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System Administration Guide: Advanced Administration
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Troubleshooting Terminal 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:

  • Check 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, 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

  • 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 the ttylabel settings.

  • 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. For example:

    $ pmadm -l -t ttymon

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

  • Check the serial connection.

    If the Service Access Controller is starting the TTY port monitor and the following is true:

    • The pmadm command reports that the service for the terminal's port is enabled.

    • The terminal's configuration matches the port monitor's configuration.

    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 one part with two other parts that are known to be reliable.

    Test all of the following:

    • Serial ports

    • Modems

    • Cables

    • Connectors

  • Do not use the Serial Ports tool to modify serial port settings if the serial port is being used as a console. Starting with the Solaris 10 release, invocations of ttymon for the console are managed by SMF. For step-by-step instructions on how to change the console terminal type, see How to Set the ttymon Console Terminal Type.

For more information on ttymon and SMF, see What's New in Managing Terminals and Modems?.

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  Published under the terms fo the Public Documentation License Version 1.01. Design by Interspire