nm
-will try to maintain the interface IP numbers so that any existing
-bound sockets will remain valid.
-.It set ifqueue Ar packets
-Set the maximum number of packets that
-.Nm
-will read from the tunnel interface while data cannot be sent to any of
-the available links.
-This queue limit is necessary to flow control outgoing data as the tunnel
-interface is likely to be far faster than the combined links available to
-.Nm .
-.Pp
-If
-.Ar packets
-is set to a value less than the number of links,
-.Nm
-will read up to that value regardless.
-This prevents any possible latency problems.
-.Pp
-The default value for
-.Ar packets
-is
-.Dq 30 .
-.It set ccpretry|ccpretries Oo Ar timeout
-.Op Ar reqtries Op Ar trmtries
-.Oc
-.It set chapretry|chapretries Oo Ar timeout
-.Op Ar reqtries
-.Oc
-.It set ipcpretry|ipcpretries Oo Ar timeout
-.Op Ar reqtries Op Ar trmtries
-.Oc
-.It set lcpretry|lcpretries Oo Ar timeout
-.Op Ar reqtries Op Ar trmtries
-.Oc
-.It set papretry|papretries Oo Ar timeout
-.Op Ar reqtries
-.Oc
-These commands set the number of seconds that
-.Nm
-will wait before resending Finite State Machine (FSM) Request packets.
-The default
-.Ar timeout
-for all FSMs is 3 seconds (which should suffice in most cases).
-.Pp
-If
-.Ar reqtries
-is specified, it tells
-.Nm
-how many configuration request attempts it should make while receiving
-no reply from the peer before giving up.
-The default is 5 attempts for
-CCP, LCP and IPCP and 3 attempts for PAP and CHAP.
-.Pp
-If
-.Ar trmtries
-is specified, it tells
-.Nm
-how many terminate requests should be sent before giving up waiting for the
-peers response.
-The default is 3 attempts.
-Authentication protocols are
-not terminated and it is therefore invalid to specify
-.Ar trmtries
-for PAP or CHAP.
-.Pp
-In order to avoid negotiations with the peer that will never converge,
-.Nm
-will only send at most 3 times the configured number of
-.Ar reqtries
-in any given negotiation session before giving up and closing that layer.
-.It set log Xo
-.Op local
-.Op +|- Ns
-.Ar value Ns No ...
-.Xc
-This command allows the adjustment of the current log level.
-Refer to the Logging Facility section for further details.
-.It set login Ar chat-script
-This
-.Ar chat-script
-compliments the dial-script.
-If both are specified, the login
-script will be executed after the dial script.
-Escape sequences available in the dial script are also available here.
-.It set logout Ar chat-script
-This specifies the chat script that will be used to logout
-before the hangup script is called.
-It should not normally be necessary.
-.It set lqrperiod Ar frequency
-This command sets the
-.Ar frequency
-in seconds at which
-.Em LQR
-or
-.Em ECHO LQR
-packets are sent.
-The default is 30 seconds.
-You must also use the
-.Dq enable lqr
-command if you wish to send LQR requests to the peer.
-.It set mode Ar interactive|auto|ddial|background
-This command allows you to change the
-.Sq mode
-of the specified link.
-This is normally only useful in multi-link mode,
-but may also be used in uni-link mode.
-.Pp
-It is not possible to change a link that is
-.Sq direct
-or
-.Sq dedicated .
-.Pp
-Note: If you issue the command
-.Dq set mode auto ,
-and have network address translation enabled, it may be useful to
-.Dq enable iface-alias
-afterwards.
-This will allow
-.Nm
-to do the necessary address translations to enable the process that
-triggers the connection to connect once the link is up despite the
-peer assigning us a new (dynamic) IP address.
-.It set mppe Op 40|56|128|* Op stateless|stateful|*
-This option selects the encryption parameters used when negotiation
-MPPE.
-MPPE can be disabled entirely with the
-.Dq disable mppe
-command.
-If no arguments are given,
-.Nm
-will attempt to negotiate a stateful link with a 128 bit key, but
-will agree to whatever the peer requests (including no encryption
-at all).
-.Pp
-If any arguments are given,
-.Nm
-will
-.Em insist
-on using MPPE and will close the link if it's rejected by the peer.
