PPP problem : Serial line is looped back ??
jerome fayot
I have setup my work machine for incoming PPP connections via IP
masquerade. All is fine !
I want now to setup a callback system on my work machine to connect from
home with PPP and IP masquerade, and save phone bills ;-)
Before I start using callback package, I want to be sure I can connect
to my home Linux box from work, using PPP.
So, I first setup my home machine for incoming PPP connections, and
tried to connect from work. Chat goes fine, but when starting ppp, I get
the following message from /var/log/messages :
Feb 22 19:54:44 workmachine pppd[16818]: Serial connection established.
Feb 22 19:54:45 workmachine pppd[16818]: Using interface ppp0
Feb 22 19:54:45 workmachine pppd[16818]: Connect: ppp0 <--> /dev/ttyS0
Feb 22 19:54:45 workmachine pppd[16818]: Serial line is looped back.
Feb 22 19:54:45 workmachine pppd[16818]: Connection terminated.
Feb 22 19:54:46 workmachine pppd[16818]: Exit.
Can someone help me ?
Thanks
Phil Burden
>to my home Linux box from work, using PPP.
>
>So, I first setup my home machine for incoming PPP connections, and
>tried to connect from work. Chat goes fine, but when starting ppp, I get
>the following message from /var/log/messages :
>
>Feb 22 19:54:44 workmachine pppd[16818]: Serial connection established.
>Feb 22 19:54:45 workmachine pppd[16818]: Using interface ppp0
>Feb 22 19:54:45 workmachine pppd[16818]: Connect: ppp0 <--> /dev/ttyS0
>Feb 22 19:54:45 workmachine pppd[16818]: Serial line is looped back.
I'm no expoert, far from it, but I had the same error and it was pointed out
to me that essentially, the modem has reverted, or is still in, command
mode. It iturned out to be a timeout problem, PPP wasn't waiting long enough
for the correct response from the modem. Hope that helps a little, I cured
it by using different scripts I found in the how-to's.
P.
ku...@mindspring.com
took care of it. Seems like when the modem is echoing, pppd thinks
its looped back.
On Mon, 22 Feb 1999 20:19:05 +0100, jerome fayot <j...@lpnhp2.in2p3.fr>
wrote:
>This is a multi-part message in MIME format.
>--------------0D100F500E364F099708388C
>Content-Type: text/plain; charset=us-ascii
>Content-Transfer-Encoding: 7bit
>
>I have two Linux boxes : one at home, and one at work.
>
>I have setup my work machine for incoming PPP connections via IP
>masquerade. All is fine !
>
>I want now to setup a callback system on my work machine to connect from
>home with PPP and IP masquerade, and save phone bills ;-)
>
>Before I start using callback package, I want to be sure I can connect
>to my home Linux box from work, using PPP.
>
>So, I first setup my home machine for incoming PPP connections, and
>tried to connect from work. Chat goes fine, but when starting ppp, I get
>the following message from /var/log/messages :
>
>Feb 22 19:54:44 workmachine pppd[16818]: Serial connection established.
>Feb 22 19:54:45 workmachine pppd[16818]: Using interface ppp0
>Feb 22 19:54:45 workmachine pppd[16818]: Connect: ppp0 <--> /dev/ttyS0
>Feb 22 19:54:45 workmachine pppd[16818]: Serial line is looped back.
>Feb 22 19:54:45 workmachine pppd[16818]: Connection terminated.
>Feb 22 19:54:46 workmachine pppd[16818]: Exit.
>
>Can someone help me ?
>Thanks
>
>
>
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>--------------0D100F500E364F099708388C--
>
Bernd Harries
> I'm using Linux Kernel 2.2.0 and PPPD 2.3.5f.
Good.
You want to dial into your school, right? And you have Linux.
But obviously not Debian Linux? Pitty, really.
Anyway, I would say don't use dip. Forget dip. Read the pppd and
the chat manpages intensively.
Use 'pppd call school'
Have a file /etc/ppp/peers/school like the /etc/ppp/options,
but with only THE pppd-options specific for your school.
Especially connect "/usr/sbin/chat -v -f
/etc/chatscripts/chatscript_school"
and the user kurtk
Have a pap-secrets file ready or if you have to login before pppd talks,
modify the chatscript similar to dip. (man chat)
Below are the files for my Provider in germany.
Change the specifig things to your needs:
phone-number, speed, port, (username, password)
Post the xconsole output or the /var/log/ppp.log tail if still problems.
