Clearing a Terminal Server Port




How do you know that the port on the terminal server needs to be cleared?
  • A terminal server port will only allow one login at a time. If a telnet session already exists for a port, then an error message will be displayed that looks similar to this:
     
    
    % telnet digi.itlabs.umn.edu 2001 Trying 128.101.37.251... telnet: Unable to connect to remote host: Connection refused % ...or, a telnet window will quickly appear and then close before it can be read.
    How do you fix it or clear the line?
    Find the telnet port number for the device that has problems.
  • Go to the web page that lists the telnet port numbers with the correct device and the IP name of the terminal server.



    For example:
    R1 is port number 7 on the terminal server digi.itlabs.umn.edu
    S4 is port number 4 on the terminal server digi.itlabs.umn.edu


    2. Login to the digi terminal server as root.
  • Telnet to the terminal server with the default telnet port of 23. Login as root. It should look similar to this:

    Trying 128.101.37.251... Connected to digi.itlabs.umn.edu. Escape character is '^]'. Terminal Server for devices Hit RETURN 2 times after login TS Login: root TS passwd: #>

    3. Run the command "who"
  • The port number found in the first step will be the tty number on the terminal server. The "who" command will verify that the tty is in use. It might look similar to this:


    #> who tty username nsess connected_from connected_to 1 root 0 funnelcake direct_tty01 17 root 0 thorin local_shell #>


    4. Run the command "kill tty=tty number"
  • Any tty that is greater than 16 is a telnet to the terminal server using the default port of 23. The other tty of 1 is the only other connection. This is the tty that needs to be cleared. To kill the tty of 1, just run the command "kill tty=1" at the root prompt. It will look like this:


    #> kill tty=1
    5. Check to make sure the connection is gone by running another "who" command.


    #> who tty username nsess connected_from connected_to 17 root 0 thorin local_shell #>
    If the tty is not listed, it should be OK to try connecting to the device again.



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