-.Pp
-The first argument specifies the number of bits that
-.Nm
-should insist on during negotiations and the second specifies whether
-.Nm
-should insist on stateful or stateless mode.
-In stateless mode, the
-encryption dictionary is re-initialised with every packet according to
-an encryption key that is changed with every packet.
-In stateful mode,
-the encryption dictionary is re-initialised every 256 packets or after
-the loss of any data and the key is changed every 256 packets.
-Stateless mode is less efficient but is better for unreliable transport
-layers.
-.It set mrru Op Ar value
-Setting this option enables Multi-link PPP negotiations, also known as
-Multi-link Protocol or MP.
-There is no default MRRU (Maximum Reconstructed Receive Unit) value.
-If no argument is given, multi-link mode is disabled.
-.It set mru Xo
-.Op max Ns Op imum
-.Op Ar value
-.Xc
-The default MRU (Maximum Receive Unit) is 1500.
-If it is increased, the other side *may* increase its MTU.
-In theory there is no point in decreasing the MRU to below the default as the
-.Em PPP
-protocol says implementations *must* be able to accept packets of at
-least 1500 octets.
-.Pp
-If the
-.Dq maximum
-keyword is used,
-.Nm
-will refuse to negotiate a higher value.
-The maximum MRU can be set to 2048 at most.
-Setting a maximum of less than 1500 violates the
-.Em PPP
-rfc, but may sometimes be necessary.
-For example,
-.Em PPPoE
-imposes a maximum of 1492 due to hardware limitations.
-.Pp
-If no argument is given, 1500 is assumed.
-A value must be given when
-.Dq maximum
-is specified.
-.It set mtu Xo
-.Op max Ns Op imum
-.Op Ar value
-.Xc
-The default MTU is 1500.
-At negotiation time,
-.Nm
-will accept whatever MRU the peer requests (assuming it's
-not less than 296 bytes or greater than the assigned maximum).
-If the MTU is set,
-.Nm
-will not accept MRU values less than
-.Ar value .
-When negotiations are complete, the MTU is used when writing to the
-interface, even if the peer requested a higher value MRU.
-This can be useful for
-limiting your packet size (giving better bandwidth sharing at the expense
-of more header data).
-.Pp
-If the
-.Dq maximum
-keyword is used,
-.Nm
-will refuse to negotiate a higher value.
-The maximum MTU can be set to 2048 at most.
-.Pp
-If no
-.Ar value
-is given, 1500, or whatever the peer asks for is used.
-A value must be given when
-.Dq maximum
-is specified.
-.It set nbns Op Ar x.x.x.x Op Ar y.y.y.y
-This option allows the setting of the Microsoft NetBIOS name server
-values to be returned at the peers request.
-If no values are given,
-.Nm
-will reject any such requests.
-.It set openmode active|passive Op Ar delay
-By default,
-.Ar openmode
-is always
-.Ar active
-with a one second
-.Ar delay .
-That is,
-.Nm
-will always initiate LCP/IPCP/CCP negotiation one second after the line
-comes up.
-If you want to wait for the peer to initiate negotiations, you
-can use the value
-.Ar passive .
-If you want to initiate negotiations immediately or after more than one
-second, the appropriate
-.Ar delay
-may be specified here in seconds.
-.It set parity odd|even|none|mark
-This allows the line parity to be set.
-The default value is
-.Ar none .
-.It set phone Ar telno Ns Xo
-.Oo \&| Ns Ar backupnumber
-.Oc Ns ... Ns Oo : Ns Ar nextnumber
-.Oc Ns ...
-.Xc
-This allows the specification of the phone number to be used in
-place of the \\\\T string in the dial and login chat scripts.
-Multiple phone numbers may be given separated either by a pipe
-.Pq Dq \&|
-or a colon
-.Pq Dq \&: .
-.Pp
-Numbers after the pipe are only dialed if the dial or login
-script for the previous number failed.
-.Pp
-Numbers after the colon are tried sequentially, irrespective of
-the reason the line was dropped.
-.Pp
-If multiple numbers are given,
-.Nm
-will dial them according to these rules until a connection is made, retrying
-the maximum number of times specified by
-.Dq set redial
-below.