Keep me updated.
----------------------------------------------
The chatscript
----------------------------------------------
ABORT "NO DIALTONE"
ABORT "NO CARRIER"
ABORT ERROR
ABORT VOICE
"" ATZ1
OK ATb8
ABORT BUSY
OK ATD042153763
CONNECT ""
----------------------------------------------
The peer-specific options
----------------------------------------------
# /etc/ppp/options
#
# $Id: options,v 1.4 1996/05/01 18:57:04 alvar Exp $
#
# Originally created by Jim Knoble <jmkn...@mercury.interpath.net>
# Modified for Debian by alvar Bray <al...@meiko.co.uk>
# Modified for PPP Server setup by Christoph Lameter
<clam...@debian.org>
#
# Use the command egrep -v '#|^ *$' /etc/ppp/options to quickly see
what
# options are active in this file.
# Specify which DNS Servers the incoming Win95 or WinNT Connection
should use
# Two Servers can be remotely configured
# dns-addr 192.168.1.1
# dns-addr 192.168.1.2
# Specify which WINS Servers the incoming connection Win95 or WinNT
should use
# wins-addr 192.168.1.50
# wins-addr 192.168.1.51
# Specify the modem device the pppd should attempt to start a ppp
# connection too. You need to comment this out for a PPP Server setup.
/dev/ttyS3
# Specify the baud rate for the modem device.
# You should probably comment this out if you are using mgetty as your
# way of handling dialins. mgetty prepares everything so that ppppd does
# not need this parameter.
# 230400
###115200
# Use the executable or shell command specified to set up the serial
line.
# Here the default is to use the chat program to login to a remote
machine
# and start ppp. The -v flag will cause chat to log to
/var/adm/messages.
# Sensitive words in the /etc/ppp/chatscript file should be prefixed by
\q
# to stop chat writing these to the log file.
# This setting MUST be disabled for a PPP Server setup. If you want the
pppd
# to do both incoming and outgoing connection then the parameter has to
be
# specified on the commandline!
connect "/usr/sbin/chat -v -f /etc/chatscripts/chatscript_ipvos"
# Run the executable or shell command specified after pppd has
# terminated the link. This script could, for example, issue commands
# to the modem to cause it to hang up if hardware modem control signals
# were not available.
#disconnect "chat -- \d+++\d\c OK ath0 OK"
