Configuring the Serial Line Internet Protocol (SLIP)

Troubleshooting dedicated manual SLIP links

To troubleshoot a dedicated manual SLIP link:

  1. Verify the soundness of the serial line connections. For SLIP to run over a dedicated serial line, the line itself and its connections at each end must be sound.

  2. Verify that the local and remote systems on the connection are set to use the same data transfer speed. For the local SCO OpenServer system, check the value of the baud_rate parameter for this SLIP link. For the remote system, check the data transfer speed setting in its configuration for this link.

  3. Test the serial line as follows if the line connections appear sound but the problem still appears to be in the line.

    NOTE: For this procedure, you must have access to the remote system, and the remote system must be running the UNIX operating system.

    Log into both machines as root.

    Disable SLIP for this serial line at both machines by killing the associated slattach process.

    Enable getty at the remote machine by executing the following command there:

    enable tty_number

    At the local machine, edit the file /usr/lib/uucp/Devices to be sure that the tty port for the serial line being used is configured for direct access and both systems specify the same speed. For example:
       Direct tty1a - 9600 direct

    Enter the following command on the source machine: cu -l tty dir, where tty is the name of the tty line you use.

    Your serial line is sound if the screen displays connected and the login prompt appears. Type ~. at the beginning of a line to exit the cu program.

    If there is no response, the problem probably lies with the cable. Check the cable's connections or try another cable. If an error message appears, see ``Connecting to other computers with UUCP''.

  4. Retry the slattach command with the +v flag in addition to your other parameters. This turns on verbose mode, allowing you to see the ongoing progress of slattach at the command line and identify potential problems.

  5. If you have still not located the source of the problem, see ``Using ping to troubleshoot SLIP link problems''.

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© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003