Provided by: ppp_2.4.5~git20081126t100229-0ubuntu2_i386 bug

NAME

       pppd - Point-to-Point Protocol Daemon

SYNOPSIS

       pppd [ options ]

DESCRIPTION

       PPP  is  the protocol used for establishing internet links over dial-up
       modems, DSL connections, and many other types of point-to-point  links.
       The  pppd daemon works together with the kernel PPP driver to establish
       and maintain a PPP link with another system (called the  peer)  and  to
       negotiate  Internet  Protocol  (IP) addresses for each end of the link.
       Pppd can  also  authenticate  the  peer  and/or  supply  authentication
       information  to the peer.  PPP can be used with other network protocols
       besides IP, but such use is becoming increasingly rare.

FREQUENTLY USED OPTIONS

       ttyname
              Use the serial port called ttyname to communicate with the peer.
              If  ttyname  does not begin with a slash (/), the string "/dev/"
              is prepended to ttyname to form the name of the device to  open.
              If  no  device  name  is  given,  or if the name of the terminal
              connected to the standard input is given,  pppd  will  use  that
              terminal,  and will not fork to put itself in the background.  A
              value for  this  option  from  a  privileged  source  cannot  be
              overridden by a non-privileged user.

       speed  An  option that is a decimal number is taken as the desired baud
              rate for the serial device.   On  systems  such  as  4.4BSD  and
              NetBSD,  any speed can be specified.  Other systems (e.g. Linux,
              SunOS) only support the commonly-used baud rates.

       asyncmap map
              This option sets the Async-Control-Character-Map (ACCM) for this
              end  of the link.  The ACCM is a set of 32 bits, one for each of
              the ASCII control characters with values from 0 to 31, where a 1
              bit  indicates  that  the corresponding control character should
              not be used in PPP packets sent to  this  system.   The  map  is
              encoded as a hexadecimal number (without a leading 0x) where the
              least significant bit (00000001) represents character 0 and  the
              most  significant  bit (80000000) represents character 31.  Pppd
              will ask the peer to send these characters as  a  2-byte  escape
              sequence.   If  multiple  asyncmap options are given, the values
              are ORed together.  If no asyncmap option is given, the  default
              is  zero,  so  pppd  will ask the peer not to escape any control
              characters.  To escape transmitted characters,  use  the  escape
              option.

       auth   Require  the peer to authenticate itself before allowing network
              packets to be sent or received.  This option is the  default  if
              the  system has a default route.  If neither this option nor the
              noauth option is specified, pppd will only allow the peer to use
              IP  addresses to which the system does not already have a route.

       call name
              Read additional options from the file /etc/ppp/peers/name.  This
              file  may  contain  privileged  options, such as noauth, even if
              pppd is not being run by root.  The name string  may  not  begin
              with / or include .. as a pathname component.  The format of the
              options file is described below.

       connect script
              Usually there is something which needs to be done to prepare the
              link  before the PPP protocol can be started; for instance, with
              a dial-up modem, commands need to be sent to the modem  to  dial
              the  appropriate phone number.  This option specifies an command
              for pppd to execute (by passing it to a shell) before attempting
              to  start PPP negotiation.  The chat (8) program is often useful
              here, as it provides a way to send arbitrary strings to a  modem
              and  respond  to  received  characters.  A value for this option
              from  a  privileged  source  cannot  be  overridden  by  a  non-
              privileged user.

       crtscts
              Specifies  that  pppd should set the serial port to use hardware
              flow control using  the  RTS  and  CTS  signals  in  the  RS-232
              interface.   If  neither the crtscts, the nocrtscts, the cdtrcts
              nor the nocdtrcts option is given,  the  hardware  flow  control
              setting  for  the  serial  port  is left unchanged.  Some serial
              ports (such as Macintosh serial ports) lack a true  RTS  output.
              Such serial ports use this mode to implement unidirectional flow
              control.  The  serial  port  will  suspend   transmission   when
              requested  by  the modem (via CTS) but will be unable to request
              the modem to stop sending to the computer. This mode retains the
              ability to use DTR as a modem control line.

       defaultroute
              Add a default route to the system routing tables, using the peer
              as the gateway, when IPCP negotiation is successfully completed.
              This  entry  is removed when the PPP connection is broken.  This
              option is privileged  if  the  nodefaultroute  option  has  been
              specified.

       replacedefaultroute
              This   option   is   a  flag  to  the  defaultroute  option.  If
              defaultroute is set and this flag is also set, pppd replaces  an
              existing default route with the new default route.

       disconnect script
              Execute  the  command  specified  by  script, by passing it to a
              shell, after pppd has terminated the link.  This command  could,
              for  example, issue commands to the modem to cause it to hang up
              if hardware modem  control  signals  were  not  available.   The
              disconnect  script  is not run if the modem has already hung up.
              A value for this option  from  a  privileged  source  cannot  be
              overridden by a non-privileged user.

       escape xx,yy,...
              Specifies   that   certain   characters  should  be  escaped  on
              transmission (regardless of whether the peer requests them to be
              escaped  with  its async control character map).  The characters
              to be escaped are specified as a list of hex  numbers  separated
              by  commas.  Note that almost any character can be specified for
              the escape option, unlike the asyncmap option which only  allows
              control  characters  to  be specified.  The characters which may
              not be escaped are those with hex values 0x20 - 0x3f or 0x5e.

       file name
              Read options from file name (the  format  is  described  below).
              The file must be readable by the user who has invoked pppd.

       init script
              Execute  the  command  specified  by  script, by passing it to a
              shell,  to  initialize  the  serial  line.   This  script  would
              typically  use  the  chat(8)  program  to configure the modem to
              enable auto answer.  A value for this option from  a  privileged
              source cannot be overridden by a non-privileged user.

       lock   Specifies that pppd should create a UUCP-style lock file for the
              serial device to ensure exclusive  access  to  the  device.   By
              default, pppd will not create a lock file.

       mru n  Set the MRU [Maximum Receive Unit] value to n. Pppd will ask the
              peer to send packets of no more than n bytes.  The  value  of  n
              must  be between 128 and 16384; the default is 1500.  A value of
              296 works well on very slow links (40 bytes for TCP/IP header  +
              256  bytes  of  data).  Note that for the IPv6 protocol, the MRU
              must be at least 1280.

       mtu n  Set the MTU [Maximum Transmit Unit] value to n.  Unless the peer
              requests  a smaller value via MRU negotiation, pppd will request
              that the kernel networking code send data  packets  of  no  more
              than  n  bytes through the PPP network interface.  Note that for
              the IPv6 protocol, the MTU must be at least 1280.

       passive
              Enables the "passive" option in the LCP.  With this option, pppd
              will  attempt  to initiate a connection; if no reply is received
              from the peer, pppd will then just wait passively  for  a  valid
              LCP  packet  from  the  peer,  instead  of  exiting, as it would
              without this option.

OPTIONS

       <local_IP_address>:<remote_IP_address>
              Set the local and/or remote interface IP addresses.  Either  one
              may  be  omitted.  The IP addresses can be specified with a host
              name or in  decimal  dot  notation  (e.g.  150.234.56.78).   The
              default  local  address  is the (first) IP address of the system
              (unless the noipdefault option is given).   The  remote  address
              will  be  obtained from the peer if not specified in any option.
              Thus, in simple cases, this option is not required.  If a  local
              and/or  remote  IP  address  is specified with this option, pppd
              will not accept a different value from  the  peer  in  the  IPCP
              negotiation,     unless     the     ipcp-accept-local     and/or
              ipcp-accept-remote options are given, respectively.

       ipv6 <local_interface_identifier>,<remote_interface_identifier>
              Set the local and/or remote 64-bit interface identifier.  Either
              one may be omitted. The identifier must be specified in standard
              ascii notation of IPv6  addresses  (e.g.  ::dead:beef).  If  the
              ipv6cp-use-ipaddr  option  is given, the local identifier is the
              local IPv4 address (see above).  On  systems  which  supports  a
              unique  persistent  id, such as EUI-48 derived from the Ethernet
              MAC address, ipv6cp-use-persistent option can be used to replace
              the  ipv6  <local>,<remote>  option. Otherwise the identifier is
              randomized.

       active-filter filter-expression
              Specifies a packet filter to  be  applied  to  data  packets  to
              determine which packets are to be regarded as link activity, and
              therefore reset the idle timer, or cause the link to be  brought
              up   in   demand-dialling   mode.   This  option  is  useful  in
              conjunction with the idle option if there are packets being sent
              or  received  regularly  over  the  link  (for  example, routing
              information packets) which would otherwise prevent the link from
              ever  appearing  to be idle.  The filter-expression syntax is as
              described for  tcpdump(1),  except  that  qualifiers  which  are
              inappropriate  for  a  PPP  link, such as ether and arp, are not
              permitted.  Generally the filter expression should  be  enclosed
              in  single-quotes  to  prevent whitespace in the expression from
              being interpreted by the shell. This option  is  currently  only
              available   under  Linux,  and  requires  that  the  kernel  was
              configured to include PPP filtering support (CONFIG_PPP_FILTER).
              Note  that  it  is  possible  to  apply different constraints to
              incoming and outgoing packets using  the  inbound  and  outbound
              qualifiers.

       allow-ip address(es)
              Allow  peers  to  use  the  given  IP  address or subnet without
              authenticating themselves.  The parameter is parsed as for  each
              element of the list of allowed IP addresses in the secrets files
              (see the AUTHENTICATION section below).

       allow-number number
              Allow peers to connect  from  the  given  telephone  number.   A
              trailing ‘*’ character will match all numbers beginning with the
              leading part.

