PPP(8) PPP(8)
NAME
ppp, pppoe, pptp, pptpd - point-to-point protocol
SYNOPSIS
ip/ppp [ -CPSacdfu ] [ -b baud ] [ -k keyspec ] [ -m mtu ] [
-M chatfile ] [ -p dev ] [ -x netmntpt ] [ -t modemcmd ] [
local [ remote ] ]
ip/pppoe [ -Pd ] [ -A acname ] [ -S srvname ] [ -k keyspec ]
[ -m mtu ] [ -x pppnetmntpt ] [ ether ]
ip/pptp [ -dP ] [ -k keyspec ] [ -w window ] [ -x
pppnetmntpt ] server
ip/pptpd [ -d ] [ -p pppnetmtpt ] [ -w window ] [ -D
fraction ] tcp-dir
DESCRIPTION
The Point-to-Point Protocol is used to encapsulate Internet
Protocol packets in IPv4 packets for transfer over serial
lines or other protocol connections. Ppp can run either as
a client or, with the -S option, as a server. The only dif-
ferences between a client and a server is that the server
will not believe any local address the client tries to sup-
ply it and that the server always initiates the authentica-
tion of the client.
With no option, ppp communicates with the remote system via
standard input and output. This is useful if a program
wants to use ppp in a communications stream. However, the
normal mode is to specify a communications device, usually a
serial line with a modem.
Ppp supports the following options:
a as server, don't request authentication from the client
b set the baud rate on the communications device
c disallow packet compression
C disallow IP header compression
f make PPP add HDLC framing. This is necessary when using
PPP over a serial line or a TCP connection
k add keyspec to the factotum(4) key pattern when looking
for a user name and password for authentication; the
default key pattern is proto=pass service=ppp
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PPP(8) PPP(8)
m set the maximum transfer unit (default 1450)
M chat with the modem as specified in the chat file. Each
line in the chat file contains a string that is transmit-
ted to the modem and the response expected (e.g. 'AT'
'OK')
P use this as the primary IP interface; set the default
route through this interface and write its configuration
to /net/ndb
p communicate over dev instead of standard I/O
S run as a server
t before starting the PPP protocol, write modemcmd to the
device
u before starting the PPP protocol with the remote end,
shuttle bytes between the device and standard I/O until
an EOF on standard input. This allows a user to start
ppp and then type commands at a modem before ppp takes
over
x use the IP stack mounted at netmntpt
If both the local and remote addresses are specified, don't
ask the other end for either or believe it if it supplies
one. If either is missing, get it from the remote end.
Pppoe is a PPP over ethernet (PPPoE) client. It invokes ppp
to start a PPP conversation which is tunneled in PPPoE pack-
ets on the ethernet device mounted at etherdir (default
/net/ether0). The pppoe-specific options are:
A insist on an access concentrator named acname during
PPPoE discovery
d write debugging output to standard error, and pass -d to
ppp
S insist on a service named srvname during PPPoE discovery
The other options are relayed to ppp.
Pptp is a client for a PPTP encrypted tunnel. Server is the
name of the server to dial. Pptp takes the same options as
pppoe, except for the lack of a -m option and the addition
of a -w option. The -w option specifies the local send win-
dow size (default 16) in packets.
Pptpd is the server side of a PPTP encrypted tunnel. Tcpdir
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PPP(8) PPP(8)
is the directory of a TCP connection to the client. The TCP
connection is used to control the tunnel while packets are
sent back and forth using PPP inside of GRE packets. The
options are:
d write debugging output to standard error.
D drop fraction of the received packets. This is used for
testing.
p use the IP stack mounted at pppnetmtpt to terminate the
PPP connection.
w set the receive window to window.
SOURCE
/sys/src/cmd/ip/ppp
/sys/src/cmd/ip/pptpd.c
/sys/src/cmd/ip/pppoe.c
SEE ALSO
gre in ip(3)
BUGS
Ppp should use factotum to execute the client side of the
challenge-reponse protocol, but instead it reads a password
from factotum and runs the protocol itself.
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