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PPP(8)			  BSD System Manager's Manual			PPP(8)

NAME
     ppp -- Point to Point Protocol (a.k.a. user-ppp)

SYNOPSIS
     ppp [-mode] [-nat]	[-quiet] [-unitN] [system ...]

DESCRIPTION
     This is a user process PPP	software package.  Normally, PPP is imple-
     mented as a part of the kernel (e.g., as managed by pppd(8)) and it's
     thus somewhat hard	to debug and/or	modify its behaviour.  However,	in
     this implementation PPP is	done as	a user process with the	help of	the
     tunnel device driver (tun).

     The -nat flag does	the equivalent of a "nat enable	yes", enabling ppp's
     network address translation features.  This allows	ppp to act as a	NAT or
     masquerading engine for all machines on an	internal LAN.  Refer to
     libalias(3) for details on	the technical side of the NAT engine.  Refer
     to	the NETWORK ADDRESS TRANSLATION	(PACKET	ALIASING) section of this man-
     ual page for details on how to configure NAT in ppp.

     The -quiet	flag tells ppp to be silent at startup rather than displaying
     the mode and interface to standard	output.

     The -unit flag tells ppp to only attempt to open /dev/tunN.  Normally,
     ppp will start with a value of 0 for N, and keep trying to	open a tunnel
     device by incrementing the	value of 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.

     The following modes are understood	by ppp:

	-auto
	     ppp opens the tun interface, configures it	then goes into the
	     background.  The link isn't brought up until outgoing data	is de-
	     tected on the tun interface at which point	ppp attempts to	bring
	     up	the link.  Packets received (including the first one) while
	     ppp is trying to bring the	link up	will remain queued for a de-
	     fault of 2	minutes.  See the "set choked" command below.

	     In	-auto mode, at least one "system" must be given	on the command
	     line (see below) and a "set ifaddr" must be done in the system
	     profile that specifies a peer IP address to use when configuring
	     the interface.  Something like "10.0.0.1/0" is usually appropri-
	     ate.  See the "pmdemand" system in
	     /usr/share/examples/ppp/ppp.conf.sample for an example.

	-background
	     Here, ppp attempts	to establish a connection with the peer	imme-
	     diately.  If it succeeds, ppp goes	into the background and	the
	     parent process returns an exit code of 0.	If it fails, ppp exits
	     with a non-zero result.

	-foreground
	     In	foreground mode, ppp 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	con-
	     trol ppp's	invocation from	another	process.

	-direct
	     This is used for communicating over an already established	con-
	     nection, usually when receiving incoming connections accepted by
	     getty(8).	ppp ignores the	"set device" line and uses descriptor
	     0 as the link.  ppp will also ignore any configured chat scripts
	     unless the	"force-scripts"	option has been	enabled.

	     If	callback is configured,	ppp will use the "set device" informa-
	     tion when dialing back.

	-dedicated
	     This option is designed for machines connected with a dedicated
	     wire.  ppp	will always keep the device open and will ignore any
	     configured	chat scripts unless the	"force-scripts"	option has
	     been enabled.

	-ddial
	     This mode is equivalent to	-auto mode except that ppp will	bring
	     the link back up any time it's dropped for	any reason.

	-interactive
	     This is a no-op, and gives	the same behaviour as if none of the
	     above modes have been specified.  ppp loads any sections speci-
	     fied on the command line then provides an interactive prompt.

     One or more configuration entries or systems (as specified	in
     /etc/ppp/ppp.conf)	may also be specified on the command line.  ppp	will
     read the "default"	system from /etc/ppp/ppp.conf at startup, followed by
     each of the systems specified on the command line.

Major Features
     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	func-
     tions can also be optionally password protected for security.

     Supports both manual and automatic	dialing.  Interactive mode has a
     "term" command which enables you to talk to the device directly.  When
     you are connected to the remote peer and it starts	to talk	PPP, ppp de-
     tects it and switches to packet mode automatically.  Once you have	deter-
     mined 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.

     Supports on-demand	dialup capability.  By using -auto mode, ppp will act
     as	a daemon and wait for a	packet to be sent over the PPP link.  When
     this happens, the daemon automatically dials and establishes the connec-
     tion.  In almost the same manner -ddial mode (direct-dial mode) also au-
     tomatically 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 -dedicated mode is also available.
     This mode is targeted at a	dedicated link between two machines.  ppp will
     never voluntarily quit from dedicated mode	- you must send	it the "quit
     all" command via its diagnostic socket.  A	SIGHUP will force an LCP rene-
     gotiation,	and a SIGTERM will force it to exit.

     Supports client callback.	ppp can	use either the standard	LCP callback
     protocol or the Microsoft CallBack	Control	Protocol (ftp://ftp.micro-
     soft.com/developr/rfc/cbcp.txt).

     Supports NAT or packet aliasing.  Packet aliasing (a.k.a. IP masquerad-
     ing) allows computers on a	private, unregistered network to access	the
     Internet.	The 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.

     Supports background PPP connections.  In background mode, if ppp success-
     fully 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 estab-
     lished.

     Supports server-side PPP connections.  In direct mode, ppp	acts as	server
     which accepts incoming PPP	connections on stdin/stdout.

     Supports PAP and CHAP (rfc	1994, 2433 and 2759) authentication.  With PAP
     or	CHAP, it is possible to	skip the Unix style login(1) procedure,	and
     use the PPP protocol for authentication instead.  If the peer requests
     Microsoft CHAP authentication and ppp is compiled with DES	support, an
     appropriate MD4/DES response will be made.

     Supports RADIUS (rfc 2138 & 2548) authentication.	An extension to	PAP
     and CHAP, Remote Access Dial In User Service allows authentication	infor-
     mation to be stored in a central or distributed database along with vari-
     ous per-user framed connection characteristics.  If libradius(3) is
     available at compile time,	ppp will use it	to make	RADIUS requests	when
     configured	to do so.

     Supports Proxy Arp.  ppp 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.

     Supports packet filtering.	 User can define four kinds of filters:	the in
     filter for	incoming packets, the out filter for outgoing packets, the
     dial filter to define a dialing trigger packet and	the alive filter for
     keeping a connection alive	with the trigger packet.

     Tunnel driver supports bpf.  The user can use tcpdump(1) to check the
     packet flow over the PPP link.

     Supports PPP over TCP and PPP over	UDP.  If a device name is specified as
     host:port[/tcp|udp], ppp will open	a TCP or UDP connection	for transport-
     ing data rather than using	a conventional serial device.  UDP connections
     force ppp into synchronous	mode.

     Supports PPP over ISDN.  If ppp is	given a	raw B-channel i4b device to
     open as a link, it's able to talk to the isdnd(8) daemon to establish an
     ISDN connection.

     Supports PPP over Ethernet	(rfc 2516).  If	ppp is given a device specifi-
     cation of the format PPPoE:iface[:provider] and if	netgraph(4) is avail-
     able, ppp will attempt talk PPP over Ethernet to provider using the iface
     network interface.

     On	systems	that do	not support netgraph(4), an external program such as
     pppoed(8) may be used.

     Supports IETF draft Predictor-1 (rfc 1978)	and DEFLATE (rfc 1979)
     compression.  ppp 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-compres-
     sion, Predictor-1 and DEFLATE compression pre-compresses all network
     traffic flowing through the link, thus reducing overheads to a minimum.

     Supports Microsoft's IPCP extensions (rfc 1877).  Name Server Addresses
     and NetBIOS Name Server Addresses can be negotiated with clients using
     the Microsoft PPP stack (i.e., Win95, WinNT)

     Supports Multi-link PPP (rfc 1990)	 It is possible	to configure ppp to
     open more than one	physical connection to the peer, combining the band-
     width of all links	for better throughput.

     Supports MPPE (draft-ietf-pppext-mppe)  MPPE is Microsoft Point to	Point
     Encryption	scheme.	 It is possible	to configure ppp to participate	in Mi-
     crosoft's Windows VPN.  For now, ppp can only get encryption keys from
     CHAP 81 authentication.  ppp must be compiled with	DES for	MPPE to	oper-
     ate.

     Supports IPV6CP (rfc 2023).  An IPv6 connection can be made in addition
     to	or instead of the normal IPv4 connection.

PERMISSIONS
     ppp is installed as user root and group network, with permissions 04554.
     By	default, ppp will not run if the invoking user id is not zero.	This
     may be overridden by using	the "allow users" command in
     /etc/ppp/ppp.conf.	 When running as a normal user,	ppp 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 in-
     voked ppp.	 Refer to the `ID0' logging facility if	you're interested in
     what exactly is done as user id zero.

GETTING	STARTED
     When you first run	ppp you	may need to deal with some initial configura-
     tion details.

     +o	 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:

	       pseudo-device tun N

	 where N is the	maximum	number of PPP connections you wish to support.

     +o	 Check your /dev directory for the tunnel device entries /dev/tunN,
	 where `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	N.

     +o	 Make sure that	your system has	a group	named "network"	in the
	 /etc/group file and that the group contains the names of all users
	 expected to use ppp.  Refer to	the group(5) manual page for details.
	 Each of these users must also be given	access using the "allow	users"
	 command in /etc/ppp/ppp.conf.

     +o	 Create	a log file.  ppp uses syslog(3)	to log information.  A common
	 log file name is /var/log/ppp.log.  To	make output go to this file,
	 put the following lines in the	/etc/syslog.conf file:

	       !ppp
	       *.*<TAB>/var/log/ppp.log

	 It is possible	to have	more than one PPP log file by creating a link
	 to the	ppp executable:

	       # cd /usr/sbin
	       # ln ppp	ppp0

	 and using

	       !ppp0
	       *.*<TAB>/var/log/ppp0.log

	 in /etc/syslog.conf.  Don't forget to send a HUP signal to syslogd(8)
	 after altering	/etc/syslog.conf.

     +o	 Although not strictly relevant	to ppp's operation, you	should config-
	 ure your resolver so that it works correctly.	This can be done by
	 configuring a local DNS (using	named(8)) or by	adding the correct
	 `nameserver' lines to the file	/etc/resolv.conf.  Refer to the
	 resolv.conf(5)	manual page for	details.

	 Alternatively,	if the peer supports it, ppp can be configured to ask
	 the peer for the nameserver address(es) and to	update
	 /etc/resolv.conf automatically.  Refer	to the "enable dns" and
	 "resolv" commands below for details.

MANUAL DIALING
     In	the following examples,	we assume that your machine name is awfulhak.
     when you invoke ppp (see PERMISSIONS above) with no arguments, you	are
     presented with a prompt:

	   ppp ON awfulhak>

     The `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 "passwd"
     command.  This only ever happens if you connect to	a running version of
     ppp and have not authenticated yourself using the correct password.

     You can start by specifying the device name and speed:

	   ppp ON awfulhak> set	device /dev/cuaa0
	   ppp ON awfulhak> set	speed 38400

     Normally, hardware	flow control (CTS/RTS) is used.	 However, under	cer-
     tain circumstances	(as may	happen when you	are connected directly to cer-
     tain PPP-capable terminal servers), this may result in ppp	hanging	as
     soon as it	tries to write data to your communications link	as it is wait-
     ing 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 "set ctsrts off".	 If you	need to	do this, check the
     "set accmap" description below too	- you'll probably need to "set accmap
     000a0000".

     Usually, parity is	set to "none", and this	is ppp'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 ppp is) use much more	reliable checking mechanisms.  Parity
     has a relatively huge overhead (a 12.5% increase in traffic) and as a re-
     sult, it is always	disabled (set to "none") when PPP is opened.  However,
     some ISPs (Internet Service Providers) may	use specific parity settings
     at	connection time	(before	PPP is opened).	 Notably, Compuserve insist on
     even parity when logging in:

	   ppp ON awfulhak> set	parity even

     You can now see what your current device settings look like:

	   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>

     The term command can now be used to talk directly to the device:

	   ppp ON awfulhak> term
	   at
	   OK
	   atdt123456
	   CONNECT
	   login: myispusername
	   Password: myisppassword
	   Protocol: ppp

     When the peer starts to talk in PPP, ppp detects this automatically and
     returns to	command	mode.

	   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

     If	it does	not, it's probable that	the peer is waiting for	your end to
     start negotiating.	 To force ppp to start sending PPP configuration pack-
     ets to the	peer, use the "~p" command to drop out of terminal mode	and
     enter packet mode.

     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:

	   ~.
	   ppp ON awfulhak> set	authname myispusername
	   ppp ON awfulhak> set	authkey	myisppassword
	   ppp ON awfulhak> term
	   at
	   OK
	   atdt123456
	   CONNECT

     You may need to tell ppp to initiate negotiations with the	peer here too:

	   ~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

     You are now connected!  Note that `PPP' in	the prompt has changed to cap-
     ital 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 ppp couldn't
     successfully negotiate with the peer.  A good first step for trou-
     bleshooting at this point would be	to

	   ppp ON awfulhak> set	log local phase	lcp ipcp

     and try again.  Refer to the "set log" command description	below for fur-
     ther 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.

     When the link is established, the show command can	be used	to see how
     things are	going:

	   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 ipv6cp
	   * IPV6CP (IPv6) 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 *

     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 PPP link), enter the following	command:

	   PPP ON awfulhak> add	default	HISADDR

     The string	`HISADDR' represents the IP address of the connected peer.  If
     the "add" command fails due to an existing	route, you can overwrite the
     existing route using:

	   PPP ON awfulhak> add! default HISADDR

     This command can also be executed before actually making the connection.
     If	a new IP address is negotiated at connection time, ppp will update
     your default route	accordingly.

     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 ppp into the	background using your standard
     shell suspend and background commands (usually "^Z" followed by "bg").

     Refer to the PPP COMMAND LIST section for details on all available	com-
     mands.

AUTOMATIC DIALING
     To	use automatic dialing, you must	prepare	some Dial and Login chat
     scripts.  See the example definitions in
     /usr/share/examples/ppp/ppp.conf.sample (the format of /etc/ppp/ppp.conf
     is	pretty simple).	 Each line contains one	comment, inclusion, label or
     command:

     +o	 A line	starting with a	("#") character	is treated as a	comment	line.
	 Leading whitespace are	ignored	when identifying comment lines.

     +o	 An inclusion is a line	beginning with the word	`!include'.  It	must
	 have one argument - the file to include.  You may wish	to "!include
	 ~/.ppp.conf" for compatibility	with older versions of ppp.

     +o	 A label name starts in	the first column and is	followed by a colon
	 (":").

     +o	 A command line	must contain a space or	tab in the first column.