       bsdcomp nr,nt
              Request that the peer compress packets that it sends, using  the
              BSD-Compress  scheme,  with  a maximum code size of nr bits, and
              agree to compress packets sent to the peer with a  maximum  code
              size  of  nt  bits.   If nt is not specified, it defaults to the
              value given for nr.  Values in the range 9 to 15 may be used for
              nr  and  nt;  larger  values give better compression but consume
              more kernel memory for compression dictionaries.  Alternatively,
              a  value  of  0  for  nr  or  nt  disables  compression  in  the
              corresponding direction.  Use nobsdcomp or bsdcomp 0 to  disable
              BSD-Compress compression entirely.

       cdtrcts
              Use  a  non-standard  hardware  flow  control  (i.e. DTR/CTS) to
              control the flow of data on the serial  port.   If  neither  the
              crtscts,  the nocrtscts, the cdtrcts nor the nocdtrcts option is
              given, the hardware flow control setting for the serial port  is
              left  unchanged.   Some  serial  ports (such as Macintosh serial
              ports) lack a true RTS output. Such serial ports use  this  mode
              to  implement true bi-directional flow control. The sacrifice is
              that this flow control mode does not permit using DTR as a modem
              control line.

       chap-interval n
              If  this option is given, pppd will rechallenge the peer every n
              seconds.

       chap-max-challenge n
              Set the maximum number of  CHAP  challenge  transmissions  to  n
              (default 10).

       chap-restart n
              Set  the  CHAP  restart  interval  (retransmission  timeout  for
              challenges) to n seconds (default 3).

       child-timeout n
              When exiting, wait for up to n seconds for any  child  processes
              (such  as  the  command  specified with the pty command) to exit
              before exiting.  At the end of the timeout,  pppd  will  send  a
              SIGTERM  signal  to  any  remaining child processes and exit.  A
              value of 0 means no timeout, that is, pppd will wait  until  all
              child processes have exited.

       connect-delay n
              Wait  for up to n milliseconds after the connect script finishes
              for a valid PPP packet from the peer.  At the end of this  time,
              or  when a valid PPP packet is received from the peer, pppd will
              commence negotiation by  sending  its  first  LCP  packet.   The
              default value is 1000 (1 second).  This wait period only applies
              if the connect or pty option is used.

       debug  Enables connection debugging  facilities.   If  this  option  is
              given, pppd will log the contents of all control packets sent or
              received in a readable form.  The  packets  are  logged  through
              syslog  with  facility daemon and level debug.  This information
              can be  directed  to  a  file  by  setting  up  /etc/syslog.conf
              appropriately (see syslog.conf(5)).

       default-asyncmap
              Disable  asyncmap negotiation, forcing all control characters to
              be escaped for both the transmit and the receive direction.

       default-mru
              Disable MRU  [Maximum  Receive  Unit]  negotiation.   With  this
              option,  pppd  will  use the default MRU value of 1500 bytes for
              both the transmit and receive direction.

       deflate nr,nt
              Request that the peer compress packets that it sends, using  the
              Deflate  scheme,  with a maximum window size of 2**nr bytes, and
              agree to compress packets sent to the peer with a maximum window
              size of 2**nt bytes.  If nt is not specified, it defaults to the
              value given for nr.  Values in the range 9 to 15 may be used for
              nr  and  nt;  larger  values give better compression but consume
              more kernel memory for compression dictionaries.  Alternatively,
              a  value  of  0  for  nr  or  nt  disables  compression  in  the
              corresponding direction.  Use nodeflate or deflate 0 to  disable
              Deflate  compression  entirely.   (Note:  pppd  requests Deflate
              compression in preference to BSD-Compress if  the  peer  can  do
              either.)

       demand Initiate  the  link  only  on  demand, i.e. when data traffic is
              present.  With this  option,  the  remote  IP  address  must  be
              specified by the user on the command line or in an options file.
              Pppd will initially configure the interface and enable it for IP
              traffic  without  connecting  to  the  peer.   When  traffic  is
              available,  pppd  will  connect  to   the   peer   and   perform
              negotiation,  authentication, etc.  When this is completed, pppd
              will commence passing data packets (i.e., IP packets) across the
              link.

              The demand option implies the persist option.  If this behaviour
              is not desired,  use  the  nopersist  option  after  the  demand
              option.   The  idle  and  holdoff  options  are  also  useful in
              conjunction with the demand option.

       domain d
              Append  the  domain  name  d  to  the  local   host   name   for
              authentication  purposes.  For example, if gethostname() returns
              the name  porsche,  but  the  fully  qualified  domain  name  is
              porsche.Quotron.COM, you could specify domain Quotron.COM.  Pppd
              would then use  the  name  porsche.Quotron.COM  for  looking  up
              secrets  in the secrets file, and as the default name to send to
              the peer when authenticating itself to the peer.  This option is
              privileged.

       dryrun With  the  dryrun  option,  pppd  will  print out all the option
              values which have been set and  then  exit,  after  parsing  the
              command  line  and options files and checking the option values,
              but before initiating the link.  The option values are logged at
              level  info,  and  also  printed  to  standard output unless the
              device on standard output is the device that pppd would be using
              to communicate with the peer.

       dump   With  the dump option, pppd will print out all the option values
              which have been set.  This option  is  like  the  dryrun  option
              except that pppd proceeds as normal rather than exiting.

       enable-session
              Enables   session   accounting   via   PAM   or  wtwp/wtmpx,  as
              appropriate.   When  PAM  is  enabled,  the  PAM  "account"  and
              "session"  module stacks determine behavior, and are enabled for
              all  PPP  authentication  protocols.   When  PAM  is   disabled,
              wtmp/wtmpx  entries  are recorded regardless of whether the peer
              name identifies a valid user on the local system,  making  peers
              visible  in  the  last(1)  log.   This  feature is automatically
              enabled when the pppd login option is used.  Session  accounting
              is disabled by default.

       endpoint <epdisc>
              Sets the endpoint discriminator sent by the local machine to the
              peer during multilink negotiation to <epdisc>.  The  default  is
              to  use  the  MAC address of the first ethernet interface on the
              system, if any, otherwise the IPv4 address corresponding to  the
              hostname,  if  any,  provided  it  is  not  in  the multicast or
              locally-assigned IP address ranges, or  the  localhost  address.
              The endpoint discriminator can be the string null or of the form
              type:value, where type is a decimal number or one of the strings
              local,  IP, MAC, magic, or phone.  The value is an IP address in
              dotted-decimal notation for the IP type, or a string of bytes in
              hexadecimal, separated by periods or colons for the other types.
              For the MAC type, the value may also be the name of an  ethernet
              or  similar  network  interface.   This option is currently only
              available under Linux.

       eap-interval n
              If this option is given and pppd authenticates the peer with EAP
              (i.e.,  is  the  server),  pppd  will restart EAP authentication
              every n seconds.  For EAP SRP-SHA1, see  also  the  srp-interval
              option, which enables lightweight rechallenge.

       eap-max-rreq n
              Set  the  maximum  number  of  EAP  Requests  to which pppd will
              respond (as a client) without hearing EAP  Success  or  Failure.
              (Default is 20.)

       eap-max-sreq n
              Set  the maximum number of EAP Requests that pppd will issue (as
              a server) while attempting authentication.  (Default is 10.)

       eap-restart n
              Set the retransmit timeout for EAP Requests  when  acting  as  a
              server (authenticator).  (Default is 3 seconds.)

       eap-timeout n
              Set the maximum time to wait for the peer to send an EAP Request
              when  acting  as  a  client  (authenticatee).   (Default  is  20
              seconds.)

       hide-password
              When  logging  the  contents  of PAP packets, this option causes
              pppd to exclude the password string from the log.  This  is  the
              default.

       holdoff n
              Specifies how many seconds to wait before re-initiating the link
              after it terminates.  This option only has  any  effect  if  the
              persist  or  demand  option  is used.  The holdoff period is not
              applied if the link was terminated because it was idle.

       idle n Specifies that pppd should disconnect if the link is idle for  n
              seconds.   The  link  is  idle  when  no  data  packets (i.e. IP
              packets) are being sent or received.  Note: it is not  advisable
              to  use  this  option with the persist option without the demand
              option.  If the active-filter  option  is  given,  data  packets
              which  are  rejected by the specified activity filter also count
              as the link being idle.

       ipcp-accept-local
              With this option, pppd will accept the peer’s idea of our  local
              IP  address,  even  if  the local IP address was specified in an
              option.

       ipcp-accept-remote
              With this option, pppd  will  accept  the  peer’s  idea  of  its
              (remote) IP address, even if the remote IP address was specified
              in an option.

       ipcp-max-configure n
              Set the maximum number of IPCP  configure-request  transmissions
              to n (default 10).

       ipcp-max-failure n
              Set  the  maximum  number of IPCP configure-NAKs returned before
              starting to send configure-Rejects instead to n (default 10).

       ipcp-max-terminate n
              Set the maximum number of IPCP  terminate-request  transmissions
              to n (default 3).

       ipcp-restart n
              Set  the  IPCP  restart  interval  (retransmission timeout) to n
              seconds (default 3).

       ipparam string
              Provides an extra parameter to the ip-up, ip-pre-up and  ip-down
              scripts.   If this option is given, the string supplied is given
              as the 6th parameter to those scripts.

       ipv6cp-max-configure n
              Set the maximum number of IPv6CP configure-request transmissions
              to n (default 10).

       ipv6cp-max-failure n
              Set  the maximum number of IPv6CP configure-NAKs returned before
              starting to send configure-Rejects instead to n (default 10).

       ipv6cp-max-terminate n
              Set the maximum number of IPv6CP terminate-request transmissions
              to n (default 3).

