1PPTP(8)                     System Manager's Manual                    PPTP(8)
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NAME

6       pptp - PPTP driver
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SYNOPSIS

9       pptp <pptp-server-IP> <pptp-options> [ppp-options] ...
10

DESCRIPTION

12       pptp  establishes  the  client  side of a Virtual Private Network (VPN)
13       using the Point-to-Point Tunneling Protocol (PPTP).  Use  this  program
14       to  connect  to  an  employer's PPTP based VPN, or to certain cable and
15       ADSL service providers.
16
17       By default, pptp establishes the PPTP call to the PPTP server, and then
18       starts  an instance of pppd to manage the data transfer.  However, pptp
19       can also be run as a connection manager within pppd.
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OPTIONS

22       The first non-option argument on the pptp command line must be the host
23       name or IP address of the PPTP server.
24
25       All  long options (starting with "--") are interpreted as pptp options,
26       and a fatal error occurs if an unrecognised option is used.
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28       All command-line arguments which do not start with "-" are  interpreted
29       as  ppp  options,  and  passed  as  is to pppd unless --nolaunchpppd is
30       given.
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32       --phone <number>
33              Pass <number> to remote host as phone number
34
35       --nolaunchpppd
36              Do not launch pppd but use stdin as the network connection.  Use
37              this flag when including pptp as a pppd connection process using
38              the pty option.  See EXAMPLES.
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40       --quirks <quirk>
41              Work around a buggy PPTP  implementation,  adopts  special  case
42              handling for particular PPTP servers and ADSL modems.  Currently
43              recognised values are BEZEQ_ISRAEL only
44
45       --debug
46              Run in foreground (for debugging with gdb)
47
48       --sync Enable Synchronous HDLC (pppd must use it too)
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50       --timeout <secs>
51              Time to wait for reordered packets (0.01 to 10 secs)
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53       --nobuffer
54              Completely disables buffering and reordering  of  packets.   Any
55              --timeout specified will be ignored.
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57       --idle-wait <secs>
58              Time  to  wait before sending a control connection echo request.
59              The RFC2637 default is 60 seconds.
60
61       --max-echo-wait <secs>
62              Time to wait for an echo reply before closing the  control  con‐
63              nection.  The RFC2637 default is 60 seconds.
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65       --logstring <name>
66              Use <name> instead of 'anon' in syslog messages
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68       --localbind <addr>
69              Bind to specified IP address instead of wildcard
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71       --rtmark <n>
72              Use  specified policy routing mark for all packets.  This causes
73              both the TCP control connection's packets as  well  as  the  GRE
74              packets  to bear the given policy routing / netfilter mark. This
75              can be used with ip rule (from iproute2) to use a separate rout‐
76              ing table for the pptp client.
77
78              (requires root privileges or the CAP_NET_ADMIN capability.)
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80       --nohostroute
81              Do  not configure a host route pointing towards the PPTP server.
82              (cf. ROUTING below)
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84
85       --loglevel <level>
86              Sets the debugging level (0=low, 1=default, 2=high)
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88
89       --test-type <n>
90              Enable packet reordering tests that damage the integrity of  the
91              packet  stream  to  the  server.   Use  this  only  when testing
92              servers.  Zero is the default, and means that packets  are  sent
93              in  the  correct order.  A value of one (1) causes a single swap
94              between two packets, such that the sequence numbers might be 1 2
95              3  4  6  5  7  8 9.  A value of two (2) causes ten packets to be
96              buffered, then sent out of order but ascending,  such  that  the
97              sequence  numbers  might be 1 2 3 4 16 6 7 8 9 10 11 12 13 14 15
98              17 18 19 20.  A value of three (3)  causes  ten  packets  to  be
99              buffered,  then sent in the reverse order, like this; 1 2 3 4 16
100              15 14 13 12 11 10 9 8 7 6 5 17 18 19 20.
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102
103       --test-rate <n>
104              Sets the number of packets to pass before causing  a  reordering
105              test.  Default is 100.  Has no effect if test-type is zero.  The
106              result of test types 2 and 3 are undefined if this value is less
107              than ten.
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ROUTING

