Provided by: pptp-linux_1.10.0-1build3_amd64 bug


       pptp - PPTP driver


       pptp <pptp-server-IP> <pptp-options> [ppp-options] ...


       pptp  establishes  the  client side of a Virtual Private Network (VPN) using the Point-to-
       Point Tunneling Protocol (PPTP).  Use this program to connect to an employer's PPTP  based
       VPN, or to certain cable and ADSL service providers.

       By default, pptp establishes the PPTP call to the PPTP server, and then starts an instance
       of pppd to manage the data transfer.  However, pptp  can  also  be  run  as  a  connection
       manager within pppd.


       The first non-option argument on the pptp command line must be the host name or IP address
       of the PPTP server.

       All long options (starting with "--") are interpreted as pptp options, and a  fatal  error
       occurs if an unrecognised option is used.

       All command-line arguments which do not start with "-" are interpreted as ppp options, and
       passed as is to pppd unless --nolaunchpppd is given.

       --phone <number>
              Pass <number> to remote host as phone number

              Do not launch pppd but use stdin as the network connection.   Use  this  flag  when
              including pptp as a pppd connection process using the pty option.  See EXAMPLES.

       --quirks <quirk>
              Work  around  a  buggy  PPTP  implementation,  adopts  special  case  handling  for
              particular  PPTP  servers  and  ADSL  modems.   Currently  recognised  values   are
              BEZEQ_ISRAEL only

              Run in foreground (for debugging with gdb)

       --sync Enable Synchronous HDLC (pppd must use it too)

       --timeout <secs>
              Time to wait for reordered packets (0.01 to 10 secs)

              Completely  disables  buffering and reordering of packets.  Any --timeout specified
              will be ignored.

       --idle-wait <secs>
              Time to wait before sending a control connection echo request.  The RFC2637 default
              is 60 seconds.

       --max-echo-wait <secs>
              Time  to wait for an echo reply before closing the control connection.  The RFC2637
              default is 60 seconds.

       --logstring <name>
              Use <name> instead of 'anon' in syslog messages

       --localbind <addr>
              Bind to specified IP address instead of wildcard

       --rtmark <n>
              Use specified policy routing mark for  all  packets.   This  causes  both  the  TCP
              control  connection's  packets  as well as the GRE packets to bear the given policy
              routing / netfilter mark. This can be used with ip rule (from iproute2)  to  use  a
              separate routing table for the pptp client.

              (requires root privileges or the CAP_NET_ADMIN capability.)

              Do  not  configure  a  host  route  pointing towards the PPTP server.  (cf. ROUTING

       --loglevel <level>
              Sets the debugging level (0=low, 1=default, 2=high)

       --test-type <n>
              Enable packet reordering tests that damage the integrity of the  packet  stream  to
              the  server.   Use  this only when testing servers.  Zero is the default, and means
              that packets are sent in the correct order.  A value of one  (1)  causes  a  single
              swap  between  two packets, such that the sequence numbers might be 1 2 3 4 6 5 7 8
              9.  A value of two (2) causes ten packets to be buffered, then sent  out  of  order
              but  ascending, such that the sequence numbers might be 1 2 3 4 16 6 7 8 9 10 11 12
              13 14 15 17 18 19 20.  A value of three (3) causes ten packets to be buffered, then
              sent  in the reverse order, like this; 1 2 3 4 16 15 14 13 12 11 10 9 8 7 6 5 17 18
              19 20.

       --test-rate <n>
              Sets the number of packets to pass before causing a reordering  test.   Default  is
              100.   Has  no  effect  if test-type is zero.  The result of test types 2 and 3 are
              undefined if this value is less than ten.


       When PPTP is used in conjunction with a default route on top of the tunnel  (or  just  any
       route encompassing the PPTP server), the mechanics of routing would cause the PPTP packets
       themselves to be routed over the tunnel. This  would  result  in  an  encapsulation  loop,
       destroying connectivity.

       pptp  by  default  works  around  this  by looking up the route towards the PPTP server at
       startup and configures a host route with that data.  This  essentially  "freezes"  routing
       for  PPTP  packets  at  the  startup  configuration.  This  behaviour can be disabled with
       --nohostroute if undesired (like when using --rtmark to implement policy routing).

       NB: the route added by pptp is currently not deleted at exit!


              modifies packets to interoperate with Orckit ADSL modems on the  BEZEQ  network  in


       Connection to a Microsoft Windows VPN Server

         pppd noauth nobsdcomp nodeflate require-mppe-128 name domain\\\\username remotename PPTP
       pty "pptp --nolaunchpppd"

       Note that the chap-secrets file used by pppd must include an entry for domain\\username


       The pptp process collects statistics when sending and  receiving  GRE  packets.  They  are
       intended  to  be  useful for debugging poor PPTP performance and for general monitoring of
       link quality. The statistics are cumulative since the pptp process was started.

       The statistics can be viewed by sending a  SIGUSR1  signal  to  the  "GRE-to-PPP  Gateway"
       process,  which will cause it to dump them to the system logs (at the LOG_NOTICE level). A
       better way to present the statistics to applications is being sought (e.g. SNMP?).

       The following statistics are collected at the time of writing (April 2003):

       rx accepted
              the number of GRE packets successfully passed to PPP

       rx lost
              the number of packets never received, and presumed lost in the network

       rx under win
              the number of packets which were duplicates or had old sequence numbers (this might
              be caused by a packet-reordering network if your reordering timeout is set too low)

       rx over win
              the  number  of  packets  which  were too far ahead in the sequence to be reordered
              (might be caused by loss of more than 300 packets in a row)

       rx buffered
              the number of packets which were  slightly  ahead  of  sequence,  and  were  either
              buffered  for  reordering,  or  if  buffering  is  disabled,  accepted  immediately
              (resulting in the intermediate packets being discarded).

       rx OS errors
              the number of times where the operating system reported an error when we  tried  to
              read a packet

       rx truncated
              the  number of times we received a packet which was shorter than the length implied
              by the GRE header

       rx invalid
              the number of times we received a packet which had invalid or unsupported flags set
              in the header, wrong version, or wrong protocol.

       rx acks
              the number of pure acknowledgements received (without data). Too many of these will
              waste bandwidth, and might be solved by tuning the remote host.

       tx sent
              the number of GRE packets sent with data

       tx failed
              the number of packets we tried to send, but the OS reported an error

       tx short
              the number of times the OS would not let us write a complete packet

       tx acks
              the number of times we sent a pure ack, without data

       tx oversize
              the number of times we couldn't send a packet because it was over PACKET_MAX  bytes

       round trip
              the estimated round-trip time in milliseconds



       Documentation in /usr/share/doc/pptp-linux


       This manual page was written by James Cameron <> from text contributed
       by Thomas Quinot <>, for the Debian GNU/Linux system.  The description of
       the available statistics was written by Chris Wilson <>. Updates for
       the Debian distribution by Ola Lundqvist <>.