-In
-.Fl background
-mode, each number is attempted at most once.
-.It set Op proc Ns Xo
-.No title Op Ar value
-.Xc
-The current process title as displayed by
-.Xr ps 1
-is changed according to
-.Ar value .
-If
-.Ar value
-is not specified, the original process title is restored.
-All the
-word replacements done by the shell commands (see the
-.Dq bg
-command above) are done here too.
-.Pp
-Note, if USER is required in the process title, the
-.Dq set proctitle
-command must appear in
-.Pa ppp.linkup ,
-as it is not known when the commands in
-.Pa ppp.conf
-are executed.
-.It set radius Op Ar config-file
-This command enables RADIUS support (if it's compiled in).
-.Ar config-file
-refers to the radius client configuration file as described in
-.Xr radius.conf 5 .
-If PAP or CHAP are
-.Dq enable Ns No d ,
-.Nm
-behaves as a
-.Em \&N Ns No etwork
-.Em \&A Ns No ccess
-.Em \&S Ns No erver
-and uses the configured RADIUS server to authenticate rather than
-authenticating from the
-.Pa ppp.secret
-file or from the passwd database.
-.Pp
-If neither PAP or CHAP are enabled,
-.Dq set radius
-will do nothing.
-.Pp
-.Nm
-uses the following attributes from the RADIUS reply:
-.Bl -tag -width XXX -offset XXX
-.It RAD_FRAMED_IP_ADDRESS
-The peer IP address is set to the given value.
-.It RAD_FRAMED_IP_NETMASK
-The tun interface netmask is set to the given value.
-.It RAD_FRAMED_MTU
-If the given MTU is less than the peers MRU as agreed during LCP
-negotiation, *and* it is less that any configured MTU (see the
-.Dq set mru
-command), the tun interface MTU is set to the given value.
-.It RAD_FRAMED_COMPRESSION
-If the received compression type is
-.Dq 1 ,
-.Nm
-will request VJ compression during IPCP negotiations despite any
-.Dq disable vj
-configuration command.
-.It RAD_FRAMED_ROUTE
-The received string is expected to be in the format
-.Ar dest Ns Op / Ns Ar bits
-.Ar gw
-.Op Ar metrics .
-Any specified metrics are ignored.
-.Dv MYADDR
-and
-.Dv HISADDR
-are understood as valid values for
-.Ar dest
-and
-.Ar gw ,
-.Dq default
-can be used for
-.Ar dest
-to sepcify the default route, and
-.Dq 0.0.0.0
-is understood to be the same as
-.Dq default
-for
-.Ar dest
-and
-.Dv HISADDR
-for
-.Ar gw .
-.Pp
-For example, a returned value of
-.Dq 1.2.3.4/24 0.0.0.0 1 2 -1 3 400
-would result in a routing table entry to the 1.2.3.0/24 network via
-.Dv HISADDR
-and a returned value of
-.Dq 0.0.0.0 0.0.0.0
-or
-.Dq default HISADDR
-would result in a default route to
-.Dv HISADDR .
-.Pp
-All RADIUS routes are applied after any sticky routes are applied, making
-RADIUS routes override configured routes.
-This also applies for RADIUS routes that don't include the
-.Dv MYADDR
-or
-.Dv HISADDR
-keywords.
-.Pp
-.El
-Values received from the RADIUS server may be viewed using
-.Dq show bundle .
-.It set reconnect Ar timeout ntries
-Should the line drop unexpectedly (due to loss of CD or LQR
-failure), a connection will be re-established after the given
-.Ar timeout .
-The line will be re-connected at most
-.Ar ntries
-times.
-.Ar Ntries
-defaults to zero.
-A value of
-.Ar random
-for
-.Ar timeout
-will result in a variable pause, somewhere between 1 and 30 seconds.
-.It set recvpipe Op Ar value
-This sets the routing table RECVPIPE value.
-The optimum value is just over twice the MTU value.
-If
-.Ar value
-is unspecified or zero, the default kernel controlled value is used.
-.It set redial Ar secs Ns Xo
-.Oo + Ns Ar inc Ns
-.Op - Ns Ar max Ns
-.Oc Ns Op . Ns Ar next
-.Op Ar attempts
-.Xc
-.Nm
-can be instructed to attempt to redial
-.Ar attempts
-times.