     +o	 A string starting with	the "$"	character is substituted with the
	 value of the environment variable by the same name.  Likewise,	a
	 string	starting with the "~" character	is substituted with the	full
	 path to the home directory of the user	account	by the same name, and
	 the "~" character by itself is	substituted with the full path to the
	 home directory	of the current user.  If you want to include a literal
	 "$" or	"~" character in a command or argument,	enclose	them in	double
	 quotes, e.g.,

	       set password "pa$ss~word"

     The /etc/ppp/ppp.conf file	should consist of at least a "default" sec-
     tion.  This section is always executed.  It should	also contain one or
     more sections, named according to their purpose, for example, "MyISP"
     would represent your ISP, and "ppp-in" would represent an incoming	ppp
     configuration.  You can now specify the destination label name when you
     invoke ppp.  Commands associated with the "default" label are executed,
     followed by those associated with the destination label provided.	When
     ppp is started with no arguments, the "default" section is	still exe-
     cuted.  The load command can be used to manually load a section from the
     /etc/ppp/ppp.conf file:

	   ppp ON awfulhak> load MyISP

     Note, no action is	taken by ppp after a section is	loaded,	whether	it's
     the result	of passing a label on the command line or using	the "load"
     command.  Only the	commands specified for that label in the configuration
     file are executed.	 However, when invoking	ppp with the -background,
     -ddial, or	-dedicated switches, the link mode tells ppp to	establish a
     connection.  Refer	to the "set mode" command below	for further details.

     Once the connection is made, the `ppp' portion of the prompt will change
     to	`PPP':

	   # ppp MyISP
	   ...
	   ppp ON awfulhak> dial
	   Ppp ON awfulhak>
	   PPp ON awfulhak>
	   PPP ON awfulhak>

     The Ppp prompt indicates that ppp has entered the authentication phase.
     The PPp prompt indicates that ppp has entered the network phase.  The PPP
     prompt indicates that ppp has successfully	negotiated a network layer
     protocol and is in	a usable state.

     If	the /etc/ppp/ppp.linkup	file is	available, its contents	are executed
     when the PPP connection is	established.  See the provided "pmdemand" ex-
     ample in /usr/share/examples/ppp/ppp.conf.sample which runs a script in
     the background after the connection is established	(refer to the "shell"
     and "bg" commands below for a description of possible substitution
     strings).	Similarly, when	a connection is	closed,	the contents of	the
     /etc/ppp/ppp.linkdown file	are executed.  Both of these files have	the
     same format as /etc/ppp/ppp.conf.

     In	previous versions of ppp, it was necessary to re-add routes such as
     the default route in the ppp.linkup file.	ppp supports `sticky routes',
     where all routes that contain the HISADDR,	MYADDR,	HISADDR6 or MYADDR6
     literals will automatically be updated when the values of these variables
     change.

BACKGROUND DIALING
     If	you want to establish a	connection using ppp non-interactively (such
     as	from a crontab(5) entry	or an at(1) job) you should use	the
     -background option.  When -background is specified, ppp attempts to es-
     tablish the connection immediately.  If multiple phone numbers are	speci-
     fied, each	phone number will be tried once.  If the attempt fails,	ppp
     exits immediately with a non-zero exit code.  If it succeeds, then	ppp
     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 TERM signal.

DIAL ON	DEMAND
     Demand dialing is enabled with the	-auto or -ddial	options.  You must
     also specify the destination label	in /etc/ppp/ppp.conf to	use.  It must
     contain the "set ifaddr" command to define	the remote peers IP address.
     (refer to /usr/share/examples/ppp/ppp.conf.sample)

	   # ppp -auto pmdemand

     When -auto	or -ddial is specified,	ppp runs as a daemon but you can still
     configure or examine its configuration by using the "set server" command
     in	/etc/ppp/ppp.conf, (for	example, "set server +3000 mypasswd") and con-
     necting to	the diagnostic port as follows:

	   # pppctl 3000   (assuming tun0)
	   Password:
	   PPP ON awfulhak> show who
	   tcp (127.0.0.1:1028)	*

     The "show who" command lists users	that are currently connected to	ppp
     itself.  If the diagnostic	socket is closed or changed to a different
     socket, all connections are immediately dropped.

     In	-auto mode, when an outgoing packet is detected, ppp will perform the
     dialing action (chat script) and try to connect with the peer.  In	-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 "set redial" command:

     set redial	secs[+inc[-max]][.next]	[attempts]

     secs      is the number of	seconds	to wait	before attempting to connect
	       again.  If the argument is the literal string `random', the de-
	       lay period is a random value between 1 and 30 seconds inclu-
	       sive.
     inc       is the number of	seconds	that secs should be incremented	each
	       time a new dial attempt is made.	 The timeout reverts to	secs
	       only after a successful connection is established.  The default
	       value for inc is	zero.
     max       is the maximum number of	times ppp should increment secs.  The
	       default value for max is	10.
     next      is the number of	seconds	to wait	before attempting to dial the
	       next number in a	list of	numbers	(see the "set phone" command).
	       The default is 3	seconds.  Again, if the	argument is the	lit-
	       eral string `random', the delay period is a random value	be-
	       tween 1 and 30 seconds.
     attempts  is the maximum number of	times to try to	connect	for each out-
	       going packet that triggers a dial.  The previous	value is un-
	       changed if this parameter is omitted.  If a value of zero is
	       specified for attempts, ppp will	keep trying until a connection
	       is made.

     So, for example:

	   set redial 10.3 4

     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).

     Alternatively,

	   set redial 10+10-5.3	20

     tells ppp to attempt to connect 20	times.	After the first	attempt, ppp
     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 ppp	connects, dis-
     connects and fails	to connect again, the timeout starts again at 10 sec-
     onds.

     Modifying the dial	delay is very useful when running ppp in -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 reli-
     able, and carrier may be lost at inappropriate times.  It is possible to
     have ppp redial should carrier be unexpectedly lost during	a session.

	   set reconnect timeout ntries

     This command tells	ppp to re-establish the	connection ntries times	on
     loss of carrier with a pause of timeout seconds before each try.  For ex-
     ample,

	   set reconnect 3 5

     tells ppp that on an unexpected loss of carrier, it should	wait 3 seconds
     before attempting to reconnect.  This may happen up to 5 times before ppp
     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 consti-
     tutes a loss of carrier and will trigger a	reconnect.  If the -background
     flag is specified,	all phone numbers are dialed at	most once until	a con-
     nection is	made.  The next	number redial period specified with the	"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

	   PPP ON awfulhak> close
	   ppp ON awfulhak> quit all

     A simple "quit" command will terminate the	pppctl(8) or telnet(1) connec-
     tion but not the ppp program itself.  You must use	"quit all" to termi-
     nate ppp as well.

RECEIVING INCOMING PPP CONNECTIONS (Method 1)
     To	handle an incoming PPP connection request, follow these	steps:

     1.	  Make sure the	modem and (optionally) /etc/rc.serial is configured
	  correctly.
	  +o   Use Hardware Handshake (CTS/RTS) for flow	control.
	  +o   Modem should be set to NO	echo back (ATE0) and NO	results	string
	      (ATQ1).

     2.	  Edit /etc/ttys to enable a getty(8) on the port where	the modem is
	  attached.  For example:

		ttyd1 "/usr/libexec/getty std.38400" dialup on secure

	  Don't	forget to send a HUP signal to the init(8) process to start
	  the getty(8):

		# kill -HUP 1

	  It is	usually	also necessary to train	your modem to the same DTR
	  speed	as the getty:

		# 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

     3.	  Create a /usr/local/bin/ppplogin file	with the following contents:

		#! /bin/sh
		exec /usr/sbin/ppp -direct incoming

	  Direct mode (-direct)	lets ppp work with stdin and stdout.  You can
	  also use pppctl(8) to	connect	to a configured	diagnostic port, in
	  the same manner as with client-side ppp.

	  Here,	the incoming section must be set up in /etc/ppp/ppp.conf.

	  Make sure that the incoming section contains the "allow users" com-
	  mand as appropriate.

     4.	  Prepare an account for the incoming user.

	  ppp:xxxx:66:66:PPP Login User:/home/ppp:/usr/local/bin/ppplogin

	  Refer	to the manual entries for adduser(8) and vipw(8) for details.

     5.	  Support for IPCP Domain Name Server and NetBIOS Name Server negotia-
	  tion can be enabled using the	"accept	dns" and "set nbns" commands.
	  Refer	to their descriptions below.

RECEIVING INCOMING PPP CONNECTIONS (Method 2)
     This method differs in that we use	ppp to authenticate the	connection
     rather than login(1):

     1.	  Configure your default section in /etc/gettytab with automatic ppp
	  recognition by specifying the	"pp" capability:

	  default:\
		  :pp=/usr/local/bin/ppplogin:\
		  .....

     2.	  Configure your serial	device(s), enable a getty(8) and create
	  /usr/local/bin/ppplogin as in	the first three	steps for method 1
	  above.

     3.	  Add either "enable chap" or "enable pap" (or both) to
	  /etc/ppp/ppp.conf under the `incoming' label (or whatever label
	  ppplogin uses).

     4.	  Create an entry in /etc/ppp/ppp.secret for each incoming user:

	  Pfred<TAB>xxxx
	  Pgeorge<TAB>yyyy

     Now, as soon as getty(8) detects a	ppp connection (by recognising the
     HDLC frame	headers), it runs "/usr/local/bin/ppplogin".

     It	is VITAL that either PAP or CHAP are enabled as	above.	If they	are
     not, you are allowing anybody to establish	a ppp session with your	ma-
     chine without a password, opening yourself	up to all sorts	of potential
     attacks.

AUTHENTICATING INCOMING	CONNECTIONS
     Normally, the receiver of a connection requires that the peer authenti-
     cates itself.  This may be	done using 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 `enable chap' or `enable pap' to the relevant section of
     ppp.conf.

     You must then configure the /etc/ppp/ppp.secret file.  This file contains
     one line per possible client, each	line containing	up to five fields:

     name key [hisaddr [label [callback-number]]]

     The name and key specify the client username and password.	 If key	is "*"
     and PAP is	being used, ppp	will look up the password database (passwd(5))
     when authenticating.  If the client does not offer	a suitable response
     based on any name/key combination in ppp.secret, authentication fails.

     If	authentication is successful, hisaddr (if specified) is	used when ne-
     gotiating IP numbers.  See	the "set ifaddr" command for details.

     If	authentication is successful and label is specified, the current sys-
     tem label is changed to match the given label.  This will change the sub-
     sequent parsing of	the ppp.linkup and ppp.linkdown	files.

     If	authentication is successful and callback-number is specified and "set
     callback" has been	used in	ppp.conf, the client will be called back on
     the given number.	If CBCP	is being used, callback-number may also	con-
     tain a list of numbers or a "*", as if passed to the "set cbcp" command.
     The value will be used in ppp's subsequent	CBCP phase.

PPP OVER TCP and UDP (a.k.a Tunnelling)
     Instead of	running	ppp over a serial link,	it is possible to use a	TCP
     connection	instead	by specifying the host,	port and protocol as the de-
     vice:

	   set device ui-gate:6669/tcp

     Instead of	opening	a serial device, ppp will open a TCP connection	to the
     given machine on the given	socket.	 It should be noted however that ppp
     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 PPP connec-
     tion on the receiving machine (ui-gate).  This is done by first updating
     /etc/services to name the service:

	   ppp-in 6669/tcp # Incoming PPP connections over TCP

     and updating /etc/inetd.conf to tell inetd(8) how to deal with incoming
     connections on that port:

	   ppp-in stream tcp nowait root /usr/sbin/ppp ppp -direct ppp-in

     Don't forget to send a HUP	signal to inetd(8) after you've	updated
     /etc/inetd.conf.  Here, we	use a label named "ppp-in".  The entry in
     /etc/ppp/ppp.conf on ui-gate (the receiver) should	contain	the following:

	   ppp-in:
	    set	timeout	0
	    set	ifaddr 10.0.4.1	10.0.4.2

     and the entry in /etc/ppp/ppp.linkup should contain:

	   ppp-in:
	    add	10.0.1.0/24 HISADDR

     It	is necessary to	put the	"add" command in ppp.linkup to ensure that the
     route is only added after ppp has negotiated and assigned addresses to
     its interface.

     You may also want to enable PAP or	CHAP for security.  To enable PAP, add
     the following line:

	    enable PAP

     You'll also need to create	the following entry in /etc/ppp/ppp.secret:

	   MyAuthName MyAuthPasswd

     If	MyAuthPasswd is	a "*", the password is looked up in the	passwd(5)
     database.

     The entry in /etc/ppp/ppp.conf on awfulhak	(the initiator)	should contain
     the following:

	   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 IPV6CP CCP	tun
	    set	ifaddr 10.0.4.2	10.0.4.1

     with the route setup in /etc/ppp/ppp.linkup:

	   ui-gate:
	    add	10.0.2.0/24 HISADDR

     Again, if you're enabling PAP, you'll also	need this in the
     /etc/ppp/ppp.conf profile:

	    set	authname MyAuthName
	    set	authkey	MyAuthKey

     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

	   awfulhak # ppp -background ui-gate

     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 un-
     derlying TCP connection may be across a public network (such as the In-
     ternet), and the PPP traffic is conceptually encapsulated (although not
     packet by packet) inside the TCP stream between the two gateways.

     The major disadvantage of this mechanism is that there are	two "guaran-
     teed delivery" mechanisms in place	- the underlying TCP stream and	what-
     ever protocol is used over	the 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.

     To	avoid this overhead, it	is also	possible to do all this	using UDP in-
     stead of TCP as the transport by simply changing the protocol from	"tcp"
     to	"udp".	When using UDP as a transport, ppp will	operate	in synchronous
     mode.  This is another gain as the	incoming data does not have to be re-
     arranged into packets.

     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
     /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:

	   ui-gate:
	    set	escape 0xff
	    set	device ui-gate:ppp-in/tcp
	    add	ui-gate	x.x.x.x
	    .....

     where "x.x.x.x" is	the IP number that your	route to "ui-gate" would nor-
     mally use.

     When routing your connection accross a public network such	as the Inter-
     net, 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 com-
     pression layer (thank Microsoft for this).	 To enable MPPE	encryption,
     add the following lines to	/etc/ppp/ppp.conf on the server:

	     enable MSCHAPv2
	     disable deflate pred1
	     deny deflate pred1

     ensuring that you've put the requisite entry in /etc/ppp/ppp.secret
     (MSCHAPv2 is challenge based, so passwd(5)	cannot be used)

     MSCHAPv2 and MPPE are accepted by default,	so the client end should work
     without any additional changes (although ensure you have "set authname"
     and "set authkey" in your profile).

NETWORK	ADDRESS	TRANSLATION (PACKET ALIASING)
     The -nat command line option enables network address translation (a.k.a.
     packet aliasing).	This allows the	ppp host to act	as a masquerading
     gateway for other computers over a	local area network.  Outgoing IP pack-
     ets are NAT'd so that they	appear to come from the	ppp 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 ppp operation should first be veri-
     fied with network address translation disabled.  Then, the	-nat option
     should be switched	on, and	network	applications (web browser, telnet(1),
     ftp(1), ping(8), traceroute(8)) should be checked on the ppp host.	 Fi-
     nally, the	same or	similar	applications should be checked on other	com-
     puters in the LAN.	 If network applications work correctly	on the ppp
     host, but not on other machines in	the LAN, then the masquerading soft-
     ware is working properly, but the host is either not forwarding or	possi-
     bly receiving IP packets.	Check that IP forwarding is enabled in
     /etc/rc.conf and that other machines have designated the ppp host as the
     gateway for the LAN.