       ipv6cp-restart n
              Set  the  IPv6CP  restart interval (retransmission timeout) to n
              seconds (default 3).

       ipx    Enable the IPXCP and IPX protocols.  This  option  is  presently
              only  supported  under  Linux,  and only if your kernel has been
              configured to include IPX support.

       ipx-network n
              Set the IPX network number in the IPXCP configure request  frame
              to  n, a hexadecimal number (without a leading 0x).  There is no
              valid default.  If this option is  not  specified,  the  network
              number is obtained from the peer.  If the peer does not have the
              network number, the IPX protocol will not be started.

       ipx-node n:m
              Set the IPX node numbers. The two  node  numbers  are  separated
              from  each  other  with a colon character. The first number n is
              the local node number. The second number m is  the  peer’s  node
              number.  Each  node  number  is a hexadecimal number, at most 10
              digits long. The node numbers on the ipx-network must be unique.
              There  is no valid default. If this option is not specified then
              the node numbers are obtained from the peer.

       ipx-router-name <string>
              Set the name of the router. This is a string and is sent to  the
              peer as information data.

       ipx-routing n
              Set  the  routing  protocol  to be received by this option. More
              than one instance of ipx-routing may be  specified.  The  ’none’
              option (0) may be specified as the only instance of ipx-routing.
              The values may be 0 for NONE, 2 for RIP/SAP, and 4 for NLSP.

       ipxcp-accept-local
              Accept the peer’s NAK for  the  node  number  specified  in  the
              ipx-node  option.  If a node number was specified, and non-zero,
              the default is to insist that the value be used. If you  include
              this  option then you will permit the peer to override the entry
              of the node number.

       ipxcp-accept-network
              Accept the peer’s NAK for the network number  specified  in  the
              ipx-network  option. If a network number was specified, and non-
              zero, the default is to insist that the value be  used.  If  you
              include  this  option  then you will permit the peer to override
              the entry of the node number.

       ipxcp-accept-remote
              Use the peer’s network number specified in the configure request
              frame.  If  a  node  number  was specified for the peer and this
              option was not specified, the peer will be  forced  to  use  the
              value which you have specified.

       ipxcp-max-configure n
              Set  the  maximum number of IPXCP configure request frames which
              the system will send to n. The default is 10.

       ipxcp-max-failure n
              Set the maximum number of  IPXCP  NAK  frames  which  the  local
              system  will  send  before  it  rejects the options. The default
              value is 3.

       ipxcp-max-terminate n
              Set the maximum nuber of IPXCP terminate request  frames  before
              the  local  system  considers  that the peer is not listening to
              them. The default value is 3.

       kdebug n
              Enable debugging code  in  the  kernel-level  PPP  driver.   The
              argument  values  depend  on  the specific kernel driver, but in
              general a value of 1 will enable general kernel debug  messages.
              (Note  that these messages are usually only useful for debugging
              the kernel driver itself.)  For the Linux 2.2.x  kernel  driver,
              the  value is a sum of bits: 1 to enable general debug messages,
              2 to request that the contents of received packets  be  printed,
              and  4  to  request  that the contents of transmitted packets be
              printed.  On most systems, messages printed by  the  kernel  are
              logged   by   syslog(1)   to   a   file   as   directed  in  the
              /etc/syslog.conf configuration file.

       ktune  Enables pppd to alter kernel  settings  as  appropriate.   Under
              Linux,    pppd    will    enable   IP   forwarding   (i.e.   set
              /proc/sys/net/ipv4/ip_forward to 1) if the  proxyarp  option  is
              used,  and  will  enable the dynamic IP address option (i.e. set
              /proc/sys/net/ipv4/ip_dynaddr to 1) in demand mode if the  local
              address changes.

       lcp-echo-failure n
              If  this  option is given, pppd will presume the peer to be dead
              if n LCP echo-requests are sent without receiving  a  valid  LCP
              echo-reply.    If   this   happens,   pppd  will  terminate  the
              connection.  Use of this option requires a  non-zero  value  for
              the  lcp-echo-interval  parameter.   This  option can be used to
              enable pppd to terminate after the physical connection has  been
              broken  (e.g.,  the  modem  has  hung up) in situations where no
              hardware modem control lines are available.

       lcp-echo-interval n
              If this option is given, pppd  will  send  an  LCP  echo-request
              frame  to  the  peer  every n seconds.  Normally the peer should
              respond to the echo-request  by  sending  an  echo-reply.   This
              option  can  be  used with the lcp-echo-failure option to detect
              that the peer is no longer connected.

       lcp-max-configure n
              Set the maximum number of LCP configure-request transmissions to
              n (default 10).

       lcp-max-failure n
              Set  the  maximum  number  of LCP configure-NAKs returned before
              starting to send configure-Rejects instead to n (default 10).

       lcp-max-terminate n
              Set the maximum number of LCP terminate-request transmissions to
              n (default 3).

       lcp-restart n
              Set  the  LCP  restart  interval  (retransmission  timeout) to n
              seconds (default 3).

       linkname name
              Sets the logical name of the link to name.  Pppd will  create  a
              file  named  ppp-name.pid  in  /var/run  (or  /etc/ppp  on  some
              systems) containing its process  ID.   This  can  be  useful  in
              determining  which  instance of pppd is responsible for the link
              to a given peer system.  This is a privileged option.

       local  Don’t use the modem control lines.  With this option, pppd  will
              ignore  the  state  of  the  CD (Carrier Detect) signal from the
              modem and will not change the state of the  DTR  (Data  Terminal
              Ready) signal.  This is the opposite of the modem option.

       logfd n
              Send  log  messages  to  file  descriptor n.  Pppd will send log
              messages to at most one file or  file  descriptor  (as  well  as
              sending  the  log  messages  to  syslog), so this option and the
              logfile option are mutually exclusive.  The default is for  pppd
              to  send  log messages to stdout (file descriptor 1), unless the
              serial port is already open on stdout.

       logfile filename
              Append log messages to the file filename (as well as sending the
              log messages to syslog).  The file is opened with the privileges
              of the user who invoked pppd, in append mode.

       login  Use the system password database  for  authenticating  the  peer
              using  PAP,  and  record the user in the system wtmp file.  Note
              that the peer must have an  entry  in  the  /etc/ppp/pap-secrets
              file  as  well  as  the  system  password database to be allowed
              access.  See also the enable-session option.

       maxconnect n
              Terminate the connection when it has been available for  network
              traffic  for  n  seconds (i.e. n seconds after the first network
              control protocol comes up).

       maxfail n
              Terminate after n consecutive  failed  connection  attempts.   A
              value of 0 means no limit.  The default value is 10.

       modem  Use  the modem control lines.  This option is the default.  With
              this option, pppd will wait for the CD (Carrier  Detect)  signal
              from  the  modem  to  be asserted when opening the serial device
              (unless a connect script is specified), and it will drop the DTR
              (Data  Terminal  Ready)  signal  briefly  when the connection is
              terminated and before executing the connect script.  On  Ultrix,
              this  option  implies  hardware flow control, as for the crtscts
              option.  This is the opposite of the local option.

       mp     Enables the use of PPP multilink;  this  is  an  alias  for  the
              ‘multilink’  option.   This  option  is currently only available
              under Linux.

       mppe-stateful
              Allow MPPE to  use  stateful  mode.   Stateless  mode  is  still
              attempted first.  The default is to disallow stateful mode.

       mpshortseq
              Enables  the use of short (12-bit) sequence numbers in multilink
              headers, as opposed to 24-bit sequence numbers.  This option  is
              only available under Linux, and only has any effect if multilink
              is enabled (see the multilink option).

       mrru n Sets the Maximum Reconstructed Receive Unit to n.  The  MRRU  is
              the  maximum  size  for a received packet on a multilink bundle,
              and is analogous to the MRU  for  the  individual  links.   This
              option is currently only available under Linux, and only has any
              effect if multilink is enabled (see the multilink option).

       ms-dns <addr>
              If pppd is acting as a server  for  Microsoft  Windows  clients,
              this  option  allows  pppd to supply one or two DNS (Domain Name
              Server) addresses to the clients.  The first  instance  of  this
              option  specifies  the  primary DNS address; the second instance
              (if given) specifies the secondary DNS  address.   (This  option
              was  present  in  some  older  versions  of  pppd under the name
              dns-addr.)

       ms-wins <addr>
              If pppd is acting as a server for Microsoft Windows  or  "Samba"
              clients,  this  option  allows  pppd  to  supply one or two WINS
              (Windows  Internet  Name  Services)  server  addresses  to   the
              clients.   The  first  instance  of  this  option  specifies the
              primary WINS address; the second instance (if  given)  specifies
              the secondary WINS address.

       multilink
              Enables the use of the PPP multilink protocol.  If the peer also
              supports multilink, then this link can become part of  a  bundle
              between  the local system and the peer.  If there is an existing
              bundle to the peer, pppd will join this  link  to  that  bundle,
              otherwise  pppd  will  create  a  new bundle.  See the MULTILINK
              section below.  This option is currently  only  available  under
              Linux.

       name name
              Set  the name of the local system for authentication purposes to
              name.  This is a privileged option.  With this option, pppd will
              use  lines  in  the  secrets files which have name as the second
              field when looking for a secret to  use  in  authenticating  the
              peer.  In addition, unless overridden with the user option, name
              will be used as the name to send to the peer when authenticating
              the  local  system to the peer.  (Note that pppd does not append
              the domain name to name.)

       noaccomp
              Disable Address/Control compression in both directions (send and
              receive).

       noauth Do  not require the peer to authenticate itself.  This option is
              privileged.