-If more than one phone number is specified (see
-.Dq set phone
-above), a pause of
-.Ar next
-is taken before dialing each number.
-A pause of
-.Ar secs
-is taken before starting at the first number again.
-A literal value of
-.Dq Li random
-may be used here in place of
-.Ar secs
-and
-.Ar next ,
-causing a random delay of between 1 and 30 seconds.
-.Pp
-If
-.Ar inc
-is specified, its value is added onto
-.Ar secs
-each time
-.Nm
-tries a new number.
-.Ar secs
-will only be incremented at most
-.Ar max
-times.
-.Ar max
-defaults to 10.
-.Pp
-Note, the
-.Ar secs
-delay will be effective, even after
-.Ar attempts
-has been exceeded, so an immediate manual dial may appear to have
-done nothing.
-If an immediate dial is required, a
-.Dq !\&
-should immediately follow the
-.Dq open
-keyword.
-See the
-.Dq open
-description above for further details.
-.It set sendpipe Op Ar value
-This sets the routing table SENDPIPE value.
-The optimum value is just over twice the MTU value.
-If
-.Ar value
-is unspecified or zero, the default kernel controlled value is used.
-.It "set server|socket" Ar TcpPort Ns No \&| Ns Xo
-.Ar LocalName Ns No |none|open|closed
-.Op password Op Ar mask
-.Xc
-This command tells
-.Nm
-to listen on the given socket or
-.Sq diagnostic port
-for incoming command connections.
-.Pp
-The word
-.Dq none
-instructs
-.Nm
-to close any existing socket and clear the socket configuration.
-The word
-.Dq open
-instructs
-.Nm
-to attempt to re-open the port.
-The word
-.Dq closed
-instructs
-.Nm
-to close the open port.
-.Pp
-If you wish to specify a local domain socket,
-.Ar LocalName
-must be specified as an absolute file name, otherwise it is assumed
-to be the name or number of a TCP port.
-You may specify the octal umask to be used with a local domain socket.
-Refer to
-.Xr umask 2
-for umask details.
-Refer to
-.Xr services 5
-for details of how to translate TCP port names.
-.Pp
-You must also specify the password that must be entered by the client
-(using the
-.Dq passwd
-variable above) when connecting to this socket.
-If the password is
-specified as an empty string, no password is required for connecting clients.
-.Pp
-When specifying a local domain socket, the first
-.Dq %d
-sequence found in the socket name will be replaced with the current
-interface unit number.
-This is useful when you wish to use the same
-profile for more than one connection.
-.Pp
-In a similar manner TCP sockets may be prefixed with the
-.Dq +
-character, in which case the current interface unit number is added to
-the port number.
-.Pp
-When using
-.Nm
-with a server socket, the
-.Xr pppctl 8
-command is the preferred mechanism of communications.
-Currently,
-.Xr telnet 1
-can also be used, but link encryption may be implemented in the future, so
-.Xr telnet 1
-should be avoided.
-.Pp
-Note;
-.Dv SIGUSR1
-and
-.Dv SIGUSR2
-interact with the diagnostic socket.
-.It set speed Ar value
-This sets the speed of the serial device.
-If speed is specified as
-.Dq sync ,
-.Nm
-treats the device as a synchronous device.
-.Pp
-Certain device types will know whether they should be specified as
-synchronous or asynchronous.
-These devices will override incorrect
-settings and log a warning to this effect.
-.It set stopped Op Ar LCPseconds Op Ar CCPseconds
-If this option is set,
-.Nm
-will time out after the given FSM (Finite State Machine) has been in
-the stopped state for the given number of
-.Dq seconds .
-This option may be useful if the peer sends a terminate request,
-but never actually closes the connection despite our sending a terminate
-acknowledgement.
-This is also useful if you wish to
-.Dq set openmode passive
-and time out if the peer doesn't send a Configure Request within the
-given time.
-Use
-.Dq set log +lcp +ccp
-to make
-.Nm
-log the appropriate state transitions.
-.Pp
-The default value is zero, where
-.Nm
-doesn't time out in the stopped state.