PACKET FILTERING
     This implementation supports packet filtering.  There are four kinds of
     filters: the in filter, the out filter, the dial filter and the alive
     filter.  Here are the basics:

     +o	 A filter definition has the following syntax:

	 set filter name rule-no action	[!] [[host] src_addr[/width]
	 [dst_addr[/width]]] [proto [src cmp port] [dst	cmp port] [estab]
	 [syn] [finrst]	[timeout secs]]

	 1.   Name should be one of `in', `out', `dial'	or `alive'.

	 2.   Rule-no is a numeric value between `0' and `39' specifying the
	      rule number.  Rules are specified	in numeric order according to
	      rule-no, but only	if rule	`0' is defined.

	 3.   Action may be specified as `permit' or `deny', in	which case, if
	      a	given packet matches the rule, the associated action is	taken
	      immediately.  Action can also be specified as `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).

	      The action may optionally	be followed with an exclamation	mark
	      ("!"), telling ppp to reverse the	sense of the following match.

	 4.   [src_addr[/width]] and [dst_addr[/width]]	are the	source and
	      destination IP number specifications.  If	[/width] is specified,
	      it gives the number of relevant netmask bits, allowing the spec-
	      ification	of an address range.

	      Either src_addr or dst_addr may be given the values MYADDR,
	      HISADDR, MYADDR6 or HISADDR6 (refer to the description of	the
	      "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 "add" command
	      below.

	 5.   Proto may	be any protocol	from protocols(5).

	 6.   Cmp is one of `lt', `eq' or `gt',	meaning	less-than, equal and
	      greater-than respectively.  Port can be specified	as a numeric
	      port or by service name from /etc/services.

	 7.   The `estab', `syn', and `finrst' flags are only allowed when
	      proto is set to `tcp', and represent the TH_ACK, TH_SYN and
	      TH_FIN or	TH_RST TCP flags respectively.

	 8.   The timeout value	adjusts	the current idle timeout to at least
	      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	time-
	      out is given, the	default	timeout	(set using set timeout and de-
	      faulting to 180 seconds) is used.

     +o	 Each filter can hold up to 40 rules, starting from rule 0.  The en-
	 tire rule set is not effective	until rule 0 is	defined, i.e., the de-
	 fault is to allow everything through.

     +o	 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	fil-
	 ter, the packet will be permitted.

     +o	 It's possible to filter based on the payload of UDP frames where
	 those frames contain a	PROTO_IP PPP frame header.  See	the
	 filter-decapsulation option below for further details.

     +o	 Use "set filter name -1" to flush all rules.

     See /usr/share/examples/ppp/ppp.conf.sample.

SETTING	THE IDLE TIMER
     To	check/set the idle timer, use the "show	bundle"	and "set timeout" com-
     mands:

	   ppp ON awfulhak> set	timeout	600

     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 com-
     mand

	   ppp ON awfulhak> set	timeout	0

     In	-ddial and -dedicated modes, the idle timeout is ignored.  In -auto
     mode, when	the idle timeout causes	the PPP	session	to be closed, the ppp
     program itself remains running.  Another trigger packet will cause	it to
     attempt to	re-establish the link.

PREDICTOR-1 and	DEFLATE	COMPRESSION
     ppp supports both Predictor type 1	and deflate compression.  By default,
     ppp will attempt to use (or be willing to accept) both compression	proto-
     cols when the peer	agrees (or requests them).  The	deflate	protocol is
     preferred by ppp.	Refer to the "disable" and "deny" commands if you wish
     to	disable	this functionality.

     It	is possible to use a different compression algorithm in	each direction
     by	using only one of "disable deflate" and	"deny deflate" (assuming that
     the peer supports both algorithms).

     By	default, when negotiating DEFLATE, ppp will use	a window size of 15.
     Refer to the "set deflate"	command	if you wish to change this behaviour.

     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 ppp to successfully negoti-
     ate DEFLATE with pppd version 2.3.*.

CONTROLLING IP ADDRESS
     For IPv4, ppp uses	IPCP to	negotiate IP addresses.	 Each side of the con-
     nection specifies the IP address that it's	willing	to use,	and if the re-
     quested IP	address	is acceptable then ppp returns an ACK to the re-
     quester.  Otherwise, ppp returns NAK to suggest that the peer use a dif-
     ferent IP address.	 When both sides of the	connection agree to accept the
     received request (and send	an ACK), IPCP is set to	the open state and a
     network level connection is established.  To control this IPCP behaviour,
     this implementation has the "set ifaddr" command for defining the local
     and remote	IP address:

	   set ifaddr [src_addr[/nn] [dst_addr[/nn] [netmask [trigger_addr]]]]

     where, `src_addr' is the IP address that the local	side is	willing	to
     use, `dst_addr' is	the IP address which the remote	side should use	and
     `netmask' is the netmask that should be used.  `Src_addr' defaults	to the
     current hostname(1), `dst_addr' defaults to 0.0.0.0, and `netmask'	de-
     faults to whatever	mask is	appropriate for	`src_addr'.  It	is only	possi-
     ble to make `netmask' smaller than	the default.  The usual	value is
     255.255.255.255, as most kernels ignore the netmask of a POINTOPOINT in-
     terface.

     Some incorrect PPP	implementations	require	that the peer negotiates a
     specific IP address instead of `src_addr'.	 If this is the	case,
     `trigger_addr' may	be used	to specify this	IP number.  This will not af-
     fect the routing table unless the other side agrees with this proposed
     number.

	   set ifaddr 192.244.177.38 192.244.177.2 255.255.255.255 0.0.0.0

     The above specification means:

     +o	 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.
     +o	 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.
     +o	 The routing table entry will have a netmask of	0xffffffff.

     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	"set ifaddr" command allows the	user
     to	specify	IP addresses more loosely:

	   set ifaddr 192.244.177.38/24	192.244.177.2/20

     A number followed by a slash ("/")	represents the number of bits signifi-
     cant in the IP address.  The above	example	means:

     +o	 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.
     +o	 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.
     +o	 As you	may have already noticed, 192.244.177.2	is equivalent to say-
	 ing 192.244.177.2/32.
     +o	 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.
     +o	 192.244.177.2/0 means that I'll accept/permit any IP address but I'll
	 suggest that 192.244.177.2 be used first.

     When negotiating IPv6 addresses, no control is given to the user.	IPV6CP
     negotiation is fully automatic.

CONNECTING WITH	YOUR INTERNET SERVICE PROVIDER
     The following steps should	be taken when connecting to your ISP:

     1.	  Describe your	providers phone	number(s) in the dial script using the
	  "set phone" command.	This command allows you	to set multiple	phone
	  numbers for dialing and redialing separated by either	a pipe ("|")
	  or a colon (":"):

		set phone telno[|backupnumber]...[:nextnumber]...

	  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.  Num-
	  bers separated by a colon are	used sequentially, irrespective	of
	  what happened	as a result of using the previous number.  For exam-
	  ple:

		set phone "1234567|2345678:3456789|4567890"

	  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 "set dial" command
	  (see below).

     2.	  Set up your redial requirements using	"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:

		set redial 10 4

	  This says that up to 4 phone calls should be attempted with a	pause
	  of 10	seconds	before dialing the first number	again.

     3.	  Describe your	login procedure	using the "set dial" and "set login"
	  commands.  The "set dial" command is used to talk to your modem and
	  establish a link with	your ISP, for example:

		set dial "ABORT	BUSY ABORT NO\\sCARRIER	TIMEOUT	4 \"\" \
		  ATZ OK-ATZ-OK	ATDT\\T	TIMEOUT	60 CONNECT"

	  This modem "chat" string means:

	  +o   Abort if the string "BUSY" or "NO	CARRIER" are received.

	  +o   Set the timeout to 4 seconds.

	  +o   Expect nothing.

	  +o   Send ATZ.

	  +o   Expect OK.  If that's not	received within	the 4 second timeout,
	      send ATZ and expect OK.

	  +o   Send ATDTxxxxxxx where xxxxxxx is	the next number	in the phone
	      list from	above.

	  +o   Set the timeout to 60.

	  +o   Wait for the CONNECT string.

	  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:

		set authkey MySecret
		set login "TIMEOUT 15 login:-\\r-login:	awfulhak \
		  word:	\\P ocol: PPP HELLO"

	  This login "chat" string means:

	  +o   Set the timeout to 15 seconds.

	  +o   Expect "login:".	If it's	not received, send a carriage return
	      and expect "login:" again.

	  +o   Send "awfulhak"

	  +o   Expect "word:" (the tail end of a	"Password:" prompt).

	  +o   Send whatever our	current	authkey	value is set to.

	  +o   Expect "ocol:" (the tail end of a	"Protocol:" prompt).

	  +o   Send "PPP".

	  +o   Expect "HELLO".

	  The "set authkey" command is logged specially.  When command or chat
	  logging is enabled, the actual password is not logged; `********' is
	  logged instead.

	  Login	scripts	vary greatly between ISPs.  If you're setting one up
	  for the first	time, ENABLE CHAT LOGGING so that you can see if your
	  script is behaving as	you expect.

     4.	  Use "set device" and "set speed" to specify your serial line and
	  speed, for example:

		set device /dev/cuaa0
		set speed 115200

	  Cuaa0	is the first serial port on FreeBSD.  If you're	running	ppp on
	  OpenBSD, 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 gen-
	  eral,	the serial speed should	be about four times the	modem speed.

     5.	  Use the "set ifaddr" command to define the IP	address.

	  +o   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).

	  +o   If your provider has assigned a particular IP address to you,
	      then use it as your address (src_addr).

	  +o   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.

	  +o   If you find that your ISP	accepts	the first IP number that you
	      suggest, specify third and forth arguments of "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 `src_addr').

	  An example for a connection where you	don't know your	IP number or
	  your ISPs IP number would be:

		set ifaddr 10.0.0.1/0 10.0.0.2/0 0.0.0.0 0.0.0.0

     6.	  In most cases, your ISP will also be your default router.  If	this
	  is the case, add the line

		add default HISADDR

	  to /etc/ppp/ppp.conf (or to /etc/ppp/ppp.linkup for setups that
	  don't	use -auto mode).

	  This tells ppp to add	a default route	to whatever the	peer address
	  is (10.0.0.2 in this example).  This route is	`sticky', meaning that
	  should the value of HISADDR change, the route	will be	updated	ac-
	  cordingly.

     7.	  If your provider requests that you use PAP/CHAP authentication meth-
	  ods, add the next lines to your /etc/ppp/ppp.conf file:

		set authname MyName
		set authkey MyPassword

	  Both are accepted by default,	so ppp will provide whatever your ISP
	  requires.

	  It should be noted that a login script is rarely (if ever) required
	  when PAP or CHAP are in use.

     8.	  Ask your ISP to authenticate your nameserver address(es) with	the
	  line

		enable dns

	  Do NOT do this if you	are running a local DNS	unless you also	either
	  use "resolv readonly"	or have	"resolv	restore" in
	  /etc/ppp/ppp.linkdown, as ppp	will simply circumvent its use by en-
	  tering some nameserver lines in /etc/resolv.conf.

     Please refer to /usr/share/examples/ppp/ppp.conf.sample and
     /usr/share/examples/ppp/ppp.linkup.sample for some	real examples.	The
     pmdemand label should be appropriate for most ISPs.

LOGGING	FACILITY
     ppp is able to generate the following log info either via syslog(3) or
     directly to the screen:

	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.)
	Async	   Dump	async level packet in hex.
	CBCP	   Generate CBCP (CallBack Control Protocol) logs.
	CCP	   Generate a CCP packet trace.
	Chat	   Generate `dial', `login', `logout' and `hangup' chat	script
		   trace logs.
	Command	   Log commands	executed either	from the command line or any
		   of the configuration	files.
	Connect	   Log Chat lines containing the string	"CONNECT".
	Debug	   Log debug information.
	DNS	   Log DNS QUERY packets.
	Filter	   Log packets permitted by the	dial filter and	denied by any
		   filter.
	HDLC	   Dump	HDLC packet in hex.
	ID0	   Log all function calls specifically made as user id 0.
	IPCP	   Generate an IPCP packet trace.
	LCP	   Generate an LCP packet trace.
	LQM	   Generate LQR	reports.
	Phase	   Phase transition log	output.
	Physical   Dump	physical level packet in hex.
	Radius	   Dump	RADIUS information.  RADIUS information	resulting from
		   the link coming up or down is logged	at "Phase" level un-
		   less	"Radius" logging is enabled.  This log level is	most
		   useful for monitoring RADIUS	alive information.
	Sync	   Dump	sync level packet in hex.
	TCP/IP	   Dump	all TCP/IP packets.
	Timer	   Log timer manipulation.
	TUN	   Include the tun device on each log line.
	Warning	   Output to the terminal device.  If there is currently no
		   terminal, output is sent to the log file using syslogs
		   LOG_WARNING.
	Error	   Output to both the terminal device and the log file using
		   syslogs LOG_ERROR.
	Alert	   Output to the log file using	LOG_ALERT.

     The "set log" command allows you to set the logging output	level.	Multi-
     ple levels	can be specified on a single command line.  The	default	is
     equivalent	to "set	log Phase".

     It	is also	possible to log	directly to the	screen.	 The syntax is the
     same except that the word "local" should immediately follow "set log".
     The default is "set log local" (i.e., only	the un-maskable	warning, error
     and alert output).

     If	The first argument to "set log [local]"	begins with a `+' or a `-'
     character,	the current log	levels are not cleared,	for example:

	   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

     Log messages of level Warning, Error and Alert are	not controllable using
     "set log [local]".

     The Warning level is special in that it will not be logged	if it can be
     displayed locally.

SIGNAL HANDLING
     ppp deals with the	following signals:

     INT   Receipt of this signal causes the termination of the	current	con-
	   nection (if any).  This will	cause ppp to exit unless it is in
	   -auto or -ddial mode.

     HUP, TERM & QUIT
	   These signals tell ppp to exit.

     USR1  This	signal,	tells ppp to re-open any existing server socket, drop-
	   ping	all existing diagnostic	connections.  Sockets that couldn't
	   previously be opened	will be	retried.

     USR2  This	signal,	tells ppp to close any existing	server socket, drop-
	   ping	all existing diagnostic	connections.  SIGUSR1 can still	be
	   used	to re-open the socket.

MULTI-LINK PPP
     If	you wish to use	more than one physical link to connect to a PPP	peer,
     that peer must also understand the	MULTI-LINK PPP protocol.  Refer	to RFC
     1990 for specification details.

     The peer is identified using a combination	of his "endpoint
     discriminator" and	his "authentication id".  Either or both of these may
     be	specified.  It is recommended that at least one	is specified, other-
     wise 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 "set enddisc" and
     "set authname" commands.  The `authname' (and `authkey') must be agreed
     in	advance	with the peer.

     Multi-link	capabilities are enabled using the "set	mrru" command (set
     maximum reconstructed receive unit).  Once	multi-link is enabled, ppp
     will attempt to negotiate a multi-link connection with the	peer.

     By	default, only one `link' is available (called `deflink').  To create
     more links, the "clone" command is	used.  This command will clone exist-
     ing links,	where all characteristics are the same except:

     1.	  The new link has its own name	as specified on	the "clone" command
	  line.

     2.	  The new link is an `interactive' link.  Its mode may subsequently be
	  changed using	the "set mode" command.

     3.	  The new link is in a `closed'	state.

     A summary of all available	links can be seen using	the "show links" com-
     mand.