       nobsdcomp
              Disables BSD-Compress compression;  pppd  will  not  request  or
              agree to compress packets using the BSD-Compress scheme.

       noccp  Disable  CCP  (Compression  Control Protocol) negotiation.  This
              option should only be required if the peer  is  buggy  and  gets
              confused by requests from pppd for CCP negotiation.

       nocrtscts
              Disable hardware flow control (i.e. RTS/CTS) on the serial port.
              If neither the crtscts nor the nocrtscts nor the cdtrcts nor the
              nocdtrcts option is given, the hardware flow control setting for
              the serial port is left unchanged.

       nocdtrcts
              This option is a synonym for nocrtscts. Either of these  options
              will disable both forms of hardware flow control.

       nodefaultroute
              Disable  the  defaultroute option.  The system administrator who
              wishes to prevent users from adding a default  route  with  pppd
              can do so by placing this option in the /etc/ppp/options file.

       noreplacedefaultroute
              Disable the replacedefaultroute option. The system administrator
              who wishes to prevent users from replacing a default route  with
              pppd  can  do  so by placing this option in the /etc/ppp/options
              file.

       nodeflate
              Disables Deflate compression; pppd will not request or agree  to
              compress packets using the Deflate scheme.

       nodetach
              Don’t  detach  from  the  controlling  terminal.   Without  this
              option, if a serial  device  other  than  the  terminal  on  the
              standard  input  is  specified,  pppd  will  fork  to  become  a
              background process.

       noendpoint
              Disables pppd from sending an endpoint discriminator to the peer
              or  accepting  one  from  the  peer  (see  the MULTILINK section
              below).  This option should only be  required  if  the  peer  is
              buggy.

       noip   Disable  IPCP  negotiation  and  IP  communication.  This option
              should only be required if the peer is buggy and  gets  confused
              by requests from pppd for IPCP negotiation.

       noipv6 Disable  IPv6CP  negotiation and IPv6 communication. This option
              should only be required if the peer is buggy and  gets  confused
              by requests from pppd for IPv6CP negotiation.

       noipdefault
              Disables  the  default  behaviour  when  no  local IP address is
              specified, which is to determine  (if  possible)  the  local  IP
              address from the hostname.  With this option, the peer will have
              to supply the local IP address during IPCP  negotiation  (unless
              it  specified  explicitly  on  the command line or in an options
              file).

       noipx  Disable the IPXCP and IPX protocols.  This option should only be
              required if the peer is buggy and gets confused by requests from
              pppd for IPXCP negotiation.

       noktune
              Opposite of the ktune option; disables pppd from changing system
              settings.

       nolock Opposite  of  the  lock  option;  specifies that pppd should not
              create a UUCP-style lock  file  for  the  serial  device.   This
              option is privileged.

       nolog  Do  not  send  log  messages to a file or file descriptor.  This
              option cancels the logfd and logfile options.

       nomagic
              Disable magic number negotiation.  With this option, pppd cannot
              detect a looped-back line.  This option should only be needed if
              the peer is buggy.

       nomp   Disables the use of PPP multilink.   This  option  is  currently
              only available under Linux.

       nomppe Disables  MPPE  (Microsoft  Point to Point Encryption).  This is
              the default.

       nomppe-40
              Disable 40-bit encryption with MPPE.

       nomppe-128
              Disable 128-bit encryption with MPPE.

       nomppe-stateful
              Disable MPPE stateful mode.  This is the default.

       nompshortseq
              Disables the use of short (12-bit) sequence numbers in  the  PPP
              multilink  protocol, forcing the use of 24-bit sequence numbers.
              This option is currently only available under  Linux,  and  only
              has any effect if multilink is enabled.

       nomultilink
              Disables  the  use  of  PPP multilink.  This option is currently
              only available under Linux.

       nopcomp
              Disable protocol  field  compression  negotiation  in  both  the
              receive and the transmit direction.

       nopersist
              Exit  once  a  connection has been made and terminated.  This is
              the default  unless  the  persist  or  demand  option  has  been
              specified.

       nopredictor1
              Do not accept or agree to Predictor-1 compression.

       noproxyarp
              Disable  the  proxyarp  option.   The  system  administrator who
              wishes to prevent users from creating  proxy  ARP  entries  with
              pppd  can  do  so by placing this option in the /etc/ppp/options
              file.

       noremoteip
              Allow pppd to operate without having an IP address for the peer.
              This  option is only available under Linux.  Normally, pppd will
              request the peer’s IP address, and if the peer does  not  supply
              it,  pppd  will not bring up the link for IP traffic.  With this
              option, if the peer does not supply its IP  address,  pppd  will
              not  ask  the  peer  for  it,  and  will not set the destination
              address of the  ppp  interface.   In  this  situation,  the  ppp
              interface can be used for routing by creating device routes, but
              the peer itself cannot be addressed directly for IP traffic.

       notty  Normally, pppd requires a terminal device.   With  this  option,
              pppd will allocate itself a pseudo-tty master/slave pair and use
              the slave as its terminal device.   Pppd  will  create  a  child
              process  to  act  as  a ‘character shunt’ to transfer characters
              between the pseudo-tty master and its standard input and output.
              Thus  pppd  will  transmit characters on its standard output and
              receive characters on its standard input even if  they  are  not
              terminal  devices.   This  option  increases the latency and CPU
              overhead of transferring data over the ppp interface as  all  of
              the characters sent and received must flow through the character
              shunt process.  An explicit device name may not be given if this
              option is used.

       novj   Disable Van Jacobson style TCP/IP header compression in both the
              transmit and the receive direction.

       novjccomp
              Disable the connection-ID compression  option  in  Van  Jacobson
              style  TCP/IP  header  compression.  With this option, pppd will
              not omit the connection-ID byte  from  Van  Jacobson  compressed
              TCP/IP headers, nor ask the peer to do so.

       papcrypt
              Indicates  that  all  secrets  in  the /etc/ppp/pap-secrets file
              which are used  for  checking  the  identity  of  the  peer  are
              encrypted,  and  thus  pppd  should not accept a password which,
              before  encryption,  is  identical  to  the  secret   from   the
              /etc/ppp/pap-secrets file.

       pap-max-authreq n
              Set the maximum number of PAP authenticate-request transmissions
              to n (default 10).

       pap-restart n
              Set the PAP  restart  interval  (retransmission  timeout)  to  n
              seconds (default 3).

       pap-timeout n
              Set  the  maximum  time  that  pppd  will  wait  for the peer to
              authenticate itself with PAP to n seconds (0 means no limit).

       pass-filter filter-expression
              Specifies a packet filter to applied to data packets being  sent
              or  received  to  determine  which  packets should be allowed to
              pass.  Packets which are rejected by  the  filter  are  silently
              discarded.   This option can be used to prevent specific network
              daemons (such as routed) using up link bandwidth, or to  provide
              a  very basic firewall capability.  The filter-expression syntax
              is as described for tcpdump(1), except that qualifiers which are
              inappropriate  for  a  PPP  link, such as ether and arp, are not
              permitted.  Generally the filter expression should  be  enclosed
              in  single-quotes  to  prevent whitespace in the expression from
              being interpreted by the shell.  Note that  it  is  possible  to
              apply  different  constraints  to  incoming and outgoing packets
              using the  inbound  and  outbound  qualifiers.  This  option  is
              currently  only  available  under  Linux,  and requires that the
              kernel  was  configured  to  include   PPP   filtering   support
              (CONFIG_PPP_FILTER).

       password password-string
              Specifies  the  password  to use for authenticating to the peer.
              Use of this option is discouraged, as the password is likely  to
              be  visible  to other users on the system (for example, by using
              ps(1)).

       persist
              Do not exit after a connection is  terminated;  instead  try  to
              reopen the connection. The maxfail option still has an effect on
              persistent connections.

       plugin filename
              Load the shared library object file filename as a plugin.   This
              is  a  privileged  option.  If filename does not contain a slash
              (/), pppd will look in the /usr/lib/pppd/version  directory  for
              the  plugin,  where  version  is the version number of pppd (for
              example, 2.4.2).

       predictor1
              Request that the  peer  compress  frames  that  it  sends  using
              Predictor-1  compression,  and  agree  to  compress  transmitted
              frames with Predictor-1 if requested.  This option has no effect
              unless the kernel driver supports Predictor-1 compression.

       privgroup group-name
              Allows  members  of  group group-name to use privileged options.
              This is a privileged option.  Use of this option  requires  care
              as  there  is no guarantee that members of group-name cannot use
              pppd to become  root  themselves.   Consider  it  equivalent  to
              putting the members of group-name in the kmem or disk group.

       proxyarp
              Add  an entry to this system’s ARP [Address Resolution Protocol]
              table with the IP address of the peer and the  Ethernet  address
              of  this  system.   This will have the effect of making the peer
              appear to other systems to be on the local ethernet.

       pty script
              Specifies that the command script is to be used  to  communicate
              rather  than  a  specific  terminal  device.  Pppd will allocate
              itself a pseudo-tty master/slave pair and use the slave  as  its
              terminal device.  The script will be run in a child process with
              the pseudo-tty master as its  standard  input  and  output.   An
              explicit  device  name  may not be given if this option is used.
              (Note: if the record option is used in conjunction with the  pty
              option,  the child process will have pipes on its standard input
              and output.)

       receive-all
              With this option, pppd will accept all control  characters  from
              the  peer,  including  those  marked  in  the  receive asyncmap.
              Without this option,  pppd  will  discard  those  characters  as
              specified  in RFC1662.  This option should only be needed if the
              peer is buggy.