112       When  PPTP  is  used  in conjunction with a default route on top of the
113       tunnel (or just any route encompassing the PPTP server), the  mechanics
114       of  routing  would  cause the PPTP packets themselves to be routed over
115       the tunnel. This would result in an encapsulation loop, destroying con‐
116       nectivity.
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118       pptp  by  default works around this by looking up the route towards the
119       PPTP server at startup and configures a  host  route  with  that  data.
120       This essentially "freezes" routing for PPTP packets at the startup con‐
121       figuration. This behaviour can be disabled with --nohostroute if  unde‐
122       sired (like when using --rtmark to implement policy routing).
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124       NB: the route added by pptp is currently not deleted at exit!
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126

QUIRKS

128       BEZEQ_ISRAEL
129              modifies  packets to interoperate with Orckit ADSL modems on the
130              BEZEQ network in Israel.
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132

EXAMPLES

134       Connection to a Microsoft Windows VPN Server
135
136        pppd noauth nobsdcomp nodeflate require-mppe-128 name  domain\\\\user‐
137       name remotename PPTP pty "pptp 10.0.0.5 --nolaunchpppd"
138
139       Note  that the chap-secrets file used by pppd must include an entry for
140       domain\\username
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STATISTICS

144       The pptp process collects statistics when  sending  and  receiving  GRE
145       packets. They are intended to be useful for debugging poor PPTP perfor‐
146       mance and for general monitoring of link quality.  The  statistics  are
147       cumulative since the pptp process was started.
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149       The  statistics  can be viewed by sending a SIGUSR1 signal to the "GRE-
150       to-PPP Gateway" process, which will cause it to dump them to the system
151       logs  (at the LOG_NOTICE level). A better way to present the statistics
152       to applications is being sought (e.g. SNMP?).
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154       The following statistics are collected at the time  of  writing  (April
155       2003):
156
157       rx accepted
158              the number of GRE packets successfully passed to PPP
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160       rx lost
161              the  number  of packets never received, and presumed lost in the
162              network
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164       rx under win
165              the number of packets which were duplicates or had old  sequence
166              numbers  (this might be caused by a packet-reordering network if
167              your reordering timeout is set too low)
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169       rx over win
170              the number of packets which were too far ahead in  the  sequence
171              to  be reordered (might be caused by loss of more than 300 pack‐
172              ets in a row)
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174       rx buffered
175              the number of packets which were slightly ahead of sequence, and
176              were  either  buffered  for  reordering, or if buffering is dis‐
177              abled, accepted immediately (resulting in the intermediate pack‐
178              ets being discarded).
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180       rx OS errors
181              the number of times where the operating system reported an error
182              when we tried to read a packet
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184       rx truncated
185              the number of times we received a packet which was shorter  than
186              the length implied by the GRE header
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188       rx invalid
189              the  number  of  times we received a packet which had invalid or
190              unsupported flags set in the header,  wrong  version,  or  wrong
191              protocol.
192
193       rx acks
194              the number of pure acknowledgements received (without data). Too
195              many of these will waste bandwidth, and might be solved by  tun‐
196              ing the remote host.
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198       tx sent
199              the number of GRE packets sent with data
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201       tx failed
202              the  number  of packets we tried to send, but the OS reported an
203              error
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205       tx short
206              the number of times the OS would not let  us  write  a  complete
207              packet
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209       tx acks
210              the number of times we sent a pure ack, without data
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212       tx oversize
213              the  number  of  times  we couldn't send a packet because it was
214              over PACKET_MAX bytes long
215
216       round trip
217              the estimated round-trip time in milliseconds
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SEE ALSO

221       pppd(8)
222
223       Documentation in /usr/share/doc/pptp
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AUTHOR

226       This manual page was written by  James  Cameron  <james.cameron@hp.com>
227       from  text  contributed  by  Thomas Quinot <thomas@debian.org>, for the
228       Debian GNU/Linux system.  The description of the  available  statistics
229       was  written  by Chris Wilson <chris@netservers.co.uk>. Updates for the
230       Debian distribution by Ola Lundqvist <opal@debian.org>.
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