     Once a new	link has been created, command usage varies.  All link spe-
     cific commands must be prefixed with the "link name" command, specifying
     on	which link the command is to be	applied.  When only a single link is
     available,	ppp is smart enough not	to require the "link name" prefix.

     Some commands can still be	used without specifying	a link - resulting in
     an	operation at the `bundle' level.  For example, once two	or more	links
     are available, the	command	"show ccp" will	show CCP configuration and
     statistics	at the multi-link level, and "link deflink show	ccp" will show
     the same information at the "deflink" link	level.

     Armed with	this information, the following	configuration might be used:

	   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 \
		      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'')

     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.

	     link 1,2,3	set mode ddial

     If	you want the links to dial on demand, this command could be used:

	     link * set	mode auto

     Links may be tied to specific names by removing the "set device" line
     above, and	specifying the following after the "clone" command:

	    link 1 set device /dev/cuaa0
	    link 2 set device /dev/cuaa1
	    link 3 set device /dev/cuaa2

     Use the "help" command to see which commands require context (using the
     "link" command), which have optional context and which should not have
     any context.

     When ppp has negotiated MULTI-LINK	mode with the peer, it creates a local
     domain socket in the /var/run directory.  This socket is used to pass
     link information (including the actual link file descriptor) between dif-
     ferent ppp	invocations.  This facilitates ppp's ability to	be run from a
     getty(8) or directly from /etc/gettydefs (using the `pp=' capability),
     without needing to	have initial control of	the serial line.  Once ppp ne-
     gotiates multi-link mode, it will pass its	open link to any already run-
     ning process.  If there is	no already running process, ppp	will act as
     the master, creating the socket and listening for new connections.

PPP COMMAND LIST
     This section lists	the available commands and their effect.  They are us-
     able either from an interactive ppp session, from a configuration file or
     from a pppctl(8) or telnet(1) session.

     accept|deny|enable|disable	option....
	 These directives tell ppp how to negotiate the	initial	connection
	 with the peer.	 Each "option" has a default of	either accept or deny
	 and enable or disable.	 "Accept" means	that the option	will be	ACK'd
	 if the	peer asks for it.  "Deny" means	that the option	will be	NAK'd
	 if the	peer asks for it.  "Enable" means that the option will be re-
	 quested by us.	 "Disable" means that the option will not be requested
	 by us.

	 "Option" may be one of	the following:

	 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 op-
	     tion is negotiated, these two bytes are simply not	sent, thus
	     minimising	traffic.

	     See rfc1662 for details.

	 chap[05]
	     Default: Disabled and Accepted.  CHAP stands for Challenge	Hand-
	     shake Authentication Protocol.  Only one of CHAP and PAP (below)
	     may be negotiated.	 With CHAP, the	authenticator sends a "chal-
	     lenge" message to its peer.  The peer uses	a one-way hash func-
	     tion to encrypt the challenge and sends the result	back.  The au-
	     thenticator does the same,	and compares the results.  The advan-
	     tage 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	"enable	chap".	in
	     /etc/ppp/ppp.conf,	and have an entry in /etc/ppp/ppp.secret for
	     the peer.

	     When using	CHAP as	the client, you	need only specify "AuthName"
	     and "AuthKey" in /etc/ppp/ppp.conf.  CHAP is accepted by default.
	     Some PPP implementations use "MS-CHAP" rather than	MD5 when en-
	     crypting the challenge.  MS-CHAP is a combination of MD4 and DES.
	     If	ppp was	built on a machine with	DES libraries available, it
	     will respond to MS-CHAP authentication requests, but will never
	     request them.

	 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 gzip(1) pro-
	     gram.  Note: There	is a problem negotiating deflate capabilities
	     with pppd(8) - a PPP implementation available under many operat-
	     ing systems.  pppd	(version 2.3.1)	incorrectly attempts to	nego-
	     tiate deflate compression using type 24 as	the CCP	configuration
	     type rather than type 26 as specified in rfc1979.	Type 24	is ac-
	     tually specified as "PPP Magna-link Variable Resource
	     Compression" in rfc1975!  ppp is capable of negotiating with
	     pppd, but only if "deflate24" is enabled and accepted.

	 deflate24
	     Default: Disabled and Denied.  This is a variance of the deflate
	     option, allowing negotiation with the pppd(8) program.  Refer to
	     the deflate section above for details.  It	is disabled by default
	     as	it violates rfc1975.

	 dns
	     Default: Disabled and Denied.  This option	allows DNS negotia-
	     tion.

	     If	"enabled," ppp will request that the peer confirms the entries
	     in	/etc/resolv.conf.  If the peer NAKs our	request	(suggesting
	     new IP numbers), /etc/resolv.conf is updated and another request
	     is	sent to	confirm	the new	entries.

	     If	"accepted," ppp	will answer any	DNS queries requested by the
	     peer rather than rejecting	them.  The answer is taken from
	     /etc/resolv.conf unless the "set dns" command is used as an over-
	     ride.

	 enddisc
	     Default: Enabled and Accepted.  This option allows	control	over
	     whether we	negotiate an endpoint discriminator.  We only send our
	     discriminator if "set enddisc" is used and	enddisc	is enabled.
	     We	reject the peers discriminator if enddisc is denied.

	 LANMan|chap80lm
	     Default: Disabled and Accepted.  The use of this authentication
	     protocol is discouraged as	it partially violates the authentica-
	     tion protocol by implementing two different mechanisms (LANMan &
	     NT) under the guise of a single CHAP type (0x80).	"LANMan" uses
	     a simple DES encryption mechanism and is the least	secure of the
	     CHAP alternatives (although is still more secure than PAP).

	     Refer to the "MSChap" description below for more details.

	 lqr
	     Default: Disabled and Accepted.  This option decides if Link
	     Quality Requests will be sent or accepted.	 LQR is	a protocol
	     that allows ppp to	determine that the link	is down	without	rely-
	     ing on the	modems carrier detect.	When LQR is enabled, ppp sends
	     the QUALPROTO option (see "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,
	     and if the	"echo" option is enabled, ppp will send	LCP ECHO re-
	     quests instead.  These packets pass no information	of interest,
	     but they MUST be replied to by the	peer.

	     Whether using LQR or LCP ECHO, ppp	will abruptly drop the connec-
	     tion if 5 unacknowledged packets have been	sent rather than send-
	     ing a 6th.	 A message is logged at	the PHASE level, and any ap-
	     propriate "reconnect" values are honoured as if the peer were re-
	     sponsible for dropping the	connection.

	     Refer to the "enable echo"	command	description for	differences in
	     behaviour prior to	ppp version 3.4.2.

	 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 "set mppe" command.

	 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 mecha-
	     nism.

	 MSChap|chap80nt
	     Default: Disabled and Accepted.  The use of this authentication
	     protocol is discouraged as	it partially violates the authentica-
	     tion 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	chal-
	     lenges 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
	     "enable LANMan" for details.

	     Because both "LANMan" and "NT" use	CHAP type 0x80,	when acting as
	     authenticator with	both "enabled",	ppp 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.

	     Conversely, when ppp acts as the authenticatee with both proto-
	     cols "accepted", the protocols are	used alternately in response
	     to	challenges.

	     Note: If only LANMan is enabled, pppd(8) (version 2.3.5) misbe-
	     haves when	acting as authenticatee.  It provides both the NT and
	     the LANMan	answers, but also suggests that	only the NT answer
	     should be used.

	 pap
	     Default: Disabled and Accepted.  PAP stands for Password Authen-
	     tication Protocol.	 Only one of PAP and CHAP (above) may be nego-
	     tiated.  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 "enable
	     pap".  in /etc/ppp/ppp.conf, and have an entry in
	     /etc/ppp/ppp.secret for the peer (although	see the	"passwdauth"
	     and "set radius" options below).

	     When using	PAP as the client, you need only specify "AuthName"
	     and "AuthKey" in /etc/ppp/ppp.conf.  PAP is accepted by default.

	 pred1
	     Default: Enabled and Accepted.  This option decides if Predictor
	     1 compression will	be used	by the Compression Control Protocol
	     (CCP).

	 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.

	 shortseq
	     Default: Enabled and Accepted.  This option determines if ppp
	     will request and accept requests for short	(12 bit) sequence num-
	     bers when negotiating multi-link mode.  This is only applicable
	     if	our MRRU is set	(thus enabling multi-link).

	 vjcomp
	     Default: Enabled and Accepted.  This option determines if Van Ja-
	     cobson header compression will be used.

	 The following options are not actually	negotiated with	the peer.
	 Therefore, accepting or denying them makes no sense.

	 echo
	     Default: Disabled.	 When this option is enabled, ppp will send
	     LCP ECHO requests to the peer at the frequency defined by
	     "echoperiod".  Note, LQR requests will supersede LCP ECHO re-
	     quests if enabled and negotiated.	See "set lqrperiod" below for
	     details.

	     Prior to ppp version 3.4.2, "echo"	was considered enabled if lqr
	     was enabled and negotiated, otherwise it was considered disabled.
	     For the same behaviour, it	is now necessary to "enable lqr	echo"
	     rather than just "enable lqr".

	 filter-decapsulation
	     Default: Disabled.	 When this option is enabled, ppp will examine
	     UDP frames	to see if they actually	contain	a PPP frame as their
	     payload.  If this is the case, all	filters	will operate on	the
	     payload rather than the actual packet.

	     This is useful if you want	to send	PPPoUDP	traffic	over a PPP
	     link, but want that link to do smart things with the real data
	     rather than the UDP wrapper.

	     The UDP frame payload must	not be compressed in any way, other-
	     wise ppp will not be able to interpret it.	 It's therefore	recom-
	     mended that you disable vj	pred1 deflate and deny vj pred1
	     deflate in	the configuration for the ppp invocation with the udp
	     link.

	 force-scripts
	     Default: Disabled.	 Forces	execution of the configured chat
	     scripts in	direct and dedicated modes.

	 idcheck
	     Default: Enabled.	When ppp exchanges low-level LCP, CCP and IPCP
	     configuration traffic, the	Identifier field of any	replies	is ex-
	     pected to be the same as that of the request.  By default,	ppp
	     drops any reply packets that do not contain the expected identi-
	     fier field, reporting the fact at the respective log level.  If
	     idcheck is	disabled, ppp will ignore the identifier field.

	 iface-alias
	     Default: Enabled if -nat is specified.  This option simply	tells
	     ppp to add	new interface addresses	to the interface rather	than
	     replacing them.  The option can only be enabled if	network	ad-
	     dress translation is enabled ("nat	enable yes").

	     With this option enabled, ppp will	pass traffic for old interface
	     addresses through the NAT engine (see libalias(3)), resulting in
	     the ability (in -auto mode) to properly connect the process that
	     caused the	PPP link to come up in the first place.

	     Disabling NAT with	"nat enable no"	will also disable
	     `iface-alias'.

	 ipcp
	     Default: Enabled.	This option allows ppp to attempt to negotiate
	     IP	control	protocol capabilities and if successful	to exchange IP
	     datagrams with the	peer.

	 ipv6cp
	     Default: Enabled.	This option allows ppp to attempt to negotiate
	     IPv6 control protocol capabilities	and if successful to exchange
	     IPv6 datagrams with the peer.

	 keep-session
	     Default: Disabled.	 When ppp runs as a Multi-link server, a dif-
	     ferent ppp	instance initially receives each connection.  After
	     determining that the link belongs to an already existing bundle
	     (controlled by another ppp	invocation), ppp will transfer the
	     link to that process.

	     If	the link is a tty device or if this option is enabled, ppp
	     will not exit, but	will change its	process	name to	"session
	     owner" and	wait for the controlling ppp to	finish with the	link
	     and deliver a signal back to the idle process.  This prevents the
	     confusion that results from ppp's parent considering the link re-
	     source available again.

	     For tty devices that have entries in /etc/ttys, this is necessary
	     to	prevent	another	getty(8) from being started, and for program
	     links such	as sshd(8), it prevents	sshd(8)	from exiting due to
	     the death of its child.  As ppp cannot determine its parents re-
	     quirements	(except	for the	tty case), this	option must be enabled
	     manually depending	on the circumstances.

	 loopback
	     Default: Enabled.	When loopback is enabled, ppp will automati-
	     cally loop	back packets being sent	out with a destination address
	     equal to that of the PPP interface.  If disabled, ppp will	send
	     the packet, probably resulting in an ICMP redirect	from the other
	     end.  It is convenient to have this option	enabled	when the in-
	     terface is	also the default route as it avoids the	necessity of a
	     loopback route.

	 NAS-IP-Address
	     Default: Enabled.	This option controls whether ppp sends the
	     "NAS-IP-Address" attribute	to the RADIUS server when RADIUS is in
	     use (see "set radius").

	     Note, at least one	of "NAS-IP-Address" and	"NAS-Identifier" must
	     be	enabled.

	     Versions of ppp prior to version 3.4.1 did	not send the
	     "NAS-IP-Address" atribute as it was reported to break the Radia-
	     tor RADIUS	server.	 As the	latest rfc (2865) no longer hints that
	     only one of "NAS-IP-Address" and "NAS-Identifier" should be sent
	     (as rfc 2138 did),	ppp now	sends both and leaves it up to the ad-
	     ministrator that chooses to use bad RADIUS	implementations	to
	     "disable NAS-IP-Address".

	 NAS-Identifier
	     Default: Enabled.	This option controls whether ppp sends the
	     "NAS-Identifier" attribute	to the RADIUS server when RADIUS is in
	     use (see "set radius").

	     Note, at least one	of "NAS-IP-Address" and	"NAS-Identifier" must
	     be	enabled.

	 passwdauth
	     Default: Disabled.	 Enabling this option will tell	the PAP	au-
	     thentication code to use the password database (see passwd(5)) to
	     authenticate the caller if	they cannot be found in	the
	     /etc/ppp/ppp.secret file.	/etc/ppp/ppp.secret is always checked
	     first.  If	you wish to use	passwords from passwd(5), but also to
	     specify an	IP number or label for a given client, use "*" as the
	     client password in	/etc/ppp/ppp.secret.

	 proxy
	     Default: Disabled.	 Enabling this option will tell	ppp to proxy
	     ARP for the peer.	This means that	ppp will make an entry in the
	     ARP table using HISADDR and the MAC address of the	local network
	     in	which HISADDR appears.	This allows other machines connecteed
	     to	the LAN	to talk	to the peer as if the peer itself was con-
	     nected to the LAN.	 The proxy entry cannot	be made	unless HISADDR
	     is	an address from	a LAN.

	 proxyall
	     Default: Disabled.	 Enabling this will tell ppp to	add proxy arp
	     entries for every IP address in all class C or smaller subnets
	     routed via	the tun	interface.

	     Proxy arp entries are only	made for sticky	routes that are	added
	     using the "add" command.  No proxy	arp entries are	made for the
	     interface address itself (as created by the "set ifaddr" com-
	     mand).

	 sroutes
	     Default: Enabled.	When the "add" command is used with the
	     HISADDR, MYADDR, HISADDR6 or MYADDR6 values, entries are stored
	     in	the `sticky route' list.  Each time these variables change,
	     this list is re-applied to	the routing table.