-.Pp
-This value should not be set to less than the openmode delay (see
-.Dq set openmode
-above).
-.It set timeout Ar idleseconds Op Ar mintimeout
-This command allows the setting of the idle timer.
-Refer to the section titled
-.Sx SETTING THE IDLE TIMER
-for further details.
-.Pp
-If
-.Ar mintimeout
-is specified,
-.Nm
-will never idle out before the link has been up for at least that number
-of seconds.
-.It set urgent Xo
-.Op tcp|udp|none
-.Oo Op +|- Ns
-.Ar port
-.Oc No ...
-.Xc
-This command controls the ports that
-.Nm
-prioritizes when transmitting data.
-The default priority TCP ports
-are ports 21 (ftp control), 22 (ssh), 23 (telnet), 513 (login), 514 (shell),
-543 (klogin) and 544 (kshell).
-There are no priority UDP ports by default.
-See
-.Xr services 5
-for details.
-.Pp
-If neither
-.Dq tcp
-or
-.Dq udp
-are specified,
-.Dq tcp
-is assumed.
-.Pp
-If no
-.Ar port Ns No s
-are given, the priority port lists are cleared (although if
-.Dq tcp
-or
-.Dq udp
-is specified, only that list is cleared).
-If the first
-.Ar port
-argument is prefixed with a plus
-.Pq Dq \&+
-or a minus
-.Pq Dq \&- ,
-the current list is adjusted, otherwise the list is reassigned.
-.Ar port Ns No s
-prefixed with a plus or not prefixed at all are added to the list and
-.Ar port Ns No s
-prefixed with a minus are removed from the list.
-.Pp
-If
-.Dq none
-is specified, all priority port lists are disabled and even
-.Dv IPTOS_LOWDELAY
-packets are not prioritised.
-.It set vj slotcomp on|off
-This command tells
-.Nm
-whether it should attempt to negotiate VJ slot compression.
-By default, slot compression is turned
-.Ar on .
-.It set vj slots Ar nslots
-This command sets the initial number of slots that
-.Nm
-will try to negotiate with the peer when VJ compression is enabled (see the
-.Sq enable
-command above).
-It defaults to a value of 16.
-.Ar Nslots
-must be between
-.Ar 4
-and
-.Ar 16
-inclusive.
-.El
-.Pp
-.It shell|! Op Ar command
-If
-.Ar command
-is not specified a shell is invoked according to the
-.Dv SHELL
-environment variable.
-Otherwise, the given
-.Ar command
-is executed.
-Word replacement is done in the same way as for the
-.Dq !bg
-command as described above.
-.Pp
-Use of the ! character
-requires a following space as with any of the other commands.
-You should note that this command is executed in the foreground;
-.Nm
-will not continue running until this process has exited.
-Use the
-.Dv bg
-command if you wish processing to happen in the background.
-.It show Ar var
-This command allows the user to examine the following:
-.Bl -tag -width 2n
-.It show bundle
-Show the current bundle settings.
-.It show ccp
-Show the current CCP compression statistics.
-.It show compress
-Show the current VJ compression statistics.
-.It show escape
-Show the current escape characters.
-.It show filter Op Ar name
-List the current rules for the given filter.
-If
-.Ar name
-is not specified, all filters are shown.
-.It show hdlc
-Show the current HDLC statistics.
-.It show help|?
-Give a summary of available show commands.
-.It show iface
-Show the current interface information
-(the same as
-.Dq iface show ) .
-.It show ipcp
-Show the current IPCP statistics.
-.It show layers
-Show the protocol layers currently in use.
-.It show lcp
-Show the current LCP statistics.
-.It show Op data Ns Xo
-.No link
-.Xc
-Show high level link information.
-.It show links
-Show a list of available logical links.
-.It show log
-Show the current log values.
-.It show mem
-Show current memory statistics.
-.It show physical
-Show low level link information.
-.It show mp
-Show Multi-link information.
-.It show proto
-Show current protocol totals.
-.It show route
-Show the current routing tables.
-.It show stopped
-Show the current stopped timeouts.
-.It show timer
-Show the active alarm timers.
-.It show version
-Show the current version number of
-.Nm .