       record filename
              Specifies that  pppd  should  record  all  characters  sent  and
              received  to  a  file  named  filename.   This file is opened in
              append mode, using the user’s  user-ID  and  permissions.   This
              option  is  implemented  using  a  pseudo-tty  and  a process to
              transfer characters between the pseudo-tty and the  real  serial
              device,  so  it  will  increase  the latency and CPU overhead of
              transferring data over the ppp interface.   The  characters  are
              stored  in  a  tagged  format  with  timestamps,  which  can  be
              displayed in readable form using the pppdump(8) program.

       remotename name
              Set the assumed name of the  remote  system  for  authentication
              purposes to name.

       remotenumber number
              Set  the  assumed  telephone  number  of  the  remote system for
              authentication purposes to number.

       refuse-chap
              With this option, pppd will not agree to authenticate itself  to
              the peer using CHAP.

       refuse-mschap
              With  this option, pppd will not agree to authenticate itself to
              the peer using MS-CHAP.

       refuse-mschap-v2
              With this option, pppd will not agree to authenticate itself  to
              the peer using MS-CHAPv2.

       refuse-eap
              With  this option, pppd will not agree to authenticate itself to
              the peer using EAP.

       refuse-pap
              With this option, pppd will not agree to authenticate itself  to
              the peer using PAP.

       require-chap
              Require  the  peer  to authenticate itself using CHAP [Challenge
              Handshake Authentication Protocol] authentication.

       require-mppe
              Require the use of MPPE (Microsoft Point to  Point  Encryption).
              This  option  disables all other compression types.  This option
              enables both 40-bit and 128-bit encryption.  In order  for  MPPE
              to successfully come up, you must have authenticated with either
              MS-CHAP or MS-CHAPv2.  This option is presently  only  supported
              under  Linux,  and  only  if  your kernel has been configured to
              include MPPE support.

       require-mppe-40
              Require the use of MPPE, with 40-bit encryption.

       require-mppe-128
              Require the use of MPPE, with 128-bit encryption.

       require-mschap
              Require the peer to authenticate itself using MS-CHAP [Microsoft
              Challenge Handshake Authentication Protocol] authentication.

       require-mschap-v2
              Require   the   peer  to  authenticate  itself  using  MS-CHAPv2
              [Microsoft Challenge Handshake Authentication Protocol,  Version
              2] authentication.

       require-eap
              Require  the  peer  to authenticate itself using EAP [Extensible
              Authentication Protocol] authentication.

       require-pap
              Require the peer to  authenticate  itself  using  PAP  [Password
              Authentication Protocol] authentication.

       show-password
              When  logging  the  contents  of PAP packets, this option causes
              pppd to show the password string in the log message.

       silent With this option, pppd will not transmit LCP packets to initiate
              a  connection until a valid LCP packet is received from the peer
              (as for the ‘passive’ option with ancient versions of pppd).

       srp-interval n
              If this parameter  is  given  and  pppd  uses  EAP  SRP-SHA1  to
              authenticate  the peer (i.e., is the server), then pppd will use
              the optional lightweight SRP rechallenge mechanism at  intervals
              of   n   seconds.   This  option  is  faster  than  eap-interval
              reauthentication because it uses a hash-based mechanism and does
              not derive a new session key.

       srp-pn-secret string
              Set  the  long-term  pseudonym-generating secret for the server.
              This value is optional and if set, needs  to  be  known  at  the
              server  (authenticator)  side  only, and should be different for
              each server (or poll of identical servers).  It  is  used  along
              with  the  current date to generate a key to encrypt and decrypt
              the client’s identity contained in the pseudonym.

       srp-use-pseudonym
              When operating as an EAP SRP-SHA1 client,  attempt  to  use  the
              pseudonym  stored in ~/.ppp_pseudonym first as the identity, and
              save in this file any  pseudonym  offered  by  the  peer  during
              authentication.

       sync   Use  synchronous  HDLC  serial encoding instead of asynchronous.
              The device used by pppd with this option must have sync support.
              Currently  supports  Microgate SyncLink adapters under Linux and
              FreeBSD 2.2.8 and later.

       unit num
              Sets the ppp unit number (for a ppp0 or ppp1 etc interface name)
              for outbound connections.

       updetach
              With this option, pppd will detach from its controlling terminal
              once it has successfully established the ppp connection (to  the
              point  where  the first network control protocol, usually the IP
              control protocol, has come up).

       usehostname
              Enforce the use of the hostname (with domain name  appended,  if
              given)  as  the  name  of  the  local  system for authentication
              purposes (overrides  the  name  option).   This  option  is  not
              normally needed since the name option is privileged.

       usepeerdns
              Ask  the  peer  for up to 2 DNS server addresses.  The addresses
              supplied by the peer (if any) are passed to  the  /etc/ppp/ip-up
              script  in  the  environment  variables  DNS1  and DNS2, and the
              environment variable USEPEERDNS will be set to 1.  In  addition,
              pppd  will create an /etc/ppp/resolv.conf file containing one or
              two nameserver lines with the address(es) supplied by the  peer.

       user name
              Sets  the  name  used for authenticating the local system to the
              peer to name.

       vj-max-slots n
              Sets the number of connection  slots  to  be  used  by  the  Van
              Jacobson  TCP/IP header compression and decompression code to n,
              which must be between 2 and 16 (inclusive).

       welcome script
              Run the executable or shell command specified by  script  before
              initiating  PPP  negotiation,  after the connect script (if any)
              has completed.  A value for this option from a privileged source
              cannot be overridden by a non-privileged user.

       xonxoff
              Use software flow control (i.e. XON/XOFF) to control the flow of
              data on the serial port.

OPTIONS FILES

       Options can be taken from files as well  as  the  command  line.   Pppd
       reads   options   from   the   files   /etc/ppp/options,  ~/.ppprc  and
       /etc/ppp/options.ttyname (in that order) before processing the  options
       on the command line.  (In fact, the command-line options are scanned to
       find the terminal name before the options.ttyname file  is  read.)   In
       forming  the  name  of  the  options.ttyname file, the initial /dev/ is
       removed from the terminal name, and  any  remaining  /  characters  are
       replaced with dots.

       An  options  file  is  parsed  into  a  series  of  words, delimited by
       whitespace.  Whitespace can be included in a word by enclosing the word
       in  double-quotes (").  A backslash (\) quotes the following character.
       A hash (#) starts a comment, which continues until the end of the line.
       There  is  no  restriction  on using the file or call options within an
       options file.

SECURITY

       pppd provides system administrators with sufficient access control that
       PPP  access  to  a  server  machine can be provided to legitimate users
       without fear of compromising the security of the server or the  network
       it’s  on.   This  control  is provided through restrictions on which IP
       addresses the peer may use, based on  its  authenticated  identity  (if
       any),  and  through restrictions on which options a non-privileged user
       may use.  Several of pppd’s options are privileged, in particular those
       which  permit  potentially  insecure  configurations; these options are
       only accepted in files which  are  under  the  control  of  the  system
       administrator, or if pppd is being run by root.

       The  default  behaviour  of pppd is to allow an unauthenticated peer to
       use a given IP address only if the system does not already have a route
       to  that IP address.  For example, a system with a permanent connection
       to the wider internet will normally have a default route, and thus  all
       peers  will  have  to  authenticate  themselves  in  order  to set up a
       connection.  On such a system, the auth option is the default.  On  the
       other  hand,  a system where the PPP link is the only connection to the
       internet will not normally have a default route, so the  peer  will  be
       able to use almost any IP address without authenticating itself.

       As  indicated  above,  some  security-sensitive options are privileged,
       which means that they may not be used  by  an  ordinary  non-privileged
       user  running  a  setuid-root  pppd, either on the command line, in the
       user’s ~/.ppprc file, or in an options file read using the file option.
       Privileged  options  may  be  used  in  /etc/ppp/options  file or in an
       options file read using the call option.  If pppd is being run  by  the
       root user, privileged options can be used without restriction.

       When  opening  the device, pppd uses either the invoking user’s user ID
       or the root UID (that is, 0), depending on whether the device name  was
       specified  by the user or the system administrator.  If the device name
       comes from a privileged source, that is, /etc/ppp/options or an options
       file  read  using  the call option, pppd uses full root privileges when
       opening the device.   Thus,  by  creating  an  appropriate  file  under
       /etc/ppp/peers, the system administrator can allow users to establish a
       ppp connection  via  a  device  which  they  would  not  normally  have
       permission to access.  Otherwise pppd uses the invoking user’s real UID
       when opening the device.

AUTHENTICATION

       Authentication is the process whereby one peer convinces the  other  of
       its  identity.   This  involves  the first peer sending its name to the
       other, together with some kind of secret information which  could  only
       come  from  the  genuine  authorized  user  of  that  name.  In such an
       exchange, we will call the first peer the "client" and  the  other  the
       "server".   The  client has a name by which it identifies itself to the
       server, and the server also has a name by which it identifies itself to
       the  client.   Generally  the  genuine  client  shares  some secret (or
       password) with the server, and authenticates itself by proving that  it
       knows  that  secret.   Very  often,  the  names used for authentication
       correspond to the internet hostnames of the  peers,  but  this  is  not
       essential.

       At  present, pppd supports three authentication protocols: the Password
       Authentication  Protocol  (PAP),  Challenge  Handshake   Authentication
       Protocol  (CHAP),  and  Extensible  Authentication Protocol (EAP).  PAP
       involves the client sending its name and a cleartext  password  to  the
       server  to  authenticate itself.  In contrast, the server initiates the
       CHAP authentication exchange by sending a challenge to the client  (the
       challenge  packet includes the server’s name).  The client must respond
       with a response which includes its name plus a hash value derived  from
       the  shared  secret  and the challenge, in order to prove that it knows
       the secret.  EAP supports CHAP-style authentication, and also  includes
       the  SRP-SHA1 mechanism, which is resistant to dictionary-based attacks
       and does not require a cleartext password on the server side.