	     Disabling this option will	prevent	the re-application of sticky
	     routes, although the `stick route'	list will still	be maintained.

	 [tcp]mssfixup
	     Default: Enabled.	This option tells ppp to adjust	TCP SYN	pack-
	     ets so that the maximum receive segment size is not greater than
	     the amount	allowed	by the interface MTU.

	 throughput
	     Default: Enabled.	This option tells ppp 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 PPP layer	shuts down, and	is
	     also available using the "show" command.  Throughput statistics
	     are available at the "IPCP" and "physical"	levels.

	 utmp
	     Default: Enabled.	Normally, when a user is authenticated using
	     PAP or CHAP, and when ppp is running in -direct mode, an entry is
	     made in the utmp and wtmp files for that user.  Disabling this
	     option will tell ppp not to make any utmp or wtmp entries.	 This
	     is	usually	only necessary if you require the user to both login
	     and authenticate themselves.

     add[!] dest[/nn] [mask] [gateway]
	 Dest is the destination IP address.  The netmask is specified either
	 as a number of	bits with /nn or as an IP number using mask.  0	0 or
	 simply	0 with no mask refers to the default route.  It	is also	possi-
	 ble to	use the	literal	name `default' instead of 0.  Gateway is the
	 next hop gateway to get to the	given dest machine/network.  Refer to
	 the route(8) command for further details.

	 It is possible	to use the symbolic names `MYADDR', `HISADDR',
	 `MYADDR6' or `HISADDR6' as the	destination, and `HISADDR' or
	 `HISADDR6' as the gateway.  `MYADDR' is replaced with the interface
	 IP address, `HISADDR' is replaced with	the interface IP destination
	 (peer)	address, `MYADDR6' is replaced with the	interface IPv6 ad-
	 dress,	and `HISADDR6' is replaced with	the interface IPv6 destination
	 address,

	 If the	add! command is	used (note the trailing	"!"), then if the
	 route already exists, it will be updated as with the `route change'
	 command (see route(8) for further details).

	 Routes	that contain the "HISADDR", "MYADDR", "HISADDR6", "MYADDR6",
	 "DNS0", or "DNS1" constants are considered `sticky'.  They are	stored
	 in a list (use	"show ncp" to see the list), and each time the value
	 of one	of these variables changes, the	appropriate routing table en-
	 tries are updated.  This facility may be disabled using "disable
	 sroutes".

     allow command [args]
	 This command controls access to ppp and its configuration files.  It
	 is possible to	allow user-level access, depending on the configura-
	 tion file label and on	the mode that ppp is being run in.  For	exam-
	 ple, you may wish to configure	ppp so that only user `fred' may ac-
	 cess label `fredlabel'	in -background mode.

	 User id 0 is immune to	these commands.

	 allow user[s] logname...
	     By	default, only user id 0	is allowed access to ppp.  If this
	     command is	used, all of the listed	users are allowed access to
	     the section in which the "allow users" command is found.  The
	     `default' section is always checked first (even though it is only
	     ever automatically	loaded at startup).  "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	`default' section, and then
	     specifying	a new user list	for that label.

	     If	user `*' is specified, access is allowed to all	users.

	 allow mode[s] mode...
	     By	default, access	using any ppp mode is possible.	 If this com-
	     mand is used, it restricts	the access modes allowed to load the
	     label under which this command is specified.  Again, as with the
	     "allow users" command, each "allow	modes" command overrides any
	     previous settings,	and the	`default' section is always checked
	     first.

	     Possible modes are: `interactive',	`auto',	`direct', `dedicated',
	     `ddial', `background' and `*'.

	     When running in multi-link	mode, a	section	can be loaded if it
	     allows any	of the currently existing line modes.

     nat command [args]
	 This command allows the control of the	network	address	translation
	 (also known as	masquerading or	IP aliasing) facilities	that are built
	 into ppp.  NAT	is done	on the external	interface only,	and is un-
	 likely	to make	sense if used with the -direct flag.

	 If nat	is enabled on your system (it may be omitted at	compile	time),
	 the following commands	are possible:

	 nat enable yes|no
	     This command either switches network address translation on or
	     turns it off.  The	-nat command line flag is synonymous with "nat
	     enable yes".

	 nat addr [addr_local addr_alias]
	     This command allows data for addr_alias to	be redirected to
	     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.

	 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
	     CONCEPTUAL	BACKGROUND section of libalias(3) for a	description of
	     what an "aliasing link" is.

	     It	should be noted	under what circumstances an aliasing link is
	     created by	libalias(3).  It may be	necessary to further protect
	     your network from outside connections using the "set filter" or
	     "nat target" commands.

	 nat help|?
	     This command gives	a summary of available nat commands.

	 nat log yes|no
	     This option causes	various	NAT statistics and information to be
	     logged to the file	/var/log/alias.log.

	 nat port proto	targetIP:targetPort[-targetPort] aliasPort[-aliasPort]
	     [remoteIP:remotePort[-remotePort]]
	     This command causes incoming proto	connections to aliasPort to be
	     redirected	to targetPort on targetIP.  proto is either "tcp" or
	     "udp".

	     A range of	port numbers may be specified as shown above.  The
	     ranges must be of the same	size.

	     If	remoteIP is specified, only data coming	from that IP number is
	     redirected.  remotePort must either be "0"	(indicating any	source
	     port) or a	range of ports the same	size as	the other ranges.

	     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.

	 nat proto proto localIP [publicIP [remoteIP]]
	     This command tells	ppp to redirect	packets	of protocol type proto
	     (see protocols(5))	to the internal	address	localIP.

	     If	publicIP is specified, only packets destined for that address
	     are matched, otherwise the	default	alias address is used.

	     If	remoteIP is specified, only packets matching that source ad-
	     dress are matched,

	     This command is useful for	redirecting tunnel endpoints to	an in-
	     ternal machine, for example:

		   nat proto ipencap 10.0.0.1

	 nat proxy cmd arg...
	     This command tells	ppp to proxy certain connections, redirecting
	     them to a given server.  Refer to the description of
	     PacketAliasProxyRule() in libalias(3) for details of the avail-
	     able commands.

	 nat punch_fw [base count]
	     This command tells	ppp 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.

	     A maximum of count	rules starting from rule number	base will be
	     used for punching firewall	holes.	The range will be cleared when
	     the "nat punch_fw"	command	is run.

	     If	no arguments are given,	firewall punching is disabled.

	 nat skinny_port [port]
	     This command tells	ppp which TCP port is used by the Skinny Sta-
	     tion protocol.  Skinny is used by Cisco IP	phones to communicate
	     with Cisco	Call Managers to setup voice over IP calls.  The typi-
	     cal port used by Skinny is	2000.

	     If	no argument is given, skinny aliasing is disabled.

	 nat same_ports	yes|no
	     When enabled, this	command	will tell the network address transla-
	     tion engine to attempt to avoid changing the port number on out-
	     going 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.

	 nat target [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 in-
	     coming packets by default.	 If a target address is	not set	or if
	     "default" is given, packets are not altered and are allowed to
	     route to the internal network.

	     The target	address	may be set to "MYADDR",	in which case libalias
	     will redirect all packets to the interface	address.

	 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 in-
	     coming ftp	data or	IRC connection.

	 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.

	 These commands	are also discussed in the file README.nat which	comes
	 with the source distribution.

     [!]bg command
	 The given command is executed in the background with the following
	 words replaced:

	 AUTHNAME	  This is replaced with	the local authname value.  See
			  the "set authname" command below.

	 COMPILATIONDATE  This is replaced with	the date on which ppp was com-
			  piled.

	 DNS0 &	DNS1	  These	are replaced with the primary and secondary
			  nameserver IP	numbers.  If nameservers are negoti-
			  ated by IPCP,	the values of these macros will
			  change.

	 ENDDISC	  This is replaced with	the local endpoint discrimina-
			  tor value.  See the "set enddisc" command below.

	 HISADDR	  This is replaced with	the peers IP number.

	 HISADDR6	  This is replaced with	the peers IPv6 number.

	 INTERFACE	  This is replaced with	the name of the	interface
			  that's in use.

	 IPOCTETSIN	  This is replaced with	the number of IP bytes re-
			  ceived since the connection was established.

	 IPOCTETSOUT	  This is replaced with	the number of IP bytes sent
			  since	the connection was established.

	 IPPACKETSIN	  This is replaced with	the number of IP packets re-
			  ceived since the connection was established.

	 IPPACKETSOUT	  This is replaced with	the number of IP packets sent
			  since	the connection was established.

	 IPV6OCTETSIN	  This is replaced with	the number of IPv6 bytes re-
			  ceived since the connection was established.

	 IPV6OCTETSOUT	  This is replaced with	the number of IPv6 bytes sent
			  since	the connection was established.

	 IPV6PACKETSIN	  This is replaced with	the number of IPv6 packets re-
			  ceived since the connection was established.

	 IPV6PACKETSOUT	  This is replaced with	the number of IPv6 packets
			  sent since the connection was	established.

	 LABEL		  This is replaced with	the last label name used.  A
			  label	may be specified on the	ppp command line, via
			  the "load" or	"dial" commands	and in the ppp.secret
			  file.

	 MYADDR		  This is replaced with	the IP number assigned to the
			  local	interface.

	 MYADDR6	  This is replaced with	the IPv6 number	assigned to
			  the local interface.

	 OCTETSIN	  This is replaced with	the number of bytes received
			  since	the connection was established.

	 OCTETSOUT	  This is replaced with	the number of bytes sent since
			  the connection was established.

	 PACKETSIN	  This is replaced with	the number of packets received
			  since	the connection was established.

	 PACKETSOUT	  This is replaced with	the number of packets sent
			  since	the connection was established.

	 PEER_ENDDISC	  This is replaced with	the value of the peers end-
			  point	discriminator.

	 PROCESSID	  This is replaced with	the current process id.

	 SOCKNAME	  This is replaced with	the name of the	diagnostic
			  socket.

	 UPTIME		  This is replaced with	the bundle uptime in HH:MM:SS
			  format.

	 USER		  This is replaced with	the username that has been au-
			  thenticated with PAP or CHAP.	 Normally, this	vari-
			  able is assigned only	in -direct mode.  This value
			  is available irrespective of whether utmp logging is
			  enabled.

	 VERSION	  This is replaced with	the current version number of
			  ppp.

	 These substitutions are also done by the "set proctitle", "ident" and
	 "log" commands.

	 If you	wish to	pause ppp while	the command executes, use the "shell"
	 command instead.

     clear physical|ipcp|ipv6 [current|overall|peak...]
	 Clear the specified throughput	values at either the "physical",
	 "ipcp"	or "ipv6cp" level.  If "physical" is specified,	context	must
	 be given (see the "link" command below).  If no second	argument is
	 given,	all values are cleared.

     clone name[,name]...
	 Clone the specified link, creating one	or more	new links according to
	 the name argument(s).	This command must be used from the "link" com-
	 mand below unless you've only got a single link (in which case	that
	 link becomes the default).  Links may be removed using	the "remove"
	 command below.

	 The default link name is "deflink".

     close [lcp|ccp[!]]
	 If no arguments are given, the	relevant protocol layers will be
	 brought down and the link will	be closed.  If "lcp" is	specified, the
	 LCP layer is brought down, but	ppp will not bring the link offline.
	 It is subsequently possible to	use "term" (see	below) to talk to the
	 peer machine if, for example, something like "slirp" is being used.
	 If "ccp" is specified,	only the relevant compression layer is closed.
	 If the	"!" 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 ppp or exit ppp.  See the "quit"
	 command below.

     delete[!] dest
	 This command deletes the route	with the given dest IP address.	 If
	 dest is specified as `ALL', all non-direct entries in the routing ta-
	 ble for the current interface,	and all	`sticky	route' entries are
	 deleted.  If dest is specified	as `default', the default route	is
	 deleted.

	 If the	delete!	command	is used	(note the trailing "!"), ppp will not
	 complain if the route does not	already	exist.

     dial|call [label]...
	 This command is the equivalent	of "load label"	followed by "open",
	 and is	provided for backwards compatibility.

     down [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 `lcp'	is specified, the LCP
	 layer is terminated but the device is not brought offline and the
	 link is not closed.  If `ccp' is specified, only the relevant com-
	 pression layer(s) are terminated.

     help|? [command]
	 Show a	list of	available commands.  If	command	is specified, show the
	 usage string for that command.

     ident [text...]
	 Identify the link to the peer using text.  If text is empty, link
	 identification	is disabled.  It is possible to	use any	of the words
	 described for the bg command above.  Refer to the sendident command
	 for details of	when ppp identifies itself to the peer.

     iface command [args]
	 This command is used to control the interface used by ppp.  Command
	 may be	one of the following:

	 iface add[!] addr[/bits] [peer]

	 iface add[!] addr mask	peer
	     Add the given addr	mask peer combination to the interface.	 In-
	     stead of specifying mask, /bits can be used (with no space	be-
	     tween it and addr).  If the given address already exists, the
	     command fails unless the "!" is used - in which case the previous
	     interface address entry is	overwritten with the new one, allowing
	     a change of netmask or peer address.

	     If	only addr is specified,	bits defaults to "32" and peer de-
	     faults to "255.255.255.255".  This	address	(the broadcast ad-
	     dress) is the only	duplicate peer address that ppp	allows.

	 iface clear [INET | INET6]
	     If	this command is	used while ppp is in the OPENED	state or while
	     in	-auto mode, all	addresses except for the NCP negotiated	ad-
	     dress are deleted from the	interface.  If ppp is not in the
	     OPENED state and is not in	-auto mode, all	interface addresses
	     are deleted.

	     If	the INET or INET6 arguments are	used, only addresses for that
	     address family are	cleared.

	 iface delete[!]|rm[!] addr
	     This command deletes the given addr from the interface.  If the
	     "!" is used, no error is given if the address isn't currently as-
	     signed to the interface (and no deletion takes place).

	 iface show
	     Shows the current state and current addresses for the interface.
	     It	is much	the same as running "ifconfig INTERFACE".

	 iface help [sub-command]
	     This command, when	invoked	without	sub-command, will show a list
	     of	possible "iface" sub-commands and a brief synopsis for each.
	     When invoked with sub-command, only the synopsis for the given
	     sub-command is shown.

     [data]link	name[,name]... command [args]
	 This command may prefix any other command if the user wishes to spec-
	 ify which link	the command should affect.  This is only applicable
	 after multiple	links have been	created	in Multi-link mode using the
	 "clone" command.

	 Name specifies	the name of an existing	link.  If name is a comma sep-
	 arated	list, command is executed on each link.	 If name is "*",
	 command is executed on	all links.

     load [label]...
	 Load the given	label(s) from the ppp.conf file.  If label is not
	 given,	the default label is used.