-.El
-.Pp
-.It term
-Go into terminal mode.
-Characters typed at the keyboard are sent to the device.
-Characters read from the device are displayed on the screen.
-When a remote
-.Em PPP
-peer is detected,
-.Nm
-automatically enables Packet Mode and goes back into command mode.
-.El
-.Sh MORE DETAILS
-.Bl -bullet
-.It
-Read the example configuration files.
-They are a good source of information.
-.It
-Use
-.Dq help ,
-.Dq nat \&? ,
-.Dq enable \&? ,
-.Dq set ?\&
-and
-.Dq show ?\&
-to get online information about what's available.
-.It
-The following URLs contain useful information:
-.Bl -bullet -compact
-.It
-http://www.FreeBSD.org/FAQ/userppp.html
-.It
-http://www.FreeBSD.org/handbook/userppp.html
-.El
-.Pp
-.El
-.Sh FILES
-.Nm
-refers to four files:
-.Pa ppp.conf ,
-.Pa ppp.linkup ,
-.Pa ppp.linkdown
-and
-.Pa ppp.secret .
-These files are placed in the
-.Pa /etc/ppp
-directory.
-.Bl -tag -width 2n
-.It Pa /etc/ppp/ppp.conf
-System default configuration file.
-.It Pa /etc/ppp/ppp.secret
-An authorisation file for each system.
-.It Pa /etc/ppp/ppp.linkup
-A file to check when
-.Nm
-establishes a network level connection.
-.It Pa /etc/ppp/ppp.linkdown
-A file to check when
-.Nm
-closes a network level connection.
-.It Pa /var/log/ppp.log
-Logging and debugging information file.
-Note, this name is specified in
-.Pa /etc/syslogd.conf .
-See
-.Xr syslog.conf 5
-for further details.
-.It Pa /var/spool/lock/LCK..*
-tty port locking file.
-Refer to
-.Xr uucplock 3
-for further details.
-.It Pa /var/run/tunN.pid
-The process id (pid) of the
-.Nm
-program connected to the tunN device, where
-.Sq N
-is the number of the device.
-.It Pa /var/run/ttyXX.if
-The tun interface used by this port.
-Again, this file is only created in
-.Fl background ,
-.Fl auto
-and
-.Fl ddial
-modes.
-.It Pa /etc/services
-Get port number if port number is using service name.
-.It Pa /var/run/ppp-authname-class-value
-In multi-link mode, local domain sockets are created using the peer
-authentication name
-.Pq Sq authname ,
-the peer endpoint discriminator class
-.Pq Sq class
-and the peer endpoint discriminator value
-.Pq Sq value .
-As the endpoint discriminator value may be a binary value, it is turned
-to HEX to determine the actual file name.
-.Pp
-This socket is used to pass links between different instances of
-.Nm .
-.El
-.Sh SEE ALSO
-.Xr at 1 ,
-.Xr ftp 1 ,
-.Xr gzip 1 ,
-.Xr hostname 1 ,
-.Xr login 1 ,
-.Xr tcpdump 1 ,
-.Xr telnet 1 ,
-.Xr kldload 2 ,
-.Xr libalias 3 ,
-.Xr syslog 3 ,
-.Xr uucplock 3 ,
-.Xr netgraph 4 ,
-.Xr ng_pppoe 4 ,
-.Xr crontab 5 ,
-.Xr group 5 ,
-.Xr passwd 5 ,
-.Xr protocols 5 ,
-.Xr radius.conf 5 ,
-.Xr resolv.conf 5 ,
-.Xr syslog.conf 5 ,
-.Xr adduser 8 ,
-.Xr chat 8 ,
-.Xr getty 8 ,
-.Xr inetd 8 ,
-.Xr init 8 ,
-.Xr isdn 8 ,
-.Xr named 8 ,
-.Xr ping 8 ,
-.Xr pppctl 8 ,
-.Xr pppd 8 ,
-.Xr pppoe 8 ,
-.Xr route 8 ,
-.Xr sshd 8 ,
-.Xr syslogd 8 ,
-.Xr traceroute 8 ,
-.Xr vipw 8
-.Sh HISTORY
-This program was originally written by
-.An Toshiharu OHNO Aq tony-o@iij.ad.jp ,
-and was submitted to
-.Fx 2.0.5
-by
-.An Atsushi Murai Aq amurai@spec.co.jp .
