Step by step guide

Download and install PuTTY.

Download and install PuTTY from the following location:

If this link is invalid, perform a web search for "PuTTY".

Create a cryptographic key.

Create a cryptographic key using PuTTYGen (puttygen.exe) as follows:

  1. On the PuTTY Key Generator dialog box, click Generate.

  2. Change the Key comment to include your machine name and Windows username.

  3. Do not enter a key passphrase.

  4. Save the private key file without a passphrase.

    For example, C:\Users\username\Documents\id_rsa.ppk.

  5. Move the public portion of the key to the Linux machine. This requires you to edit the ~/.ssh/authorized_keys file on the Linux machine as follows:

    1. Open an SSH session to one of your cluster nodes, cd into ~/.ssh, and open the authorized_keys file in your favorite editor (for example, vi or Emacs).

    2. Copy all the text from the box under Public key for pasting and paste it into ~/.ssh/authorized_keys. All of this text should be one line.

    3. If the authorized_keys file does not exist, create one. Alternatively, paste it into a text file and move that file to the Linux machine for editing.

Modify system environment variables.

  1. Open the Windows System Properties dialog box (from Control Panel, select System, then Advanced system settings).

  2. On the Advanced tab, select Environment Variables. The Environment Variables dialog box appears.

  3. In the Environment Variables dialog box, locate the Path variable in the System variables pane.

  4. Select the Path variable and then click the Edit button. The Edit System Variable dialog box appears.

  5. Add the PuTTY install directory to the Variable value field separated by ; (for example, C:\Program Files\putty) and then click OK.

  6. In the System variables pane, click the New button. The New System Variable dialog box appears.

  7. In the New System Variable dialog, create a new environment variable named KEYPATH with a value containing the full path to the private key file (for example, C:\Users\username\Documents\id_rsa.ppk).

  8. Click OK.

  9. Reboot the computer for environment changes to take effect.

Fix a know bug on "ssh_init: Network error: Cannot assign requested address"

  1. Launch putty.exe
  2. On the PuTTY configuration box, select Default Settings.
  3. Verify Port is set to 22 and click Save.
  4. Close.

Fix the issue of "the server's host key not cached"

In the Windows command line, do the following, for example,


The server's host key is not cached in the registry. You
have no guarantee that the server is the computer you
think it is.
The server's rsa2 key fingerprint is:
ssh-rsa 2048 2e:db:b6:22:f7:bd:48:f6:da:72:bf:59:d7:75:d7:4e
If you trust this host, enter "y" to add the key to
PuTTY's cache and carry on connecting.
If you want to carry on connecting just once, without
adding the key to the cache, enter "n".
If you do not trust this host, press Return to abandon the
Store key in cache? (y/n)

Just answer y, and then Ctrl+C the rest.

Test SSH key authentication

  1. Launch putty.exe
  2. Enter the remote server Host Name or IP address under Session.
  3. Navigate to Connection > SSH > Auth.
  4. Click Browse... under Authentication parameters / Private key file for authentication.
  5. Locate the id_rsa.ppk private key and click Open.
  6. Finally, click Open again to log into the remote server with key pair authentication.

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