	 Unless	the label section uses the "set	mode", "open" or "dial"	com-
	 mands,	ppp will not attempt to	make an	immediate connection.

     log word...
	 Send the given	word(s)	to the log file	with the prefix	"LOG:".	 Word
	 substitutions are done	as explained under the "!bg" command above.

     open [lcp|ccp|ipcp]
	 This is the opposite of the "close" command.  All closed links	are
	 immediately brought up	apart from second and subsequent demand-dial
	 links - these will come up based on the "set autoload"	command	that
	 has been used.

	 If the	"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 "open lcp" can be	used to	put them into effect.
	 After renegotiating LCP, any agreed authentication will also take
	 place.

	 If the	"ccp" argument is used,	the relevant compression layer is
	 opened.  Again, if it is already open,	it will	be renegotiated.

	 If the	"ipcp" argument	is used, the link will be brought up as	nor-
	 mal, but if IPCP is already open, it will be renegotiated and the
	 network interface will	be reconfigured.

	 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 is however useful as a way of forcing the CCP or VJ	dictionaries
	 to be reset.

     passwd pass
	 Specify the password required for access to the full ppp command set.
	 This password is required when	connecting to the diagnostic port (see
	 the "set server" command).  Pass is specified on the "set server"
	 command line.	The value of pass is not logged	when command logging
	 is active, instead, the literal string	`********' is logged.

     quit|bye [all]
	 If "quit" is executed from the	controlling connection or from a com-
	 mand file, ppp	will exit after	closing	all connections.  Otherwise,
	 if the	user is	connected to a diagnostic socket, the connection is
	 simply	dropped.

	 If the	all argument is	given, ppp will	exit despite the source	of the
	 command after closing all existing connections.

     remove|rm
	 This command removes the given	link.  It is only really useful	in
	 multi-link mode.  A link must be in the CLOSED	state before it	is re-
	 moved.

     rename|mv name
	 This command renames the given	link to	name.  It will fail if name is
	 already used by another link.

	 The default link name is `deflink'.  Renaming it to `modem', `cuaa0'
	 or `USR' may make the log file	more readable.

     resolv command
	 This command controls ppp's manipulation of the resolv.conf(5)	file.
	 When ppp starts up, it	loads the contents of this file	into memory
	 and retains this image	for future use.	 command is one	of the follow-
	 ing:

	 readonly  Treat /etc/resolv.conf as read only.	 If "dns" is enabled,
		   ppp will still attempt to negotiate nameservers with	the
		   peer, making	the results available via the DNS0 and DNS1
		   macros.  This is the	opposite of the	"resolv	writable" com-
		   mand.

	 reload	   Reload /etc/resolv.conf into	memory.	 This may be necessary
		   if for example a DHCP client	overwrote /etc/resolv.conf.

	 restore   Replace /etc/resolv.conf with the version originally	read
		   at startup or with the last "resolv reload" command.	 This
		   is sometimes	a useful command to put	in the
		   /etc/ppp/ppp.linkdown file.

	 rewrite   Rewrite the /etc/resolv.conf	file.  This command will work
		   even	if the "resolv readonly" command has been used.	 It
		   may be useful as a command in the /etc/ppp/ppp.linkup file
		   if you wish to defer	updating /etc/resolv.conf until	after
		   other commands have finished.

	 writable  Allow ppp to	update /etc/resolv.conf	if "dns" is enabled
		   and ppp successfully	negotiates a DNS.  This	is the oppo-
		   site	of the "resolv readonly" command.

     save
	 This option is	not (yet) implemented.

     sendident
	 This command tells ppp	to identify itself to the peer.	 The link must
	 be in LCP state or higher.  If	no identity has	been set (via the
	 ident command), sendident will	fail.

	 When an identity has been set,	ppp will automatically identify	itself
	 when it sends or receives a configure reject, when negotiation	fails
	 or when LCP reaches the opened	state.

	 Received identification packets are logged to the LCP log (see	set
	 log for details) and are never	responded to.

     set[up] var value
	 This option allows the	setting	of any of the following	variables:

	 set accmap 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).

	     For the XON/XOFF scenario,	use "set accmap	000a0000".

	 set [auth]key value
	     This sets the authentication key (or password) used in client
	     mode PAP or CHAP negotiation to the given value.  It also speci-
	     fies the password to be used in the dial or login scripts in
	     place of the `\P' sequence, preventing the	actual password	from
	     being logged.  If command or chat logging is in effect, value is
	     logged as `********' for security reasons.

	     If	the first character of value is	an exclamation mark ("!"), ppp
	     treats the	remainder of the string	as a program that must be exe-
	     cuted to determine	the "authname" and "authkey" values.

	     If	the "!"	is doubled up (to "!!"), it is treated as a single
	     literal "!", otherwise, ignoring the "!", value is	parsed as a
	     program to	execute	in the same was	as the "!bg" command above,
	     substituting special names	in the same manner.  Once executed,
	     ppp will feed the program three lines of input, each terminated
	     by	a newline character:

	     +o	 The host name as sent in the CHAP challenge.

	     +o	 The challenge string as sent in the CHAP challenge.

	     +o	 The locally defined "authname".

	     Two lines of output are expected:

	     +o	 The "authname"	to be sent with	the CHAP response.

	     +o	 The "authkey",	which is encrypted with	the challenge and re-
		 quest id, the answer being sent in the	CHAP response packet.

	     When configuring ppp in this manner, it's expected	that the host
	     challenge is a series of ASCII digits or characters.  An encryp-
	     tion device or Secure ID card is usually required to calculate
	     the secret	appropriate for	the given challenge.

	 set authname id
	     This sets the authentication id used in client mode PAP or	CHAP
	     negotiation.

	     If	used in	-direct	mode with CHAP enabled,	id is used in the ini-
	     tial authentication challenge and should normally be set to the
	     local machine name.

	 set autoload min-percent max-percent period
	     These settings apply only in multi-link mode and default to zero,
	     zero and five respectively.  When more than one demand-dial (also
	     known as -auto) mode link is available, only the first link is
	     made active when ppp first	reads data from	the tun	device.	 The
	     next demand-dial link will	be opened only when the	current	bundle
	     throughput	is at least max-percent	percent	of the total bundle
	     bandwidth for period seconds.  When the current bundle throughput
	     decreases to min-percent percent or less of the total bundle
	     bandwidth for period seconds, a demand-dial link will be brought
	     down as long as it's not the last active link.

	     Bundle throughput is measured as the maximum of inbound and out-
	     bound traffic.

	     The default values	cause demand-dial links	to simply come up one
	     at	a time.

	     Certain devices cannot determine their physical bandwidth,	so it
	     is	sometimes necessary to use the "set bandwidth" command (de-
	     scribed below) to make "set autoload" work	correctly.

	 set bandwidth value
	     This command sets the connection bandwidth	in bits	per second.
	     value must	be greater than	zero.  It is currently only used by
	     the "set autoload"	command	above.

	 set callback option...
	     If	no arguments are given,	callback is disabled, otherwise, ppp
	     will request (or in -direct mode, will accept) one	of the given
	     options.  In client mode, if an option is NAK'd ppp will request
	     a different option, until no options remain at which point	ppp
	     will terminate negotiations (unless "none"	is one of the speci-
	     fied option).  In server mode, ppp	will accept any	of the given
	     protocols - but the client	must request one of them.  If you wish
	     callback to be optional, you must include none as an option.

	     The options are as	follows	(in this order of preference):

	     auth    The callee	is expected to decide the callback number
		     based on authentication.  If ppp is the callee, the num-
		     ber should	be specified as	the fifth field	of the peers
		     entry in /etc/ppp/ppp.secret.

	     cbcp    Microsoft's callback control protocol is used.  See "set
		     cbcp" below.

		     If	you wish to negotiate cbcp in client mode but also
		     wish to allow the server to request no callback at	CBCP
		     negotiation time, you must	specify	both cbcp and none as
		     callback options.

	     E.164 *|number[,number]...
		     The caller	specifies the number.  If ppp is the callee,
		     number should be either a comma separated list of allow-
		     able numbers or a "*", meaning any	number is permitted.
		     If	ppp is the caller, only	a single number	should be
		     specified.

		     Note, this	option is very unsafe when used	with a "*" as
		     a malicious caller	can tell ppp to	call any (possibly in-
		     ternational) number without first authenticating them-
		     selves.

	     none    If	the peer does not wish to do callback at all, ppp will
		     accept the	fact and continue without callback rather than
		     terminating the connection.  This is required (in addi-
		     tion to one or more other callback	options) if you	wish
		     callback to be optional.

	 set cbcp [*|number[,number...]	[delay [retry]]]
	     If	no arguments are given,	CBCP (Microsoft's CallBack Control
	     Protocol) is disabled - ie, configuring CBCP in the "set
	     callback" command will result in ppp requesting no	callback in
	     the CBCP phase.  Otherwise, ppp attempts to use the given phone
	     number(s).

	     In	server mode (-direct), ppp will	insist that the	client uses
	     one of these numbers, unless "*" is used in which case the	client
	     is	expected to specify the	number.

	     In	client mode, ppp will attempt to use one of the	given numbers
	     (whichever	it finds to be agreeable with the peer), or if "*" is
	     specified,	ppp will expect	the peer to specify the	number.

	 set cd	[off|seconds[!]]
	     Normally, ppp checks for the existence of carrier depending on
	     the type of device	that has been opened:

		Terminal Devices
		     Carrier is	checked	one second after the login script is
		     complete.	If it's	not set, ppp assumes that this is be-
		     cause the device doesn't support carrier (which is	true
		     for most "laplink"	NULL-modem cables), logs the fact and
		     stops checking for	carrier.

		     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.

		ISDN (i4b) Devices
		     Carrier is	checked	once per second	for 6 seconds.	If
		     it's not set after	the sixth second, the connection at-
		     tempt is considered to have failed	and the	device is
		     closed.  Carrier is always	required for i4b devices.

		PPPoE (netgraph) Devices
		     Carrier is	checked	once per second	for 5 seconds.	If
		     it's not set after	the fifth second, the connection at-
		     tempt is considered to have failed	and the	device is
		     closed.  Carrier is always	required for PPPoE devices.

	     All other device types don't support carrier.  Setting a carrier
	     value will	result in a warning when the device is opened.

	     Some modems take more than	one second after connecting to assert
	     the carrier signal.  If this delay	isn't increased, this will re-
	     sult in ppp's inability to	detect when the	link is	dropped, as
	     ppp assumes that the device isn't asserting carrier.

	     The "set cd" command overrides the	default	carrier	behaviour.
	     seconds specifies the maximum number of seconds that ppp should
	     wait after	the dial script	has finished before deciding if	car-
	     rier is available or not.

	     If	"off" is specified, ppp	will not check for carrier on the de-
	     vice, otherwise ppp will not proceed to the login script until
	     either carrier is detected	or until seconds has elapsed, at which
	     point ppp assumes that the	device will not	set carrier.

	     If	no arguments are given,	carrier	settings will go back to their
	     default values.

	     If	seconds	is followed immediately	by an exclamation mark ("!"),
	     ppp will require carrier.	If carrier is not detected after
	     seconds seconds, the link will be disconnected.

	 set choked [timeout]
	     This sets the number of seconds that ppp will keep	a choked out-
	     put queue before dropping all pending output packets.  If timeout
	     is	less than or equal to zero or if timeout isn't specified, it
	     is	set to the default value of 120	seconds.

	     A choked output queue occurs when ppp 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.).	 ppp
	     will not read packets indefinitely.  Instead, it reads up to 30
	     packets (or 30 + nlinks * 2 packets in multi-link mode), then
	     stops reading the network interface until either timeout seconds
	     have passed or at least one packet	has been sent.

	     If	timeout	seconds	pass, all pending output packets are dropped.

	 set ctsrts|crtscts on|off
	     This sets hardware	flow control.  Hardware	flow control is	on by
	     default.

	 set deflate out-winsize [in-winsize]
	     This sets the DEFLATE algorithms default outgoing and incoming
	     window sizes.  Both out-winsize and in-winsize must be values be-
	     tween 8 and 15.  If in-winsize is specified, ppp will insist that
	     this window size is used and will not accept any other values
	     from the peer.

	 set dns [primary [secondary]]
	     This command specifies DNS	overrides for the "accept dns" com-
	     mand.  Refer to the "accept" command description above for	de-
	     tails.  This command does not affect the IP numbers requested us-
	     ing "enable dns".

	 set device|line value...
	     This sets the device(s) to	which ppp will talk to the given
	     "value".

	     All ISDN and serial device	names are expected to begin with
	     /dev/.  ISDN devices are usually called i4brbchX and serial de-
	     vices are usually called cuaXX.

	     If	"value"	does not begin with /dev/, it must either begin	with
	     an	exclamation mark ("!"),	be of the format
	     PPPoE:iface[:provider] (on	netgraph(4) enabled systems), or be of
	     the format	host:port[/tcp|udp].

	     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 ppp and are read and written as if they were a	regu-
	     lar device.

	     If	a PPPoE:iface[:provider] specification is given, ppp will at-
	     tempt to create a PPP over	Ethernet connection using the given
	     iface interface by	using netgraph(4).  If netgraph(4) is not
	     available,	ppp will attempt to load it using kldload(2).  If this
	     fails, an external	program	must be	used such as the pppoed(8)
	     program available under OpenBSD.  The given 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.

	     When a PPPoE connection is	established, ppp will place the	name
	     of	the Access Concentrator	in the environment variable ACNAME.

	     Refer to netgraph(4) and ng_pppoe(4) for further details.

	     If	a host:port[/tcp|udp] specification is given, ppp will attempt
	     to	connect	to the given host on the given port.  If a "/tcp" or
	     "/udp" suffix is not provided, the	default	is "/tcp".  Refer to
	     the section on PPP	OVER TCP and UDP above for further details.

	     If	multiple "values" are specified, ppp will attempt to open each
	     one in turn until it succeeds or runs out of devices.

	 set dial chat-script
	     This specifies the	chat script that will be used to dial the
	     other side.  See also the "set login" command below.  Refer to
	     chat(8) and to the	example	configuration files for	details	of the
	     chat script format.  It is	possible to specify some special
	     `values' in your chat script as follows:

	     \c	 When used as the last character in a `send' string, this in-
		 dicates that a	newline	should not be appended.

	     \d	 When the chat script encounters this sequence,	it delays two
		 seconds.

	     \p	 When the chat script encounters this sequence,	it delays for
		 one quarter of	a second.

	     \n	 This is replaced with a newline character.

	     \r	 This is replaced with a carriage return character.

	     \s	 This is replaced with a space character.

	     \t	 This is replaced with a tab character.

	     \T	 This is replaced by the current phone number (see "set	phone"
		 below).

	     \P	 This is replaced by the current authkey value (see "set
		 authkey" above).

	     \U	 This is replaced by the current authname value	(see "set
		 authname" above).

	     Note that two parsers will	examine	these escape sequences,	so in
	     order to have the `chat parser' see the escape character, it is
	     necessary to escape it from the `command parser'.	This means
	     that in practice you should use two escapes, for example:

		   set dial "... ATDT\\T CONNECT"

	     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 ("!").  If a	literal	exclamation
	     mark is required, double it up to "!!" and	it will	be treated as
	     a single literal "!".  When the command is	executed, standard in-
	     put and standard output are directed to the open device (see the
	     "set device" command), and	standard error is read by ppp and sub-
	     stituted as the expect or send string.  If	ppp is running in in-
	     teractive mode, file descriptor 3 is attached to /dev/tty.