-.Pp
-It was substantially modified during 1997 by
-.An Brian Somers Aq brian@Awfulhak.org ,
-and was ported to
-.Ox
-in November that year
-(just after the 2.2 release).
-.Pp
-Most of the code was rewritten by
-.An Brian Somers
-in early 1998 when multi-link ppp support was added.
diff --git a/usr.sbin/ppp/ppp.8.m4 b/usr.sbin/ppp/ppp.8.m4
index 29e7681..e656c3b 100644
--- a/usr.sbin/ppp/ppp.8.m4
+++ b/usr.sbin/ppp/ppp.8.m4
@@ -1,3 +1,5 @@
+changequote({,})dnl
+changecom(,)dnl
 .\"
 .\" Copyright (c) 2001 Brian Somers <brian@Awfulhak.org>
 .\" All rights reserved.
@@ -63,9 +65,10 @@ This allows
 .Nm
 to act as a NAT or masquerading engine for all machines on an internal
 LAN.
-Refer to
+ifdef({LOCALNAT},{},{Refer to
 .Xr libalias 3
 for details.
+})dnl
 .Pp
 The
 .Fl quiet
@@ -205,7 +208,7 @@ When you are connected to the remote peer and it starts to talk
 detects it and switches to packet mode automatically.
 Once you have
 determined the proper sequence for connecting with the remote host, you
-can write a chat script to define the necessary dialing and login
+can write a chat script to {define} the necessary dialing and login
 procedure for later convenience.
 .It Supports on-demand dialup capability.
 By using
@@ -287,13 +290,14 @@ An extension to PAP and CHAP,
 allows authentication information to be stored in a central or
 distributed database along with various per-user framed connection
 characteristics.
-If
-.Pa libradius
+ifdef({LOCALRAD},{},{If
+.Xr libradius 3
 is available at compile time,
 .Nm
 will use it to make
 .Em RADIUS
 requests when configured to do so.
+})dnl
 .It Supports Proxy Arp.
 .Nm
 can be configured to make one or more proxy arp entries on behalf of
@@ -301,13 +305,13 @@ the peer.
 This allows routing from the peer to the LAN without
 configuring each machine on that LAN.
 .It Supports packet filtering.
-User can define four kinds of filters: the
+User can {define} four kinds of filters: the
 .Em in
 filter for incoming packets, the
 .Em out
 filter for outgoing packets, the
 .Em dial
-filter to define a dialing trigger packet and the
+filter to {define} a dialing trigger packet and the
 .Em alive
 filter for keeping a connection alive with the trigger packet.
 .It Tunnel driver supports bpf.
@@ -425,7 +429,7 @@ When you first run
 you may need to deal with some initial configuration details.
 .Bl -bullet
 .It
-Your kernel must include a tunnel device (the GENERIC kernel includes
+Your kernel must {include} a tunnel device (the GENERIC kernel includes
 one by default).
 If it doesn't, or if you require more than one tun
 interface, you'll need to rebuild your kernel with the following line in
@@ -779,10 +783,10 @@ character is treated as a comment line.
 Leading whitespace are ignored when identifying comment lines.
 .It
 An inclusion is a line beginning with the word
-.Sq !include .
-It must have one argument - the file to include.
+.Sq {!include} .
+It must have one argument - the file to {include}.
 You may wish to
-.Dq !include ~/.ppp.conf
+.Dq {!include} ~/.ppp.conf
 for compatibility with older versions of
 .Nm .
 .It
@@ -948,7 +952,7 @@ You must also specify the destination label in
 to use.
 It must contain the
 .Dq set ifaddr
-command to define the remote peers IP address.
+command to {define} the remote peers IP address.
 (refer to
 .Pa /usr/share/examples/ppp/ppp.conf.sample )
 .Bd -literal -offset indent
@@ -2167,7 +2171,7 @@ In general, the serial speed should be about four times the modem speed.
 .It
 Use the
 .Dq set ifaddr
-command to define the IP address.
+command to {define} the IP address.