       The PPP protocol, being symmetrical, allows both peers to  require  the
       other   to  authenticate  itself.   In  that  case,  two  separate  and
       independent authentication exchanges will  occur.   The  two  exchanges
       could   use  different  authentication  protocols,  and  in  principle,
       different names could be used in the two exchanges.

       The default behaviour of pppd is to agree to authenticate if requested,
       and  to  not  require authentication from the peer.  However, pppd will
       not agree to authenticate itself with a particular protocol if  it  has
       no secrets which could be used to do so.

       Pppd  stores  secrets  for  use  in  authentication  in  secrets  files
       (/etc/ppp/pap-secrets for PAP, /etc/ppp/chap-secrets for CHAP, MS-CHAP,
       MS-CHAPv2,  and  EAP  MD5-Challenge,  and  /etc/ppp/srp-secrets for EAP
       SRP-SHA1).  All secrets files have the same format.  The secrets  files
       can  contain  secrets for pppd to use in authenticating itself to other
       systems, as well as secrets for pppd to use when  authenticating  other
       systems to itself.

       Each  line  in  a  secrets file contains one secret.  A given secret is
       specific to a particular combination of client and server - it can only
       be  used  by  that  client to authenticate itself to that server.  Thus
       each line in a secrets file has at least 3  fields:  the  name  of  the
       client,  the  name  of the server, and the secret.  These fields may be
       followed by a list of the IP addresses that the  specified  client  may
       use when connecting to the specified server.

       A  secrets  file  is  parsed  into  words as for a options file, so the
       client name, server name and secrets fields must each be one word, with
       any  embedded  spaces  or  other  special characters quoted or escaped.
       Note that case is significant in the client and server names and in the
       secret.

       If  the  secret  starts  with an ‘@’, what follows is assumed to be the
       name of a file from which to read the secret.  A "*" as the  client  or
       server  name matches any name.  When selecting a secret, pppd takes the
       best match, i.e.  the match with the fewest wildcards.

       Any following words on the  same  line  are  taken  to  be  a  list  of
       acceptable  IP addresses for that client.  If there are only 3 words on
       the line, or if the first word  is  "-",  then  all  IP  addresses  are
       disallowed.   To  allow any address, use "*".  A word starting with "!"
       indicates that the specified address is not acceptable.  An address may
       be followed by "/" and a number n, to indicate a whole subnet, i.e. all
       addresses which have the same value in the most significant n bits.  In
       this form, the address may be followed by a plus sign ("+") to indicate
       that one address from the  subnet  is  authorized,  based  on  the  ppp
       network  interface  unit number in use.  In this case, the host part of
       the address will be set to the unit number plus one.

       Thus a secrets file contains both secrets  for  use  in  authenticating
       other  hosts, plus secrets which we use for authenticating ourselves to
       others.  When pppd is authenticating  the  peer  (checking  the  peer’s
       identity),  it chooses a secret with the peer’s name in the first field
       and the name of the local system in the second field.  The name of  the
       local system defaults to the hostname, with the domain name appended if
       the domain option is used.  This default can  be  overridden  with  the
       name  option,  except  when  the  usehostname option is used.  (For EAP
       SRP-SHA1, see the srp-entry(8) utility for generating proper  validator
       entries to be used in the "secret" field.)

       When  pppd  is choosing a secret to use in authenticating itself to the
       peer, it first determines what name it is  going  to  use  to  identify
       itself  to  the  peer.  This name can be specified by the user with the
       user option.  If this option is not used, the name defaults to the name
       of the local system, determined as described in the previous paragraph.
       Then pppd looks for a secret with this name in the first field and  the
       peer’s  name  in the second field.  Pppd will know the name of the peer
       if CHAP or EAP authentication is being used, because the peer will have
       sent  it  in the challenge packet.  However, if PAP is being used, pppd
       will have to determine the peer’s name from the  options  specified  by
       the  user.   The  user  can  specify  the peer’s name directly with the
       remotename option.  Otherwise, if the remote IP address  was  specified
       by  a name (rather than in numeric form), that name will be used as the
       peer’s name.  Failing that, pppd will use the null string as the peer’s
       name.

       When  authenticating  the peer with PAP, the supplied password is first
       compared with the secret  from  the  secrets  file.   If  the  password
       doesn’t  match  the secret, the password is encrypted using crypt() and
       checked against the secret again.  Thus secrets for authenticating  the
       peer  can  be  stored  in  encrypted  form if desired.  If the papcrypt
       option is given, the first (unencrypted)  comparison  is  omitted,  for
       better security.

       Furthermore,  if  the  login  option  was  specified,  the username and
       password are also checked against the system password database.   Thus,
       the  system  administrator can set up the pap-secrets file to allow PPP
       access only to certain users, and to restrict the set of  IP  addresses
       that  each  user  can use.  Typically, when using the login option, the
       secret in /etc/ppp/pap-secrets  would  be  "",  which  will  match  any
       password  supplied  by the peer.  This avoids the need to have the same
       secret in two places.

       Authentication must be satisfactorily completed  before  IPCP  (or  any
       other  Network  Control  Protocol)  can  be  started.   If  the peer is
       required to  authenticate  itself,  and  fails  to  do  so,  pppd  will
       terminated   the   link  (by  closing  LCP).   If  IPCP  negotiates  an
       unacceptable IP address for the remote host, IPCP will be  closed.   IP
       packets can only be sent or received when IPCP is open.

       In  some  cases  it  is  desirable  to  allow  some  hosts  which can’t
       authenticate themselves to connect and use one of a restricted  set  of
       IP   addresses,   even   when   the   local   host  generally  requires
       authentication.  If  the  peer  refuses  to  authenticate  itself  when
       requested,  pppd  takes  that  as equivalent to authenticating with PAP
       using the empty string for the username and password.  Thus, by  adding
       a line to the pap-secrets file which specifies the empty string for the
       client and password, it is possible to allow restricted access to hosts
       which refuse to authenticate themselves.

ROUTING

       When  IPCP  negotiation is completed successfully, pppd will inform the
       kernel of the local and remote IP  addresses  for  the  ppp  interface.
       This  is  sufficient  to  create  a host route to the remote end of the
       link,  which  will  enable  the   peers   to   exchange   IP   packets.
       Communication   with   other   machines   generally   requires  further
       modification to routing tables and/or ARP (Address Resolution Protocol)
       tables.   In  most  cases  the defaultroute and/or proxyarp options are
       sufficient  for  this,  but  in  some  cases  further  intervention  is
       required.  The /etc/ppp/ip-up script can be used for this.

       Sometimes  it  is  desirable  to add a default route through the remote
       host, as in the case of a machine whose only connection to the Internet
       is  through  the ppp interface.  The defaultroute option causes pppd to
       create such a default route when IPCP comes up, and delete it when  the
       link is terminated.

       In some cases it is desirable to use proxy ARP, for example on a server
       machine  connected  to  a  LAN,  in  order  to  allow  other  hosts  to
       communicate  with  the remote host.  The proxyarp option causes pppd to
       look for a network interface on the same subnet as the remote host  (an
       interface supporting broadcast and ARP, which is up and not a point-to-
       point or loopback interface).  If  found,  pppd  creates  a  permanent,
       published  ARP  entry  with  the  IP address of the remote host and the
       hardware address of the network interface found.

       When the demand option is used, the interface IP addresses have already
       been set at the point when IPCP comes up.  If pppd has not been able to
       negotiate the same addresses that it used to  configure  the  interface
       (for  example  when  the  peer  is  an ISP that uses dynamic IP address
       assignment), pppd has to change  the  interface  IP  addresses  to  the
       negotiated  addresses.   This may disrupt existing connections, and the
       use of demand dialling with peers that do dynamic IP address assignment
       is not recommended.

MULTILINK

       Multilink  PPP provides the capability to combine two or more PPP links
       between a pair of machines into a single ‘bundle’, which appears  as  a
       single  virtual  PPP  link  which  has  the  combined  bandwidth of the
       individual links.  Currently, multilink PPP  is  only  supported  under
       Linux.

       Pppd  detects  that the link it is controlling is connected to the same
       peer as another link using the peer’s endpoint  discriminator  and  the
       authenticated  identity  of the peer (if it authenticates itself).  The
       endpoint discriminator is a block of data which is hopefully unique for
       each  peer.   Several  types  of  data  can be used, including locally-
       assigned strings  of  bytes,  IP  addresses,  MAC  addresses,  randomly
       strings  of  bytes, or E-164 phone numbers.  The endpoint discriminator
       sent to the peer by pppd can be set using the endpoint option.

       In some circumstances the peer may send no endpoint discriminator or  a
       non-unique  value.   The  bundle  option  adds an extra string which is
       added to the peer’s endpoint discriminator and  authenticated  identity
       when  matching  up links to be joined together in a bundle.  The bundle
       option can also be used to allow the establishment of multiple  bundles
       between  the  local  system  and the peer.  Pppd uses a TDB database in
       /var/run/pppd2.tdb to match up links.

       Assuming that multilink is enabled and the peer is willing to negotiate
       multilink,  then when pppd is invoked to bring up the first link to the
       peer, it will detect that no other link is connected to  the  peer  and
       create a new bundle, that is, another ppp network interface unit.  When
       another pppd is invoked to bring up another link to the peer,  it  will
       detect the existing bundle and join its link to it.