	     For example (wrapped for readability):

		   set login "TIMEOUT 5	\"\" \"\" login:--login: ppp \
		   word: ppp \"!sh \\-c	\\\"echo \\-n label: >&2\\\"\" \
		   \"!/bin/echo	in\" HELLO"

	     would result in the following chat	sequence (output using the
	     `set log local chat' command before dialing):

		   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!

	     Note (again) the use of the escape	character, allowing many lev-
	     els 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 "-" signs are	escaped, oth-
	     erwise this parser	will see them as constituting an expect-send-
	     expect sequence.  When the	"!" character is seen, the execution
	     parser reads the first command as three arguments,	and then sh(1)
	     itself expands the	argument after the -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 ppp itself sends and
	     logs it, and in the second	example, we just output	to stdout,
	     which is attached directly	to the modem.

	     This, of course means that	it is possible to execute an entirely
	     external "chat" command rather than using the internal one.  See
	     chat(8) for a good	alternative.

	     The external command that is executed is subjected	to the same
	     special word expansions as	the "!bg" command.

	 set enddisc [label|IP|MAC|magic|psn value]
	     This command sets our local endpoint discriminator.  If set prior
	     to	LCP negotiation, and if	no "disable enddisc" command has been
	     used, ppp will send the information to the	peer using the LCP
	     endpoint discriminator option.  The following discriminators may
	     be	set:

	     label   The current label is used.

	     IP	     Our local IP number is used.  As LCP is negotiated	prior
		     to	IPCP, it is possible that the IPCP layer will subse-
		     quently change this value.	 If it does, the endpoint dis-
		     criminator	stays at the old value unless manually reset.

	     MAC     This is similar to	the 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.

		     As	the local IP number defaults to	whatever the machine
		     host name is, "set	enddisc	mac" is	usually	done prior to
		     any "set ifaddr" commands.

	     magic   A 20 digit	random number is used.	Care should be taken
		     when using	magic numbers as restarting ppp	or creating a
		     link using	a different ppp	invocation will	also use a
		     different magic number and	will therefore not be recog-
		     nised by the peer as belonging to the same	bundle.	 This
		     makes it unsuitable for -direct connections.

	     psn value
		     The given value is	used.  Value should be set to an abso-
		     lute public switched network number with the country code
		     first.

	     If	no arguments are given,	the endpoint discriminator is reset.

	 set escape value...
	     This option is similar to the "set	accmap"	option above.  It al-
	     lows the user to specify a	set of characters that will be
	     `escaped' as they travel across the link.

	 set filter dial|alive|in|out rule-no permit|deny|clear|rule-no	[!]
	     [[host] src_addr[/width] [dst_addr[/width]]] [proto [src lt|eq|gt
	     port] [dst	lt|eq|gt port] [estab] [syn] [finrst] [timeout secs]]
	     ppp supports four filter sets.  The alive filter specifies	pack-
	     ets that keep the connection alive	- resetting the	idle timer.
	     The dial filter specifies packets that cause ppp to dial when in
	     -auto mode.  The in filter	specifies packets that are allowed to
	     travel into the machine and the out filter	specifies packets that
	     are allowed out of	the machine.

	     Filtering is done prior to	any IP alterations that	might be done
	     by	the NAT	engine on outgoing packets and after any IP alter-
	     ations 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 rule-no (unless skipped
	     by	specifying a rule number as the	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 in and out
	     filters, this means that the packet is dropped.  In the case of
	     alive filters it means that the packet will not reset the idle
	     timer (even if the	in/out filter has a "timeout" value) and in
	     the case of dial filters it means that the	packet will not	trig-
	     ger a dial.  A packet failing to trigger a	dial will be dropped
	     rather than queued.  Refer	to the section on PACKET FILTERING
	     above for further details.

	 set hangup chat-script
	     This specifies the	chat script that will be used to reset the de-
	     vice before it is closed.	It should not normally be necessary,
	     but can be	used for devices that fail to reset themselves prop-
	     erly on close.

	 set help|? [command]
	     This command gives	a summary of available set commands, or	if
	     command is	specified, the command usage is	shown.

	 set ifaddr [myaddr[/nn] [hisaddr[/nn] [netmask	[triggeraddr]]]]
	     This command specifies the	IP addresses that will be used during
	     IPCP negotiation.	Addresses are specified	using the format

		   a.b.c.d/nn

	     Where "a.b.c.d" is	the preferred IP, but nn specifies how many
	     bits of the address we will insist	on.  If	/nn is omitted,	it de-
	     faults to "/32" unless the	IP address is 0.0.0.0 in which case it
	     defaults to "/0".

	     If	you wish to assign a dynamic IP	number to the peer, hisaddr
	     may also be specified as a	range of IP numbers in the format

		   IP[-IP][,IP[-IP]]...

	     for example:

		   set ifaddr 10.0.0.1 10.0.1.2-10.0.1.10,10.0.1.20

	     will only negotiate "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, ppp 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).

	     If	the peer requests an IP	number that's either outside of	this
	     range or is already in use, ppp will suggest a random unused IP
	     number from the range.

	     If	triggeraddr is specified, it is	used in	place of myaddr	in the
	     initial IPCP negotiation.	However, only an address in the	myaddr
	     range will	be accepted.  This is useful when negotiating with
	     some PPP implementations that will	not assign an IP number	unless
	     their peer	requests "0.0.0.0".

	     It	should be noted	that in	-auto mode, ppp	will configure the in-
	     terface immediately upon reading the "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.

	     Note that the HISADDR argument may	be overridden by the third
	     field in the ppp.secret file once the client has authenticated
	     itself (if	PAP or CHAP are	"enabled").  Refer to the
	     AUTHENTICATING INCOMING CONNECTIONS section for details.

	     In	all cases, if the interface is already configured, ppp will
	     try to maintain the interface IP numbers so that any existing
	     bound sockets will	remain valid.

	 set ifqueue packets
	     Set the maximum number of packets that ppp	will read from the
	     tunnel interface while data cannot	be sent	to any of the avail-
	     able links.  This queue limit is necessary	to flow	control	outgo-
	     ing data as the tunnel interface is likely	to be far faster than
	     the combined links	available to ppp.

	     If	packets	is set to a value less than the	number of links, ppp
	     will read up to that value	regardless.  This prevents any possi-
	     ble latency problems.

	     The default value for packets is "30".

	 set ccpretry|ccpretries [timeout [reqtries [trmtries]]]

	 set chapretry|chapretries [timeout [reqtries]]

	 set ipcpretry|ipcpretries [timeout [reqtries [trmtries]]]

	 set ipv6cpretry|ipv6cpretries [timeout	[reqtries [trmtries]]]

	 set lcpretry|lcpretries [timeout [reqtries [trmtries]]]

	 set papretry|papretries [timeout [reqtries]]
	     These commands set	the number of seconds that ppp will wait be-
	     fore resending Finite State Machine (FSM) Request packets.	 The
	     default timeout for all FSMs is 3 seconds (which should suffice
	     in	most cases).

	     If	reqtries is specified, it tells	ppp how	many configuration re-
	     quest 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.

	     If	trmtries is specified, it tells	ppp how	many terminate re-
	     quests should be sent before giving up waiting for	the peers re-
	     sponse.  The default is 3 attempts.  Authentication protocols are
	     not terminated and	it is therefore	invalid	to specify trmtries
	     for PAP or	CHAP.

	     In	order to avoid negotiations with the peer that will never con-
	     verge, ppp	will only send at most 3 times the configured number
	     of	reqtries in any	given negotiation session before giving	up and
	     closing that layer.

	 set log [local] [+|-]value...
	     This command allows the adjustment	of the current log level.  Re-
	     fer to the	Logging	Facility section for further details.

	 set login chat-script
	     This chat-script compliments the dial-script.  If both are	speci-
	     fied, the login script will be executed after the dial script.
	     Escape sequences available	in the dial script are also available
	     here.

	 set logout chat-script
	     This specifies the	chat script that will be used to logout	before
	     the hangup	script is called.  It should not normally be neces-
	     sary.

	 set lqrperiod|echoperiod frequency
	     This command sets the frequency in	seconds	at which LQR or	LCP
	     ECHO packets are sent.  The default is 30 seconds.	 You must also
	     use the "enable lqr" and/or "enable echo" commands	if you wish to
	     send LQR or LCP ECHO requests to the peer.

	 set mode interactive|auto|ddial|background
	     This command allows you to	change the `mode' of the specified
	     link.  This is normally only useful in multi-link mode, but may
	     also be used in uni-link mode.

	     It	is not possible	to change a link that is `direct' or
	     `dedicated'.

	     Note: If you issue	the command "set mode auto", and have network
	     address translation enabled, it may be useful to "enable
	     iface-alias" afterwards.  This will allow ppp to do the necessary
	     address translations to enable the	process	that triggers the con-
	     nection to	connect	once the link is up despite the	peer assigning
	     us	a new (dynamic)	IP address.

	 set mppe [40|56|128|* [stateless|stateful|*]]
	     This option selects the encryption	parameters used	when negotia-
	     tion MPPE.	 MPPE can be disabled entirely with the	"disable mppe"
	     command.  If no arguments are given, ppp will attempt to negoti-
	     ate a stateful link with a	128 bit	key, but will agree to what-
	     ever the peer requests (including no encryption at	all).

	     If	any arguments are given, ppp will insist on using MPPE and
	     will close	the link if it's rejected by the peer (Note; this be-
	     haviour can be overridden by a configured RADIUS server).

	     The first argument	specifies the number of	bits that ppp should
	     insist on during negotiations and the second specifies whether
	     ppp 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-ini-
	     tialised every 256	packets	or after the loss of any data and the
	     key is changed every 256 packets.	Stateless mode is less effi-
	     cient but is better for unreliable	transport layers.

	 set mrru [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.

	 set mru [max[imum]] [value]
	     The default MRU (Maximum Receive Unit) is 1500.  If it is in-
	     creased, the other	side *may* increase its	MTU.  In theory	there
	     is	no point in decreasing the MRU to below	the default as the PPP
	     protocol says implementations *must* be able to accept packets of
	     at	least 1500 octets.

	     If	the "maximum" keyword is used, ppp will	refuse to negotiate a
	     higher value.  The	maximum	MRU can	be set to 2048 at most.	 Set-
	     ting a maximum of less than 1500 violates the PPP rfc, but	may
	     sometimes be necessary.  For example, PPPoE imposes a maximum of
	     1492 due to hardware limitations.

	     If	no argument is given, 1500 is assumed.	A value	must be	given
	     when "maximum" is specified.

	 set mtu [max[imum]] [value]
	     The default MTU is	1500.  At negotiation time, ppp	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,
	     ppp will not accept MRU values less than value.  When negotia-
	     tions are complete, the MTU is used when writing to the inter-
	     face, 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).

	     If	the "maximum" keyword is used, ppp will	refuse to negotiate a
	     higher value.  The	maximum	MTU can	be set to 2048 at most.	 Note,
	     it	is necessary to	use the	"maximum" keyword to limit the MTU
	     when using	PPPoE.

	     If	no value is given, 1500, or whatever the peer asks for is
	     used.  A value must be given when "maximum" is specified.

	 set nbns [x.x.x.x [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,	ppp will reject	any such requests.

	 set openmode active|passive [delay]
	     By	default, openmode is always active with	a one second delay.
	     That is, ppp 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 passive.  If you
	     want to initiate negotiations immediately or after	more than one
	     second, the appropriate delay may be specified here in seconds.

	 set parity odd|even|none|mark
	     This allows the line parity to be set.  The default value is
	     none.

	 set phone telno[|backupnumber]...[:nextnumber]...
	     This allows the specification of the phone	number to be used in
	     place of the \\T string in	the dial and login chat	scripts.  Mul-
	     tiple phone numbers may be	given separated	either by a pipe ("|")
	     or	a colon	(":").

	     Numbers after the pipe are	only dialed if the dial	or login
	     script for	the previous number failed.

	     Numbers after the colon are tried sequentially, irrespective of
	     the reason	the line was dropped.

	     If	multiple numbers are given, ppp	will dial them according to
	     these rules until a connection is made, retrying the maximum num-
	     ber of times specified by "set redial" below.  In -background
	     mode, each	number is attempted at most once.

	 set pppoe [standard|3Com]
	     This option configures the	underlying ng_pppoe(4) node to either
	     standard RFC2516 PPPoE or proprietary 3Com	mode.  If not set the
	     system default will be used.

	 set [proc]title [value]
	     The current process title as displayed by ps(1) is	changed	ac-
	     cording to	value.	If value is not	specified, the original
	     process title is restored.	 All the word replacements done	by the
	     shell commands (see the "bg" command above) are done here too.

	     Note, if USER is required in the process title, the "set
	     proctitle"	command	must appear in ppp.linkup, as it is not	known
	     when the commands in ppp.conf are executed.

	 set radius [config-file]
	     This command enables RADIUS support (if it's compiled in).
	     config-file refers	to the radius client configuration file	as de-
	     scribed in	radius.conf(5).	 If PAP, CHAP, MSCHAP or MSCHAPv2 are
	     "enabled",	ppp behaves as a Network Access	Server and uses	the
	     configured	RADIUS server to authenticate rather than authenticat-
	     ing from the ppp.secret file or from the passwd database.

	     If	none of	PAP, CHAP, MSCHAP or MSCHAPv2 are enabled, "set
	     radius" will do nothing.

	     ppp uses the following attributes from the	RADIUS reply:

		RAD_FRAMED_IP_ADDRESS
		     The peer IP address is set	to the given value.

		RAD_FRAMED_IP_NETMASK
		     The tun interface netmask is set to the given value.

		RAD_FRAMED_MTU
		     If	the given MTU is less than the peers MRU as agreed
		     during LCP	negotiation, *and* it is less that any config-
		     ured MTU (see the "set mru" command), the tun interface
		     MTU is set	to the given value.

		RAD_FRAMED_COMPRESSION
		     If	the received compression type is "1", ppp will request
		     VJ	compression during IPCP	negotiations despite any
		     "disable vj" configuration	command.

		RAD_FILTER_ID
		     If	this attribute is supplied, ppp	will attempt to	use it
		     as	an additional label to load from the ppp.linkup	and
		     ppp.linkdown files.  The load will	be attempted before
		     (and in addition to) the normal label search.  If the la-
		     bel doesn't exist,	no action is taken and ppp proceeds to
		     the normal	load using the current label.

		RAD_FRAMED_ROUTE
		     The received string is expected to	be in the format
		     dest[/bits] gw [metrics].	Any specified metrics are ig-
		     nored.  MYADDR and	HISADDR	are understood as valid	values
		     for dest and gw, "default"	can be used for	dest to	sep-
		     cify the default route, and "0.0.0.0" is understood to be
		     the same as "default" for dest and	HISADDR	for gw.

		     For example, a returned value of "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 HISADDR and	a returned value of
		     "0.0.0.0 0.0.0.0" or "default HISADDR" would result in a
		     default route to HISADDR.

		     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 MYADDR	or HISADDR keywords.

