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VMware Serial Port Named Pipes

Just a quick one today.  VMware Workstation has the ability to attach serial ports to virtual machines and guest operating systems such as Vyatta use the /dev/ttyS0 serial port as a console port, allowing you to simulate administering the system “headless”.  One situation you may want to use this in is when you’re trying to copy screen text output for a blog :P.

Configuring VMware Virtual Machine

Follow these steps to add a serial port to your VMWare Workstation virtual machine:

  1. Attach the serial port to your VM.  Open your VM settings dialog and click Add
  2. Select Serial Port and click Next
  3. Select Output to named pipe and click Next
  4. Now you need to specify configuration for the named pipe.  Make sure you select “This end is the server” and “The other end in an application” otherwise you won’t get any output from your console.  Click Finish.

NOTE: The named pipe is created and deleted each time you power on, and power off your VM.

Configuring PuTTY Connection

When you launch PuTTY, you need to select Serial connection type, and then enter in the pipe name into the Serial Line text box:

Once you connect, you’ll be able to configure your VM (be it Vyatta, or some other flavour) all via the VM’s serial interface:

So there you have it.  Just a quick one today, but useful none the less.


  1. Iceman says:

    Thank you. This is exactly what I was looking for. This really helped me setup Olive on my system.

  2. Vitt Last says:

    By the way, it is possible to connect named pipe remotely via network.
    Just use \\%remote_server%\pipe\com_1 notation.

  3. Bob says:

    Many tks. I have look for this long time.

  4. seeker says:

    adam, I was trying to connect putty to esxi application and just exactly followed your instructions and got the “unable to open connection to \\.\pipe\vmwaredebug unable to open serial port”. any thoughts?

  5. Hari says:

    In vmware workstation I have 2 Vms. 1 Windows VM with Putty Client and other is Cisco Nexus Titanium VM.

    when i connect my Putty client to Titanium Vm over serial port I get following error:
    unable to open connection to \\.\pipe\com_1 unable to open serial port.

    On Windows VM i have added serial port.

    Please help

  6. Bryan says:

    bump on this… be sure you open putty as admin.

  7. Juani says:

    Why does my PuTTy shell stays pitch black? The log say is opening the pipe connection but it is like it waits forever an answer for the vitual target. Im using VMware, host is XP and target is Win 2003 server.

    Any help?

  8. Baris says:

    I have the same problem like “Hari”. Please help

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