       If  the  first  link  terminates (for example, because of a hangup or a
       received LCP terminate-request) the  bundle  is  not  destroyed  unless
       there are no other links remaining in the bundle.  Rather than exiting,
       the first pppd keeps running after its link terminates, until  all  the
       links  in  the  bundle  have  terminated.  If the first pppd receives a
       SIGTERM or SIGINT signal, it will destroy the bundle and send a  SIGHUP
       to  the  pppd  processes  for  each of the links in the bundle.  If the
       first pppd receives a SIGHUP signal, it will terminate its link but not
       the bundle.

       Note: demand mode is not currently supported with multilink.

EXAMPLES

       The  following  examples assume that the /etc/ppp/options file contains
       the auth option (as in the default /etc/ppp/options  file  in  the  ppp
       distribution).

       Probably  the  most  common use of pppd is to dial out to an ISP.  This
       can be done with a command such as

              pppd call isp

       where the /etc/ppp/peers/isp file is set up by the system administrator
       to contain something like this:

              ttyS0 19200 crtscts
              connect ’/usr/sbin/chat -v -f /etc/ppp/chat-isp’
              noauth

       In  this  example,  we  are  using  chat to dial the ISP’s modem and go
       through  any  logon  sequence  required.   The  /etc/ppp/chat-isp  file
       contains  the  script  used  by  chat;  it  could  for  example contain
       something like this:

              ABORT "NO CARRIER"
              ABORT "NO DIALTONE"
              ABORT "ERROR"
              ABORT "NO ANSWER"
              ABORT "BUSY"
              ABORT "Username/Password Incorrect"
              "" "at"
              OK "at&d0&c1"
              OK "atdt2468135"
              "name:" "^Umyuserid"
              "word:" "\qmypassword"
              "ispts" "\q^Uppp"
              "~-^Uppp-~"

       See the chat(8) man page for details of chat scripts.

       Pppd can also be used to provide a dial-in ppp service for  users.   If
       the  users  already have login accounts, the simplest way to set up the
       ppp service is to let the users log in to their accounts and  run  pppd
       (installed setuid-root) with a command such as

              pppd proxyarp

       To  allow  a user to use the PPP facilities, you need to allocate an IP
       address  for   that   user’s   machine   and   create   an   entry   in
       /etc/ppp/pap-secrets,  /etc/ppp/chap-secrets,  or  /etc/ppp/srp-secrets
       (depending on which authentication method the PPP implementation on the
       user’s  machine  supports), so that the user’s machine can authenticate
       itself.  For example, if Joe has a machine called "joespc" that  is  to
       be  allowed  to  dial  in to the machine called "server" and use the IP
       address  joespc.my.net,  you  would  add  an   entry   like   this   to
       /etc/ppp/pap-secrets or /etc/ppp/chap-secrets:

              joespc    server    "joe’s secret" joespc.my.net

       (See  srp-entry(8)  for  a  means  to  generate the server’s entry when
       SRP-SHA1 is in use.)  Alternatively, you can create a  username  called
       (for example) "ppp", whose login shell is pppd and whose home directory
       is /etc/ppp.  Options to be used when pppd is run this way can  be  put
       in /etc/ppp/.ppprc.

       If your serial connection is any more complicated than a piece of wire,
       you may need to arrange for some control characters to be escaped.   In
       particular,  it is often useful to escape XON (^Q) and XOFF (^S), using
       asyncmap a0000.  If the path includes a  telnet,  you  probably  should
       escape ^] as well (asyncmap 200a0000).  If the path includes an rlogin,
       you will need to use the escape ff option on the end which  is  running
       the   rlogin   client,   since  many  rlogin  implementations  are  not
       transparent; they will remove the sequence  [0xff,  0xff,  0x73,  0x73,
       followed by any 8 bytes] from the stream.

DIAGNOSTICS

       Messages  are  sent  to  the  syslog  daemon using facility LOG_DAEMON.
       (This can be overridden by recompiling  pppd  with  the  macro  LOG_PPP
       defined  as the desired facility.)  See the syslog(8) documentation for
       details of where the syslog daemon will write the  messages.   On  most
       systems,  the  syslog  daemon uses the /etc/syslog.conf file to specify
       the destination(s) for syslog messages.  You may need to edit that file
       to suit.

       The  debug  option  causes  the contents of all control packets sent or
       received to be logged, that is,  all  LCP,  PAP,  CHAP,  EAP,  or  IPCP
       packets.  This can be useful if the PPP negotiation does not succeed or
       if authentication fails.  If debugging is enabled at compile time,  the
       debug option also causes other debugging messages to be logged.

       Debugging  can  also be enabled or disabled by sending a SIGUSR1 signal
       to the pppd process.  This signal acts as a toggle.

EXIT STATUS

       The exit status of pppd is  set  to  indicate  whether  any  error  was
       detected, or the reason for the link being terminated.  The values used
       are:

       0      Pppd has detached, or otherwise the connection was  successfully
              established and terminated at the peer’s request.

       1      An  immediately  fatal  error  of some kind occurred, such as an
              essential system call failing, or running out of virtual memory.

       2      An  error  was detected in processing the options given, such as
              two mutually exclusive options being used.

       3      Pppd is not setuid-root and the invoking user is not root.

       4      The kernel does not support PPP, for  example,  the  PPP  kernel
              driver is not included or cannot be loaded.

       5      Pppd  terminated because it was sent a SIGINT, SIGTERM or SIGHUP
              signal.

       6      The serial port could not be locked.

       7      The serial port could not be opened.

       8      The connect script failed (returned a non-zero exit status).

       9      The command specified as the argument to the  pty  option  could
              not be run.

       10     The  PPP  negotiation failed, that is, it didn’t reach the point
              where at least one network protocol (e.g. IP) was running.

       11     The peer system failed (or refused) to authenticate itself.

       12     The link was established successfully and terminated because  it
              was idle.

       13     The link was established successfully and terminated because the
              connect time limit was reached.

       14     Callback was negotiated  and  an  incoming  call  should  arrive
              shortly.

       15     The  link  was  terminated because the peer is not responding to
              echo requests.

       16     The link was terminated by the modem hanging up.

       17     The PPP negotiation failed because serial loopback was detected.

       18     The init script failed (returned a non-zero exit status).

       19     We failed to authenticate ourselves to the peer.

SCRIPTS

       Pppd  invokes  scripts at various stages in its processing which can be
       used to perform site-specific ancillary processing.  These scripts  are
       usually  shell  scripts,  but  could  be executable code files instead.
       Pppd does not wait for the scripts to finish (except for the  ip-pre-up
       script).  The scripts are executed as root (with the real and effective
       user-id set to 0), so that they can do things such  as  update  routing
       tables  or  run  privileged  daemons.   Be careful that the contents of
       these scripts do not compromise your system’s security.  Pppd runs  the
       scripts  with standard input, output and error redirected to /dev/null,
       and with an environment that  is  empty  except  for  some  environment
       variables  that  give  information  about  the  link.   The environment
       variables that pppd sets are:

       DEVICE The name of the serial tty device being used.

       IFNAME The name of the network interface being used.

       IPLOCAL
              The IP address for the local end of the link.  This is only  set
              when IPCP has come up.

       IPREMOTE
              The IP address for the remote end of the link.  This is only set
              when IPCP has come up.

       PEERNAME
              The authenticated name of the peer.  This is  only  set  if  the
              peer authenticates itself.

       SPEED  The baud rate of the tty device.

       ORIG_UID
              The real user-id of the user who invoked pppd.

       PPPLOGNAME
              The  username  of  the  real  user-id that invoked pppd. This is
              always set.

       For the ip-down and auth-down scripts, pppd  also  sets  the  following
       variables giving statistics for the connection:

       CONNECT_TIME
              The  number  of  seconds  from  when the PPP negotiation started
              until the connection was terminated.

       BYTES_SENT
              The number of bytes sent (at  the  level  of  the  serial  port)
              during the connection.

       BYTES_RCVD
              The  number  of bytes received (at the level of the serial port)
              during the connection.

       LINKNAME
              The logical name of the link, set with the linkname option.

       CALL_FILE
              The value of the call option.

       DNS1   If the peer supplies DNS server addresses, this variable is  set
              to the first DNS server address supplied.

       DNS2   If  the peer supplies DNS server addresses, this variable is set
              to the second DNS server address supplied.

       Pppd invokes the following scripts, if they exist.  It is not an  error
       if they don’t exist.

       /etc/ppp/auth-up
              A  program  or  script which is executed after the remote system
              successfully authenticates itself.   It  is  executed  with  the
              parameters

              interface-name peer-name user-name tty-device speed

              Note  that  this  script  is  not  executed  if the peer doesn’t
              authenticate itself, for example when the noauth option is used.

       /etc/ppp/auth-down
              A  program  or script which is executed when the link goes down,
              if /etc/ppp/auth-up was previously executed.  It is executed  in
              the same manner with the same parameters as /etc/ppp/auth-up.

       /etc/ppp/ip-pre-up
              A  program  or  script  which  is  executed  just before the ppp
              network interface is brought up.  It is executed with  the  same
              parameters  as  the  ip-up  script  (below).   At this point the
              interface exists and has IP  addresses  assigned  but  is  still
              down.   This  can  be  used  to add firewall rules before any IP
              traffic can pass through the interface.  Pppd will wait for this
              script  to  finish  before  bringing  the  interface up, so this
              script should run quickly.

       /etc/ppp/ip-up
              A program or script which is executed when the link is available
              for  sending  and  receiving  IP packets (that is, IPCP has come
              up).  It is executed with the parameters

              interface-name      tty-device      speed       local-IP-address
              remote-IP-address ipparam

       /etc/ppp/ip-down
              A program or script which is executed when the link is no longer
              available for sending and receiving IP packets.  This script can
              be  used  for  undoing  the  effects  of  the /etc/ppp/ip-up and
              /etc/ppp/ip-pre-up scripts.  It is invoked in  the  same  manner
              and with the same parameters as the ip-up script.