		RAD_FRAMED_IPV6_PREFIX
		     If	this attribute is supplied, the	value is substituted
		     for IPV6PREFIX in a command.  You may pass	it to such as
		     DHCPv6 for	delegating an IPv6 prefix to a peer.

		RAD_FRAMED_IPV6_ROUTE
		     The received string is expected to	be in the format
		     dest[/bits] gw [metrics].	Any specified metrics are ig-
		     nored.  MYADDR6 and HISADDR6 are understood as valid val-
		     ues for dest and gw, "default" can	be used	for dest to
		     sepcify the default route,	and "::" is understood to be
		     the same as "default" for dest and	HISADDR6 for gw.

		     For example, a returned value of "3ffe:505:abcd::/48 ::"
		     would result in a routing table entry to the
		     3ffe:505:abcd::/48	network	via HISADDR6 and a returned
		     value of ":: ::" or "default HISADDR6" would result in a
		     default route to HISADDR6.

		     All RADIUS	IPv6 routes are	applied	after any sticky
		     routes are	applied, making	RADIUS IPv6 routes override
		     configured	routes.	 This also applies for RADIUS IPv6
		     routes that don't include the MYADDR6 or HISADDR6 key-
		     words.

		RAD_SESSION_TIMEOUT
		     If	supplied, the client connection	is closed after	the
		     given number of seconds.

		RAD_REPLY_MESSAGE
		     If	supplied, this message is passed back to the peer as
		     the authentication	SUCCESS	text.

		RAD_MICROSOFT_MS_CHAP_ERROR
		     If	this RAD_VENDOR_MICROSOFT vendor specific attribute is
		     supplied, it is passed back to the	peer as	the authenti-
		     cation FAILURE text.

		RAD_MICROSOFT_MS_CHAP2_SUCCESS
		     If	this RAD_VENDOR_MICROSOFT vendor specific attribute is
		     supplied and if MS-CHAPv2 authentication is being used,
		     it	is passed back to the peer as the authentication SUC-
		     CESS text.

		RAD_MICROSOFT_MS_MPPE_ENCRYPTION_POLICY
		     If	this RAD_VENDOR_MICROSOFT vendor specific attribute is
		     supplied and has a	value of 2 (Required), ppp will	insist
		     that MPPE encryption is used (even	if no "set mppe" con-
		     figuration	command	has been given with arguments).	 If it
		     is	supplied with a	value of 1 (Allowed), encryption is
		     made optional (despite any	"set mppe" configuration com-
		     mands with	arguments).

		RAD_MICROSOFT_MS_MPPE_ENCRYPTION_TYPES
		     If	this RAD_VENDOR_MICROSOFT vendor specific attribute is
		     supplied, bits 1 and 2 are	examined.  If either or	both
		     are set, 40 bit and/or 128	bit (respectively) encryption
		     options are set, overriding any given first argument to
		     the "set mppe" command.  Note, it is not currently	possi-
		     ble for the RADIUS	server to specify 56 bit encryption.

		RAD_MICROSOFT_MS_MPPE_RECV_KEY
		     If	this RAD_VENDOR_MICROSOFT vendor specific attribute is
		     supplied, it's value is used as the master	key for	de-
		     cryption of incoming data.	 When clients are authenti-
		     cated using MSCHAPv2, the RADIUS server MUST provide this
		     attribute if inbound MPPE is to function.

		RAD_MICROSOFT_MS_MPPE_SEND_KEY
		     If	this RAD_VENDOR_MICROSOFT vendor specific attribute is
		     supplied, it's value is used as the master	key for	en-
		     cryption of outgoing data.	 When clients are authenti-
		     cated using MSCHAPv2, the RADIUS server MUST provide this
		     attribute if outbound MPPE	is to function.

	     Values received from the RADIUS server may	be viewed using	"show
	     bundle".

	 set rad_alive timeout
	     When RADIUS is configured,	setting	"rad_alive" to a non-zero
	     timeout value will	tell ppp to sent RADIUS	accounting information
	     to	the RADIUS server every	timeout	seconds.

	 set reconnect timeout ntries
	     Should the	line drop unexpectedly (due to loss of CD or LQR fail-
	     ure), a connection	will be	re-established after the given
	     timeout.  The line	will be	re-connected at	most ntries times.
	     Ntries defaults to	zero.  A value of random for timeout will re-
	     sult in a variable	pause, somewhere between 1 and 30 seconds.

	 set recvpipe [value]
	     This sets the routing table RECVPIPE value.  The optimum value is
	     just over twice the MTU value.  If	value is unspecified or	zero,
	     the default kernel	controlled value is used.

	 set redial secs[+inc[-max]][.next] [attempts]
	     ppp can be	instructed to attempt to redial	attempts times.	 If
	     more than one phone number	is specified (see "set phone" above),
	     a pause of	next is	taken before dialing each number.  A pause of
	     secs is taken before starting at the first	number again.  A lit-
	     eral value	of "random" may	be used	here in	place of secs and
	     next, causing a random delay of between 1 and 30 seconds.

	     If	inc is specified, its value is added onto secs each time ppp
	     tries a new number.  secs will only be incremented	at most	max
	     times.  max defaults to 10.

	     Note, the secs delay will be effective, even after	attempts has
	     been exceeded, so an immediate manual dial	may appear to have
	     done nothing.  If an immediate dial is required, a	"!" should im-
	     mediately follow the "open" keyword.  See the "open" description
	     above for further details.

	 set sendpipe [value]
	     This sets the routing table SENDPIPE value.  The optimum value is
	     just over twice the MTU value.  If	value is unspecified or	zero,
	     the default kernel	controlled value is used.

	 set server|socket TcpPort|LocalName|none|open|closed [password
	     [mask]]
	     This command tells	ppp to listen on the given socket or
	     `diagnostic port' for incoming command connections.

	     The word "none" instructs ppp to close any	existing socket	and
	     clear the socket configuration.  The word "open" instructs	ppp to
	     attempt to	re-open	the port.  The word "closed" instructs ppp to
	     close the open port.

	     If	you wish to specify a local domain socket, 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 umask(2)
	     for umask details.	 Refer to services(5) for details of how to
	     translate TCP port	names.

	     You must also specify the password	that must be entered by	the
	     client (using the "passwd"	variable above)	when connecting	to
	     this socket.  If the password is specified	as an empty string, no
	     password is required for connecting clients.

	     When specifying a local domain socket, the	first "%d" sequence
	     found in the socket name will be replaced with the	current	inter-
	     face unit number.	This is	useful when you	wish to	use the	same
	     profile for more than one connection.

	     In	a similar manner TCP sockets may be prefixed with the "+"
	     character,	in which case the current interface unit number	is
	     added to the port number.

	     When using	ppp with a server socket, the pppctl(8)	command	is the
	     preferred mechanism of communications.  Currently,	telnet(1) can
	     also be used, but link encryption may be implemented in the fu-
	     ture, so telnet(1)	should be avoided.

	     Note; SIGUSR1 and SIGUSR2 interact	with the diagnostic socket.

	 set speed value
	     This sets the speed of the	serial device.	If speed is specified
	     as	"sync",	ppp treats the device as a synchronous device.

	     Certain device types will know whether they should	be specified
	     as	synchronous or asynchronous.  These devices will override in-
	     correct settings and log a	warning	to this	effect.

	 set stopped [LCPseconds [CCPseconds]]
	     If	this option is set, ppp	will time out after the	given FSM (Fi-
	     nite State	Machine) has been in the stopped state for the given
	     number of "seconds".  This	option may be useful if	the peer sends
	     a terminate request, but never actually closes the	connection de-
	     spite our sending a terminate acknowledgement.  This is also use-
	     ful if you	wish to	"set openmode passive" and time	out if the
	     peer doesn't send a Configure Request within the given time.  Use
	     "set log +lcp +ccp" to make ppp log the appropriate state transi-
	     tions.

	     The default value is zero,	where ppp doesn't time out in the
	     stopped state.

	     This value	should not be set to less than the openmode delay (see
	     "set openmode" above).

	 set timeout idleseconds [mintimeout]
	     This command allows the setting of	the idle timer.	 Refer to the
	     section titled SETTING THE	IDLE TIMER for further details.

	     If	mintimeout is specified, ppp will never	idle out before	the
	     link has been up for at least that	number of seconds.

	 set urgent [tcp|udp|none] [[+|-]port] ...
	     This command controls the ports that ppp prioritizes when trans-
	     mitting 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 services(5) for details.

	     If	neither	"tcp" or "udp" are specified, "tcp" is assumed.

	     If	no ports are given, the	priority port lists are	cleared	(al-
	     though if "tcp" or	"udp" is specified, only that list is
	     cleared).	If the first port argument is prefixed with a plus
	     ("+") or a	minus ("-"), the current list is adjusted, otherwise
	     the list is reassigned.  ports prefixed with a plus or not	pre-
	     fixed at all are added to the list	and ports prefixed with	a mi-
	     nus are removed from the list.

	     If	"none" is specified, all priority port lists are disabled and
	     even IPTOS_LOWDELAY packets are not prioritised.

	 set vj	slotcomp on|off
	     This command tells	ppp whether it should attempt to negotiate VJ
	     slot compression.	By default, slot compression is	turned on.

	 set vj	slots nslots
	     This command sets the initial number of slots that	ppp will try
	     to	negotiate with the peer	when VJ	compression is enabled (see
	     the `enable' command above).  It defaults to a value of 16.
	     Nslots must be between 4 and 16 inclusive.

     shell|! [command]
	 If command is not specified a shell is	invoked	according to the SHELL
	 environment variable.	Otherwise, the given command is	executed.
	 Word replacement is done in the same way as for the "!bg" command as
	 described above.

	 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; ppp will not continue running until this process has ex-
	 ited.	Use the	bg command if you wish processing to happen in the
	 background.

     show var
	 This command allows the user to examine the following:

	 show bundle
	     Show the current bundle settings.

	 show ccp
	     Show the current CCP compression statistics.

	 show compress
	     Show the current VJ compression statistics.

	 show escape
	     Show the current escape characters.

	 show filter [name]
	     List the current rules for	the given filter.  If name is not
	     specified,	all filters are	shown.

	 show hdlc
	     Show the current HDLC statistics.

	 show help|?
	     Give a summary of available show commands.

	 show iface
	     Show the current interface	information (the same as "iface
	     show").

	 show ipcp
	     Show the current IPCP statistics.

	 show layers
	     Show the protocol layers currently	in use.

	 show lcp
	     Show the current LCP statistics.

	 show [data]link
	     Show high level link information.

	 show links
	     Show a list of available logical links.

	 show log
	     Show the current log values.

	 show mem
	     Show current memory statistics.

	 show ncp
	     Show the current NCP statistics.

	 show physical
	     Show low level link information.

	 show mp
	     Show Multi-link information.

	 show proto
	     Show current protocol totals.

	 show route
	     Show the current routing tables.

	 show stopped
	     Show the current stopped timeouts.

	 show timer
	     Show the active alarm timers.

	 show version
	     Show the current version number of	ppp.

     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	PPP peer is detected, ppp automatically	en-
	 ables Packet Mode and goes back into command mode.

MORE DETAILS
     +o	 Read the example configuration	files.	They are a good	source of in-
	 formation.

     +o	 Use "help", "nat ?", "enable ?", "set ?" and "show ?" to get online
	 information about what's available.

     +o	 The following URLs contain useful information:
	 +o   http://www.FreeBSD.org/doc/en_US.ISO8859-1/books/faq/ppp.html
	 +o   http://www.FreeBSD.org/doc/handbook/userppp.html

FILES
     ppp refers	to four	files: ppp.conf, ppp.linkup, ppp.linkdown and
     ppp.secret.  These	files are placed in the	/etc/ppp directory.

     /etc/ppp/ppp.conf
	 System	default	configuration file.

     /etc/ppp/ppp.secret
	 An authorisation file for each	system.

     /etc/ppp/ppp.linkup
	 A file	to check when ppp establishes a	network	level connection.

     /etc/ppp/ppp.linkdown
	 A file	to check when ppp closes a network level connection.

     /var/log/ppp.log
	 Logging and debugging information file.  Note,	this name is specified
	 in /etc/syslog.conf.  See syslog.conf(5) for further details.

     /var/spool/lock/LCK..*
	 tty port locking file.	 Refer to uucplock(3) for further details.

     /var/run/tunN.pid
	 The process id	(pid) of the ppp program connected to the tunN device,
	 where `N' is the number of the	device.

     /var/run/ttyXX.if
	 The tun interface used	by this	port.  Again, this file	is only	cre-
	 ated in -background, -auto and	-ddial modes.

     /etc/services
	 Get port number if port number	is using service name.

     /var/run/ppp-authname-class-value
	 In multi-link mode, local domain sockets are created using the	peer
	 authentication	name (`authname'), the peer endpoint discriminator
	 class (`class') and the peer endpoint discriminator value (`value').
	 As the	endpoint discriminator value may be a binary value, it is
	 turned	to HEX to determine the	actual file name.

	 This socket is	used to	pass links between different instances of ppp.

SEE ALSO
     at(1), ftp(1), gzip(1), hostname(1), login(1), tcpdump(1),	telnet(1),
     kldload(2), libalias(3), libradius(3), syslog(3), uucplock(3),
     netgraph(4), ng_pppoe(4), crontab(5), group(5), passwd(5),	protocols(5),
     radius.conf(5), resolv.conf(5), syslog.conf(5), adduser(8), chat(8),
     getty(8), inetd(8), init(8), isdnd(8), named(8), ping(8), pppctl(8),
     pppd(8), pppoed(8), route(8), sshd(8), syslogd(8),	traceroute(8), vipw(8)

HISTORY
     This program was originally written by Toshiharu OHNO <tony-o@iij.ad.jp>,
     and was submitted to FreeBSD 2.0.5	by Atsushi Murai <amurai@spec.co.jp>.

     It	was substantially modified during 1997 by Brian	Somers
     <brian@Awfulhak.org>, and was ported to OpenBSD in	November that year
     (just after the 2.2 release).

     Most of the code was rewritten by Brian Somers in early 1998 when multi-
     link ppp support was added.

BSD				 July 20, 2004				   BSD

NAME | SYNOPSIS | DESCRIPTION | Major Features | PERMISSIONS | GETTING STARTED | MANUAL DIALING | AUTOMATIC DIALING | BACKGROUND DIALING | DIAL ON DEMAND | RECEIVING INCOMING PPP CONNECTIONS (Method 1) | RECEIVING INCOMING PPP CONNECTIONS (Method 2) | AUTHENTICATING INCOMING CONNECTIONS | PPP OVER TCP and UDP (a.k.a Tunnelling) | NETWORK ADDRESS TRANSLATION (PACKET ALIASING) | PACKET FILTERING | SETTING THE IDLE TIMER | PREDICTOR-1 and DEFLATE COMPRESSION | CONTROLLING IP ADDRESS | CONNECTING WITH YOUR INTERNET SERVICE PROVIDER | LOGGING FACILITY | SIGNAL HANDLING | MULTI-LINK PPP | PPP COMMAND LIST | MORE DETAILS | FILES | SEE ALSO | HISTORY

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