# async character map -- 32-bit hex; each bit is a character
# that needs to be escaped for pppd to receive it. 0x00000001
# represents '\x01', and 0x80000000 represents '\x1f'.
###asyncmap 0
# Require the peer to authenticate itself before allowing network
# packets to be sent or received.
# For a PPP Server with script based logins not using PAP or CHAP
# you need to disable this setting.
##auth
# Use hardware flow control (i.e. RTS/CTS) to control the flow of data
# on the serial port.
###crtscts
# Use software flow control (i.e. XON/XOFF) to control the flow of data
# on the serial port.
#xonxoff
# Don't use the modem control lines.
#local
# Specifies that pppd should use a UUCP-style lock on the serial device
# to ensure exclusive access to the device.
###lock
# Use the modem control lines. On Ultrix, this option implies hardware
# flow control, as for the crtscts option. (This option is not fully
# implemented.)
###modem
# Set the MRU [Maximum Receive Unit] value to <n> for negotiation. pppd
# will ask the peer to send packets of no more than <n> bytes. The
# minimum MRU value is 128. The default MRU value is 1500. A value of
# 296 is recommended for slow links (40 bytes for TCP/IP header + 256
# bytes of data).
# mru 1500
# Set the interface netmask to <n>, a 32 bit netmask in "decimal dot"
# notation (e.g. 255.255.255.0).
netmask 255.255.255.0
# 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).
noipdefault
# 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 does without this option).
passive
idle 30
holdoff 300
# 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 old versions of pppd).
#silent
# Don't request or allow negotiation of any options for LCP and IPCP
# (use default values).
#-all
# Disable Address/Control compression negotiation (use default, i.e.
# address/control field disabled).
#-ac
# Disable asyncmap negotiation (use the default asyncmap, i.e. escape
# all control characters).
#-am
# Don't fork to become a background process (otherwise pppd will do so
# if a serial device is specified).
#-detach
# Disable IP address negotiation (with this option, the remote IP
# address must be specified with an option on the command line or in an
# options file).
#-ip
# Disable magic number negotiation. With this option, pppd cannot
# detect a looped-back line.
#-mn
# Disable MRU [Maximum Receive Unit] negotiation (use default, i.e.
# 1500).
#-mru
# Disable protocol field compression negotiation (use default, i.e.
# protocol field compression disabled).
#-pc
# Require the peer to authenticate itself using PAP.
#+pap
# Don't agree to authenticate using PAP.
#-pap
# Require the peer to authenticate itself using CHAP [Cryptographic
# Handshake Authentication Protocol] authentication.
#+chap
# Don't agree to authenticate using CHAP.
#-chap
# Disable negotiation of Van Jacobson style IP header compression (use
# default, i.e. no compression).
#-vj
# Increase debugging level (same as -d). 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)). (If
# pppd is compiled with extra debugging enabled, it will log messages
# using facility local2 instead of daemon).
###debug
# 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 would
# use the domain option to set the domain name to Quotron.COM.
#domain <d>
# Enable debugging code in the kernel-level PPP driver. The argument n
# is a number which is the sum of the following values: 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.
#kdebug 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.
#mtu <n>
# Set the name of the local system for authentication purposes to <n>.
#name <n>
# Set the user name to use for authenticating this machine with the peer
# using PAP to <u>.
user bharries
# Enforce the use of the hostname as the name of the local system for
# authentication purposes (overrides the name option).
#usehostname
# Set the assumed name of the remote system for authentication purposes
# to <n>.
#remotename <n>
# 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.
##proxyarp
# Use the system password database for authenticating the peer using
# PAP.
##login
# If this option is given, pppd will send an LCP echo-request frame to
# the peer every n seconds. Under Linux, the echo-request is sent when
# no packets have been received from the peer for 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-echo-interval 30
# 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-failure 4
# Set the LCP restart interval (retransmission timeout) to <n> seconds
# (default 3).
#lcp-restart <n>
# Set the maximum number of LCP terminate-request transmissions to <n>
# (default 3).
#lcp-max-terminate <n>
# Set the maximum number of LCP configure-request transmissions to <n>
# (default 10).
#lcp-max-configure <n>
# Set the maximum number of LCP configure-NAKs returned before starting
# to send configure-Rejects instead to <n> (default 10).
#lcp-max-failure <n>
# Set the IPCP restart interval (retransmission timeout) to <n>
# seconds (default 3).
#ipcp-restart <n>
# Set the maximum number of IPCP terminate-request transmissions to <n>
# (default 3).
#ipcp-max-terminate <n>
# Set the maximum number of IPCP configure-request transmissions to <n>
# (default 10).
#ipcp-max-configure <n>
# Set the maximum number of IPCP configure-NAKs returned before starting
# to send configure-Rejects instead to <n> (default 10).
#ipcp-max-failure <n>
# Hint for /etc/ppp/ip-up.d/anmelder that it shall advertise the
# new temporary IP address to my friends
ipparam is_vossnet
# Set the PAP restart interval (retransmission timeout) to <n> seconds
# (default 3).
#pap-restart <n>
# Set the maximum number of PAP authenticate-request transmissions to
# <n> (default 10).
#pap-max-authreq <n>
# Set the CHAP restart interval (retransmission timeout for
# challenges) to <n> seconds (default 3).
#chap-restart <n>
# Set the maximum number of CHAP challenge transmissions to <n>
# (default 10).
#chap-max-challenge
# If this option is given, pppd will rechallenge the peer every <n>
# seconds.
#chap-interval <n>
# 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-local
# 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-accept-remote
# Hint for negotiation: Give remote server
#
##:enterprise.vossnet.de
# 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.
# It is probably advisable to use defaultroute for outbound connections
# only. In mixed mode defaultroute should be specified on the
commandline.
defaultroute
# 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.
#escape 11,13,ff
--
Bernd Harries
b...@gmx.de http://www.freeyellow.com/members/bharries
be...@linux-m68k.org Tel. +49 421 809 7351 priv. | MSB First!
har...@stn-atlas.de +49 421 457 3966 offi. | Linux-m68k
bhar...@vossnet.de | Medusa T40
<>_<> _______ _____
.---|'"`|---. | |_| |_|_|_|_|_|_|_ (_____) .-----.
______`o"O-OO-OO-O"o'`-o---o-'`-oo-----oo-'`-o---o-'`-o---o-'___