       /etc/ppp/ipv6-up
              Like /etc/ppp/ip-up, except that it is executed when the link is
              available for sending and receiving IPv6 packets. It is executed
              with the parameters

              interface-name    tty-device    speed   local-link-local-address
              remote-link-local-address ipparam

       /etc/ppp/ipv6-down
              Similar to  /etc/ppp/ip-down,  but  it  is  executed  when  IPv6
              packets can no longer be transmitted on the link. It is executed
              with the same parameters as the ipv6-up script.

       /etc/ppp/ipx-up
              A program or script which is executed when the link is available
              for  sending  and receiving IPX packets (that is, IPXCP has come
              up).  It is executed with the parameters

              interface-name       tty-device       speed       network-number
              local-IPX-node-address                   remote-IPX-node-address
              local-IPX-routing-protocol           remote-IPX-routing-protocol
              local-IPX-router-name remote-IPX-router-name ipparam pppd-pid

              The  local-IPX-routing-protocol  and remote-IPX-routing-protocol
              field may be one of the following:

              NONE      to indicate that there is no routing protocol
              RIP       to indicate that RIP/SAP should be used
              NLSP      to indicate that Novell NLSP should be used
              RIP NLSP  to indicate that both RIP/SAP and NLSP should be used

       /etc/ppp/ipx-down
              A program or script which is executed when the link is no longer
              available  for  sending  and receiving IPX packets.  This script
              can be used for  undoing  the  effects  of  the  /etc/ppp/ipx-up
              script.   It  is  invoked  in  the same manner and with the same
              parameters as the ipx-up script.

FILES

       /var/run/pppn.pid (BSD or Linux), /etc/ppp/pppn.pid (others)
              Process-ID for pppd process on ppp interface unit n.

       /var/run/ppp-name.pid (BSD or Linux),
              /etc/ppp/ppp-name.pid (others) Process-ID for pppd  process  for
              logical link name (see the linkname option).

       /var/run/pppd2.tdb
              Database containing information about pppd processes, interfaces
              and links, used for  matching  links  to  bundles  in  multilink
              operation.   May  be  examined  by  external  programs to obtain
              information about running pppd  instances,  the  interfaces  and
              devices   they   are   using,   IP   address  assignments,  etc.
              /etc/ppp/pap-secrets Usernames, passwords and IP  addresses  for
              PAP  authentication.   This file should be owned by root and not
              readable or writable by any other user.  Pppd will log a warning
              if this is not the case.

       /etc/ppp/chap-secrets
              Names,  secrets  and  IP  addresses  for  CHAP/MS-CHAP/MS-CHAPv2
              authentication.  As for /etc/ppp/pap-secrets, this  file  should
              be owned by root and not readable or writable by any other user.
              Pppd will log a warning if this is not the case.

       /etc/ppp/srp-secrets
              Names, secrets, and IP addresses for EAP authentication.  As for
              /etc/ppp/pap-secrets,  this file should be owned by root and not
              readable or writable by any other user.  Pppd will log a warning
              if this is not the case.

       ~/.ppp_pseudonym
              Saved client-side SRP-SHA1 pseudonym.  See the srp-use-pseudonym
              option for details.

       /etc/ppp/options
              System default  options  for  pppd,  read  before  user  default
              options or command-line options.

       ~/.ppprc
              User default options, read before /etc/ppp/options.ttyname.

       /etc/ppp/options.ttyname
              System  default  options  for  the  serial port being used, read
              after ~/.ppprc.  In forming the ttyname part of  this  filename,
              an  initial  /dev/  is stripped from the port name (if present),
              and any slashes in the remaining part are converted to dots.

       /etc/ppp/peers
              A  directory  containing  options  files   which   may   contain
              privileged  options,  even  if  pppd was invoked by a user other
              than root.  The system administrator can create options files in
              this  directory  to  permit  non-privileged  users  to  dial out
              without requiring the peer to authenticate, but only to  certain
              trusted peers.

SEE ALSO

       chat(8), pppstats(8)

       RFC1144
              Jacobson,  V.   Compressing  TCP/IP headers for low-speed serial
              links.  February 1990.

       RFC1321
              Rivest, R.  The MD5 Message-Digest Algorithm.  April 1992.

       RFC1332
              McGregor, G.  PPP Internet  Protocol  Control  Protocol  (IPCP).
              May 1992.

       RFC1334
              Lloyd, B.; Simpson, W.A.  PPP authentication protocols.  October
              1992.

       RFC1661
              Simpson, W.A.  The Point-to-Point Protocol (PPP).  July 1994.

       RFC1662
              Simpson, W.A.  PPP in HDLC-like Framing.  July 1994.

       RFC2284
              Blunk,  L.;  Vollbrecht,  J.,  PPP   Extensible   Authentication
              Protocol (EAP).  March 1998.

       RFC2472
              Haskin, D.  IP Version 6 over PPP December 1998.

       RFC2945
              Wu, T., The SRP Authentication and Key Exchange System September
              2000.

       draft-ietf-pppext-eap-srp-03.txt
              Carlson, J.; et al., EAP SRP-SHA1 Authentication Protocol.  July
              2001.

NOTES

       Some  limited  degree  of  control can be exercised over a running pppd
       process by sending it a signal from the list below.

       SIGINT, SIGTERM
              These signals cause pppd to terminate the link (by closing LCP),
              restore the serial device settings, and exit.  If a connector or
              disconnector process is currently running, pppd  will  send  the
              same  signal  to  its  process  group,  so  as  to terminate the
              connector or disconnector process.

       SIGHUP This signal causes pppd  to  terminate  the  link,  restore  the
              serial  device  settings,  and  close the serial device.  If the
              persist or demand option has been specified, pppd  will  try  to
              reopen the serial device and start another connection (after the
              holdoff period).  Otherwise pppd will exit.  If this  signal  is
              received  during  the  holdoff period, it causes pppd to end the
              holdoff period immediately.   If  a  connector  or  disconnector
              process  is  running,  pppd  will  send  the  same signal to its
              process group.

       SIGUSR1
              This signal toggles the state of the debug option.

       SIGUSR2
              This signal causes pppd to renegotiate compression.  This can be
              useful  to re-enable compression after it has been disabled as a
              result of a fatal  decompression  error.   (Fatal  decompression
              errors generally indicate a bug in one or other implementation.)

AUTHORS

       Paul Mackerras  (paulus@samba.org),  based  on  earlier  work  by  Drew
       Perkins, Brad Clements, Karl Fox, Greg Christy, and Brad Parker.

COPYRIGHT

       Pppd  is  copyrighted and made available under conditions which provide
       that it may be copied and used in source or binary forms provided  that
       the  conditions  listed below are met.  Portions of pppd are covered by
       the following copyright notices:

       Copyright  (c)  1984-2000  Carnegie  Mellon  University.   All   rights
       reserved.
       Copyright (c) 1993-2004 Paul Mackerras. All rights reserved.
       Copyright (c) 1995 Pedro Roque Marques.  All rights reserved.
       Copyright (c) 1995 Eric Rosenquist.  All rights reserved.
       Copyright (c) 1999 Tommi Komulainen.  All rights reserved.
       Copyright (C) Andrew Tridgell 1999
       Copyright (c) 2000 by Sun Microsystems, Inc.  All rights reserved.
       Copyright (c) 2001 by Sun Microsystems, Inc.  All rights reserved.
       Copyright (c) 2002 Google, Inc.  All rights reserved.

       The copyright notices contain the following statements.

       Redistribution  and  use  in  source  and binary forms, with or without
       modification, are permitted provided that the following conditions  are
       met:

       1. Redistributions of source code must retain the above copyright
          notice, this list of conditions and the following disclaimer.

       2. Redistributions in binary form must reproduce the above copyright
          notice, this list of conditions and the following disclaimer in
          the documentation and/or other materials provided with the
          distribution.

       3. The name "Carnegie Mellon University" must not be used to
          endorse or promote products derived from this software without
          prior written permission. For permission or any legal
          details, please contact
            Office of Technology Transfer
            Carnegie Mellon University
            5000 Forbes Avenue
            Pittsburgh, PA  15213-3890
            (412) 268-4387, fax: (412) 268-7395
            tech-transfer@andrew.cmu.edu

       3b. The name(s) of the authors of this software must not be used to
          endorse or promote products derived from this software without
          prior written permission.

       4. Redistributions of any form whatsoever must retain the following
          acknowledgments:
          "This product includes software developed by Computing Services
           at Carnegie Mellon University (http://www.cmu.edu/computing/)."
          "This product includes software developed by Paul Mackerras
           <paulus@samba.org>".
          "This product includes software developed by Pedro Roque Marques
           <pedro_m@yahoo.com>".
          "This product includes software developed by Tommi Komulainen
           <Tommi.Komulainen@iki.fi>".

       CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
       SOFTWARE, INCLUDING  ALL  IMPLIED  WARRANTIES  OF  MERCHANTABILITY  AND
       FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE FOR ANY
       SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR  ANY  DAMAGES  WHATSOEVER
       RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
       CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING  OUT  OF  OR  IN
       CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

       THE  AUTHORS  OF  THIS  SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
       THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY  AND
       FITNESS,  IN  NO  EVENT  SHALL  THE  AUTHORS BE LIABLE FOR ANY SPECIAL,
       INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES  WHATSOEVER  RESULTING
       FROM  LOSS  OF  USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
       NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF  OR  IN  CONNECTION
       WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

                                                                       PPPD(8)