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Command-line

Command-line

The "ssh" command (SSH protocol) is the standard way to connect to LCC. SSH also includes support for the file transfer utilities scp and sftp. Wikipedia is a good source of information on SSH. SSH is available within Linux and from the terminal app in the Mac OS. If you are using Windows, you will need an SSH client that supports the SSH-2 protocol: e.g. Bitvise, OpenSSH, PuTTY, or SecureCRT. The following will go over how to initiate a session using the ssh command or the equivalent; from the Linux command line.

LCC

Access LCC Login nodes

ssh myusername@lcc.uky.edu

The above command will rotate connections across all available login nodes and route your connection to one of them. To connect to a specific login node, use its full domain name:

ssh myusername@lcclogin1.ccs.uky.edu

To connect with X11 support on DLX2 (usually required for applications with graphical user interfaces), use the "-X" or "-Y" switch:

ssh -X myusername@lcclogin1.ccs.uky.edu

Access LCC DTN node

ssh myusername@dtn.ccs.uky.edu

Linux and Mac OS X operating systems:

On Linux and Apple Mac OS X operating systems, the ~/.ssh/config file enables you to specify many SSH settings, including those that keep alive an SSH connection. To do this, follow these steps:

  1. Use your preferred text editor to open the ~/.ssh/config file on your local computer.
    If the .ssh directory or the config file does not exist, create them using the following command:

    mkdir ~/.ssh && touch ~/.ssh/config.

  2. Add the following lines to the config file. The Host value can be any name you want; it is simply a label for the other settings. The Hostname value is the remote host you want to access; replace example.com with your domain name.

    Host example Hostname example.com ServerAliveInterval 240 ServerAliveCountMax 2

    • With this configuration, the SSH client sends a packet to the server every 240 seconds (4 minutes) to keep the connection alive.

  3. Save the changes to the config file.

  4. Also, make sure to run chmod 600 ~/.ssh/config to secure the the config file.

Info: If you experience problems when using SSH, such as dropped or unresponsive connections, you may need to adjust some settings in your SSH client to keep SSH session alive.

MCC

Access MCC Login nodes

ssh myusername@mcc.uky.edu

The above command will rotate connections across all available login nodes and route your connection to one of them. To connect to a specific login node, use its full domain name:

ssh myusername@mcclogin1.ccs.uky.edu (For login1 node) ssh myusername@mcclogin2.ccs.uky.edu (For login2 node)

Access the MCC DTN node

ssh myusername@mcc-dtn.ccs.uky.edu

Linux and Mac OS X operating systems:

On Linux and Apple Mac OS X operating systems, the ~/.ssh/config file enables you to specify many SSH settings, including those that keep alive an SSH connection. To do this, follow these steps:

  1. Use your preferred text editor to open the ~/.ssh/config file on your local computer.
    If the .ssh directory or the config file does not exist, create them using the following command:

    mkdir ~/.ssh && touch ~/.ssh/config..

  2. Add the following lines to the config file. The Host value can be any name you want; it is simply a label for the other settings. The Hostname value is the remote host you want to access; replace example.com with your domain name.

    Host example Hostname example.com ServerAliveInterval 240 ServerAliveCountMax 2

    • With this configuration, the SSH client sends a packet to the server every 240 seconds (4 minutes) to keep the connection alive.

  3. Save the changes to the config file.

  4. Also, make sure to run chmod 600 ~/.ssh/config to secure the the config file.

Info: If you experience problems when using SSH, such as dropped or unresponsive connections, you may need to adjust some settings in your SSH client to keep SSH session alive.

Center for Computational Sciences