System Administration Guide

TroubleshootingTerminal and Modem Problems

If users are unable to log in over serial port lines after you have added a terminal or modem and set up the proper services, consider the following possible causes of failure.

  1. Begin by checking with the user.

    Malfunctions in terminals and modem use are typically reported by a user who has failed to log in or dial in. For this reason, it is best to begin troubleshooting by checking for a problem on the desktop.

    Some common reasons for login failure include:

    • Login ID or password is incorrect.

    • Terminal is waiting for X-ON flow control key (Control-q).

    • Serial cable is loose or unplugged.

    • Terminal configuration is incorrect.

    • Terminal is shut off or otherwise has no power.

  2. Check the terminal.

    Continue to troubleshoot by checking the configuration of the terminal or modem. Determine the proper ttylabel for communicating with the terminal or modem. Verify that the terminal or modem settings match those of the ttylabel.

  3. Check the terminal server.

    If the terminal checks out, continue to search for the source of the problem on the terminal or modem server. Use the pmadm command to verify that a port monitor has been configured to service the terminal or modem and that it has the correct ttylabel associated with it.


    $ pmadm -l -t ttymon
    

    Examine /etc/ttydefs and double check the label definition against the terminal configuration. Use sacadm to check the port monitor's status. Use pmadm to check the service associated with the port the terminal uses.

  4. Check the serial connection.

    If the Service Access Controller is starting the TTY port monitor and pmadm reports that the service for the terminal's port is enabled, and if the terminal's configuration matches the port monitor's, then continue to search for the problem by checking the serial connection. A serial connection comprises serial ports, cables, and terminals. Test each of these parts by using it with two other parts that are known to be reliable.

    Test all of the following:

    • Serial ports

    • Modems

    • Cables

    • Connectors

  5. Do not use Admintool or Solstice AdminSuite Serial Port Manager to modify serial port settings if the serial port is being used as a console. The correct procedure for changing console settings is by modifying the following line in the /etc/inittab file:


    co:234:respawn:/usr/lib/saf/ttymon -g -h -p "`uname -n` console
    login: " -T terminal_type -d /dev/console -l console -m
    ldterm,ttcompat