 .Bl -bullet
 .It
 If you know what IP address your provider uses, then use it as the remote
@@ -2189,7 +2193,7 @@ specify third and forth arguments of
 This will force your ISP to assign a number.
 (The third argument will
 be ignored as it is less restrictive than the default mask for your
-.Sq src_addr .
+.Sq src_addr ) .
 .El
 .Pp
 An example for a connection where you don't know your IP number or your
@@ -3119,9 +3123,10 @@ The option can only be enabled if network address translation is enabled
 .Pp
 With this option enabled,
 .Nm
-will pass traffic for old interface addresses through the NAT engine
+will pass traffic for old interface addresses through the NAT 
+ifdef({LOCALNAT},{engine,},{engine
 (see
-.Xr libalias 3 ) ,
+.Xr libalias 3 ) ,})
 resulting in the ability (in
 .Fl auto
 mode) to properly connect the process that caused the PPP link to
@@ -3310,16 +3315,18 @@ you wish to map to specific machines behind your gateway.
 .It nat deny_incoming yes|no
 If set to yes, this command will refuse all incoming packets where an
 aliasing link doesn't already exist.
-Refer to the
+ifdef({LOCALNAT},{},{Refer to the
 .Sx CONCEPTUAL BACKGROUND
 section of
 .Xr libalias 3
 for a description of what an
 .Dq aliasing link
 is.
+})dnl
 .Pp
-It should be noted under what circumstances an aliasing link is created by
-.Xr libalias 3 .
+It should be noted under what circumstances an aliasing link is 
+ifdef({LOCALNAT},{created.},{created by
+.Xr libalias 3 .})
 It may be necessary to further protect your network from outside
 connections using the
 .Dq set filter
@@ -3404,11 +3411,12 @@ for example:
 This command tells
 .Nm
 to proxy certain connections, redirecting them to a given server.
-Refer to the description of
+ifdef({LOCALNAT},{},{Refer to the description of
 .Fn PacketAliasProxyRule
 in
 .Xr libalias 3
 for details of the available commands.
+})dnl
 .It nat punch_fw Op Ar base count
 This command tells
 .Nm
@@ -3436,8 +3444,9 @@ if you want to support protocols such as RPC and LPD which require
 connections to come from a well known port.
 .It nat target Op Ar address
 Set the given target address or clear it if no address is given.
-The target address is used by libalias to specify how to NAT incoming
-packets by default.
+The target address is used
+ifdef({LOCALNAT},{},{by libalias })dnl
+to specify how to NAT incoming packets by default.
 If a target address is not set or if
 .Dq default
 is given, packets are not altered and are allowed to route to the internal
@@ -3445,7 +3454,10 @@ network.
 .Pp
 The target address may be set to
 .Dq MYADDR ,
-in which case libalias will redirect all packets to the interface address.
+in which case 
+ifdef({LOCALNAT},{all packets will be redirected},
+{libalias will redirect all packets})
+to the interface address.
 .It nat use_sockets yes|no
 When enabled, this option tells the network address translation engine to
 create a socket so that it can guarantee a correct incoming ftp data or
@@ -4141,7 +4153,7 @@ In server mode,
 will accept any of the given protocols - but the client
 .Em must
 request one of them.
-If you wish callback to be optional, you must include
+If you wish callback to be optional, you must {include}
 .Ar none
 as an option.
 .Pp
@@ -5222,7 +5234,7 @@ would result in a default route to
 .Pp
 All RADIUS routes are applied after any sticky routes are applied, making
 RADIUS routes override configured routes.
-This also applies for RADIUS routes that don't include the
+This also applies for RADIUS routes that don't {include} the
 .Dv MYADDR
 or
 .Dv HISADDR
@@ -5690,7 +5702,10 @@ This socket is used to pass links between different instances of
 .Xr tcpdump 1 ,
 .Xr telnet 1 ,
 .Xr kldload 2 ,
-.Xr libalias 3 ,
+ifdef({LOCALNAT},{},{.Xr libalias 3 ,
+})dnl
+ifdef({LOCALRAD},{},{.Xr libradius 3 ,
+})dnl
 .Xr syslog 3 ,
 .Xr uucplock 3 ,
 .Xr netgraph 4 ,