Linmodem Post Install Problems

A compilation of problems and solutions

Offered by Jacques Goldberg
Department of Physics, Technion, Haifa, Israel

Check here for updates - http://phep2.technion.ac.il/goldberg/post-install.html

    For the impatient:

    1. login as root or become su.
    2. execute wvdialconf
    3. edit /etc/wvdial.conf. Uncomment lines made idle by ; . Replace username, password and phone number by those supplied by your ISP (Internet Service Provider). Add the line Stupid Mode = yes
    4. open an additional window as root or su
    5. in the second window enter tail -f /var/log/messages
    6. return to first window and start wvdial
    7. watch the second window. If you see two IP addresses at the bottom (such as 111.222.33.444), you do not need me any more. Begin to work, in a new window. You can clear the messages with CTRL-C and you do not need it in future, nor the wvdialconf steps.
    8. alternately, after starting wvdial you can know if your session is ready with /sbin/ifconfig which if OK will show a pppd entry.
    9. if your reached this place, it is time to start an application (telnet, ftp, Web browser) and enjoy your modem.
    10. to stop the session and hang up the phone line, as su say killall pppd

    Troubleshooting:

    1. tail command does not work (messages file not found): you have it elsewhere or with some other name. Try find /usr -name messages and if not found go read /etc/syslog.conf to find the full path of the general log file. Newcomers: do not edit /etc/syslog.conf unless you know exactly what you are doing (requires restarting syslogd).
    2. have you studied Linmodem Resources ?
    3. wvdial or wvdialconf not found. Download e.g. from there and, as su, rpm -i the rpm file just downloaded. Return to step vwdialconf.
    4. NO DIALTONE message: please check your IRQ's, wrong, or conflicting. Use setserial -agv /dev/modem and cat /proc/interrupts, the latter should not show the IRQ reported by the former.
    5. Still NO DIALTONE: edit /etc/wvdial.conf. By default it shows place holders or text for 3 Init strings (you can add more up to 7). Try to add ATH1 as last command in last non empty string. Return to step vwdial.
    6. Still NO DIALTONE: add AT+GCI=xx in the Init string, where xx is your HEXADECIMAL country code found here. Your modem may be trying to listen to the wrong frequency.
    7. Still NO DIALTONE: find a cable known to work with an other modem and your phone line outlet, and try again (your cable may fail to match the phone company wiring - especially in Switzerland for example if the modem comes from elsewhere. Check that you have the right adaptor).
    8. wvdial sends ATZ, modem does not reply OK: installation failed. Reexamine all installation logs.
    9. wvdial waits for carrier, number is dialed, nothing else appears on the wvdial screen: wait for NO DIALTONE, NO ANSWER, BUSY, ...
    10. have really waited? Hit CTRL-C to kill wvdial and verify your phone connection and the number to be dialed. Do not forget prefixes such as 9 to get an external phone line from your exchange, and the like.
    11. modem has connected but ppp does not start. Look at the ppp log for the reason. Have you forgotten to add Stupid Mode = yes in your wvdial.conf?
    12. failed to authenticate? verify that there is no matching entry in /etc/ppp/chap-secrets. If you see your username and password in that file, comment the line with a leading # and retry. Warning: wvdial version 1.40 creates the line again, so use a more recent version. Note: some ISP servers use a copyrighted encryption algorithm for chap authentication, not supported by Linux pppd (at this time, at least).
    13. LCP / connection timed out: same as previous item. For more details on both, thoroughly study what does ISP want and learn about SPAP/CHAP/PAP to understand why it is so important not to have a valid entry in file chap-secrets, in order to avoid chap/spap encrypting problems.
    14. nothing helped: start minicom, set up the /dev/modem port to some reasonable baud rate, and 8N1 parity/lenth/stop bits. Try to dial the number with ATDT. If the other side answers, and nothing appears on you screen, try to hist ENTER a few times: some ISP's wait for it before prompting for the username. But some ISP's sleep until YOU start pppd (this is why you should remember Stupid Mode = yes )
    15. command AT&V will display all your modem settings. Report to us with this listing if nothing works, such as even does not dial.
    16. +++ resets the modem to command mode.
    17. (CTRL-A) Z X (not CTRL-A CTRL-Z etc...) make minicom exit
    18. CTRL-C will always kill minicom, even if seems stuck.
    19. see this link for a very comprehensive listing of modem commands (not all exist in all modems).


Help others too: report problems and solutions!

When asking for help, specify distribution, kernel, modem, driver, driver release, and include the wvdial log, and the ppp log found in /var/log/messages (cut away messages before and after the failing session)


Author:Jacques Goldberg
Created: 8 May 2001
Last update: 8 May 2001