http://www.mandrakeuser.org/docs/connect/cppp3.html

MandrakeUser.Org - Your Mandrake-Linux Knowledge Base!

 
 

* DocIndex - Connectivity

Dial-up Networking (PPP) III

* Generating Error-Logs
* Modem doesn't react at all
* Modem does react, but doesn't dial
* Modem dials every second time only
* Modem does react and dial, but it drops the connection immediately
* Modem does react, dials but drops connection after 20 seconds
* Connection establishes, holds, but you can't get anywhere

Related Resources:

Linux PPP FAQ
PPP HOWTO, 22
Modem HOWTO, 15

Revision / Modified: July 31, 2001
Author: Tom Berger

 

* Generating Error-Logs

'pppd' logs messages in '/var/log/messages'. This is the first place to have a look at if something doesn't work (e.g. less /var/log/messages as 'root').
For debugging purposes it is advisable to let 'pppd' and 'chat' write their messages in a file of their own:

  1. Make a backup of '/etc/syslog.conf' (e.g. cp /etc/syslog.conf /etc/syslog.conf.orig)

  2. Add these lines to /etc/syslog.conf:

    local2.* /var/log/ppp daemon.* /var/log/ppp

  3. Run

    touch /var/log/ppp

  4. Start 'pppd' with the 'debug' option, like /usr/sbin/pppd debug call [name] This will log every message sent and received by 'pppd' to '/var/log/ppp'.

  5. If you've got everything up and running, you might want to revert these changes by copying back '/etc/syslog.conf.orig'.

* section index *

* Modem doesn't react at all

  • You've specified the wrong serial port. Check your settings in the 'peers' file.

  • Check your cable connections.

  • Check if the modem is actually supported by Linux.

* section index *

* Modem does react, but doesn't dial

Have a look at '/var/log/messages'. Most likely you will see this message:

Connect script failed

This may have various reasons:

  • Bad chat-script. Check filename of chat-script, check modem init-string, look for typos. Increase time-out or try the chat-script provided by the ppp.rpm ('/usr/doc/ppp-[version]/scripts/ppp-on-dialer').

  • Bad telephone line, flaky modem. Remove the appropriate ABORT options from your chat-script ("NO ANSWER", "NO DIALTONE") one by one. At some point pppd will not time out. This is where the error lies.

* section index *

* Modem dials every second time only

Your modem is set to 'Abort connection if DTR ? OFF' ('&D2'). Add &D1 to your modem's init-string in your 'chat' file. This will set the modem to 'Switch to command phase if DTR ? OFF'.
If this doesn't work, you've specified the wrong init-string in your chat-file.

* section index *

* Modem does react and dial, but it drops the connection immediately

  • Check telephone-number.

  • Try again. Maybe your ISP's server was just busy at that moment.

  • Check your scripts for typos!

  • Make sure you have no superfluous entries in '/etc/ppp/options'.

* section index *

* Modem does react, dials but drops connection after 20 seconds

'/var/log/messages' (or '/var/log/ppp') reads:

LCP: timeout sending Config-Requests

  • Check the 'options'-file. Add these options

    • asyncmap 0xa0000

    • novj

  • Check '/var/log/ppp' for entries like <auth pap> or <auth chap>. Do you use the right 'secrets' file? Enter your account name and passwords into both files and try again.
    If you see messages like "Unknown digest type" or "Unknown CHAP code", your provider uses non-standard authentication protocols. Demand an alternative login-procedure and if they fail to, get a new provider.

* section index *

* Connection establishes, holds, but you can't get anywhere

  • Being offline, run /sbin/route -n as root. There shouldn't be any entry starting with '0.0.0.0'. Such an entry means that there already is a default route on your system. In this case, run /sbin/route del default. Try to find out what sets this default route.
    The 'Linuxconf' version distributed with ML 7 seems to insist on setting a default route, if you configure a local network and a dial-up connection with it. Check the file '/etc/sysconfig/network' and remove any lines which start with GATEWAY or GATEWAYDEV.

  • Add one or more of these options to '/etc/ppp/options':
    defaultroute, noipdefault, noccp, nobsdcomp, novj, novjcomp, noaccomp, nopcomp.
    This varies from ISP to ISP, so try until you find a combination which works ;-).

If you still haven't got a connection, read the 'debugging' section of the 'PPP-HOWTO' in '/usr/share/doc/HOWTO' for more information or the PPP-FAQ.

* section index *

* Dial-up LAN


 
Legal: All texts on this site are covered by the GNU Free Documentation License. Standard disclaimers of warranty apply. Copyright LSTB (Tom Berger) and Mandrakesoft 1999-2002.