pppd.8

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

.TP
.B 4
The kernel does not support PPP, for example, the PPP kernel driver is
not included or cannot be loaded.
.TP
.B 5
Pppd terminated because it was sent a SIGINT, SIGTERM or SIGHUP
signal.
.TP
.B 6
The serial port could not be locked.
.TP
.B 7
The serial port could not be opened.
.TP
.B 8
The connect script failed (returned a non-zero exit status).
.TP
.B 9
The command specified as the argument to the \fIpty\fR option could
not be run.
.TP
.B 10
The PPP negotiation failed, that is, it didn't reach the point where
at least one network protocol (e.g. IP) was running.
.TP
.B 11
The peer system failed (or refused) to authenticate itself.
.TP
.B 12
The link was established successfully and terminated because it was
idle.
.TP
.B 13
The link was established successfully and terminated because the
connect time limit was reached.
.TP
.B 14
Callback was negotiated and an incoming call should arrive shortly.
.TP
.B 15
The link was terminated because the peer is not responding to echo
requests.
.TP
.B 16
The link was terminated by the modem hanging up.
.TP
.B 17
The PPP negotiation failed because serial loopback was detected.
.TP
.B 18
The init script failed (returned a non-zero exit status).
.TP
.B 19
We failed to authenticate ourselves to the peer.
.SH 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.  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:
.TP
.B DEVICE
The name of the serial tty device being used.
.TP
.B IFNAME
The name of the network interface being used.
.TP
.B IPLOCAL
The IP address for the local end of the link.  This is only set when
IPCP has come up.
.TP
.B IPREMOTE
The IP address for the remote end of the link.  This is only set when
IPCP has come up.
.TP
.B PEERNAME
The authenticated name of the peer.  This is only set if the peer
authenticates itself.
.TP
.B SPEED
The baud rate of the tty device.
.TP
.B ORIG_UID
The real user-id of the user who invoked pppd.
.TP
.B PPPLOGNAME
The username of the real user-id that invoked pppd. This is always set.
.P
For the ip-down and auth-down scripts, pppd also sets the following
variables giving statistics for the connection:
.TP
.B CONNECT_TIME
The number of seconds from when the PPP negotiation started until the
connection was terminated.
.TP
.B BYTES_SENT
The number of bytes sent (at the level of the serial port) during the
connection.
.TP
.B BYTES_RCVD
The number of bytes received (at the level of the serial port) during
the connection.
.TP
.B LINKNAME
The logical name of the link, set with the \fIlinkname\fR option.
.P
Pppd invokes the following scripts, if they exist.  It is not an error
if they don't exist.
.TP
.B /etc/ppp/auth-up
A program or script which is executed after the remote system
successfully authenticates itself.  It is executed with the parameters
.IP
\fIinterface-name peer-name user-name tty-device speed\fR
.IP
Note that this script is not executed if the peer doesn't authenticate
itself, for example when the \fInoauth\fR option is used.
.TP
.B /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.
.TP
.B /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
.IP
\fIinterface-name tty-device speed local-IP-address
remote-IP-address ipparam\fR
.TP
.B /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 script.  It is
invoked in the same manner and with the same parameters as the ip-up
script.
.TP
.B /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
.IP
\fIinterface-name tty-device speed local-link-local-address
remote-link-local-address ipparam\fR
.TP
.B /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.
.TP
.B /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
.IP
\fIinterface-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\fR 
.IP
The local-IPX-routing-protocol and remote-IPX-routing-protocol field
may be one of the following:
.IP
NONE      to indicate that there is no routing protocol
.br
RIP       to indicate that RIP/SAP should be used
.br
NLSP      to indicate that Novell NLSP should be used
.br
RIP NLSP  to indicate that both RIP/SAP and NLSP should be used
.TP
.B /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.
.SH FILES
.TP
.B /var/run/ppp\fIn\fB.pid \fR(BSD or Linux), \fB/etc/ppp/ppp\fIn\fB.pid \fR(others)
Process-ID for pppd process on ppp interface unit \fIn\fR.
.TP
.B /var/run/ppp-\fIname\fB.pid \fR(BSD or Linux), \fB/etc/ppp/ppp-\fIname\fB.pid \fR(others)
Process-ID for pppd process for logical link \fIname\fR (see the
\fIlinkname\fR option).
.TP
.B /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.
.TP
.B /etc/ppp/chap-secrets
Names, secrets and IP addresses for CHAP 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.
.TP
.B /etc/ppp/options
System default options for pppd, read before user default options or
command-line options.
.TP
.B ~/.ppprc
User default options, read before /etc/ppp/options.\fIttyname\fR.
.TP
.B /etc/ppp/options.\fIttyname
System default options for the serial port being used, read after
~/.ppprc.  In forming the \fIttyname\fR 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.
.TP
.B /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.
.SH SEE ALSO
.TP
.B RFC1144
Jacobson, V.
\fICompressing TCP/IP headers for low-speed serial links.\fR
February 1990.
.TP
.B RFC1321
Rivest, R.
.I The MD5 Message-Digest Algorithm.
April 1992.
.TP
.B RFC1332
McGregor, G.
.I PPP Internet Protocol Control Protocol (IPCP).
May 1992.
.TP
.B RFC1334
Lloyd, B.; Simpson, W.A.
.I PPP authentication protocols.
October 1992.
.TP
.B RFC1661
Simpson, W.A.
.I The Point\-to\-Point Protocol (PPP).
July 1994.
.TP
.B RFC1662
Simpson, W.A.
.I PPP in HDLC-like Framing.
July 1994.
.TP
.B RFC2472
Haskin, D.
.I IP Version 6 over PPP
December 1998.
.SH NOTES
The following signals have the specified effect when sent to pppd.
.TP
.B SIGINT, SIGTERM
These signals cause pppd to terminate the link (by closing LCP),
restore the serial device settings, and exit.
.TP
.B SIGHUP
This signal causes pppd to terminate the link, restore the serial
device settings, and close the serial device.  If the \fIpersist\fR or
\fIdemand\fR 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.
.TP
.B SIGUSR1
This signal toggles the state of the \fIdebug\fR option.
.TP
.B 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.)

.SH AUTHORS
Paul Mackerras ([e-mail]), based on earlier work by
Drew Perkins,
Brad Clements,
Karl Fox,
Greg Christy,
and
Brad Parker.