Texas Tech University

Connecting to HPCC Systems

Instructions for how to connect to the HPCC cluster login nodes depends on the operating system you are using as a client and whether you are attempting to sign in from within or from outside the TTU campus network. Instructions for each of these dependencies can be found below.

NOTE:

The campus ssh gateway is currently unavailable due to ongoing campus security investigations. Please use the campus GlobalProtect VPN for connections to the HPCC until further notice.

The HPCC doesn’t operate or control the ssh gateway or campus VPN, as these are operated by the campus networking group. For this reason we are unable to offer assistance with resolving problems connecting from off campus through these services. If one of these methods is not working for you for off-campus connections, we suggest that you try the other as described in the material below. If you encounter problems with accessing either or both of these services, please contact IT Help Central and/or review the material available in the Knowledge Base by searching at http://askit.ttu.edu on these topics.

Windows machines generally require installation of additional software as described below to enable ssh and optionally X11 access. MacOS and Linux computers usually already have ssh-compatible terminal programs built in, but may require additional software to enable X11 graphics applications. If connecting from off-campus, a VPN connection or jump connection (with -J) through the campus ssh gateway will be required to enable X11 forwarding; see below for details.

NOTE: Wherever you see the notation "<eraider>" on this page, substitute your own eRaider ID, without the brackets.

Table of Contents:

  1. Logging in to the HPCC Clusters using Windows
    1. Getting a Windows-compatible SSH client
    2. Connecting to HPCC Resources via SSH on Windows
  2. Logging in to the Linux Clusters using Linux/Mac
    1. Connecting from "On Campus" using Linux/Mac
    2. Connecting from "Off Campus" using Linux/Mac

Logging in to the HPCC Clusters using Windows

If you are connecting to the HPCC Linux clusters from the wired TTU network or the TTUnet wireless network, or if you are connected from off-campus through the TTU Global Protect VPN client, which currently requires use of Microsoft Multi-factor Authentication (MFA), then you are considered to be "on campus". Connections made from TTUHSC, the TTUguest wireless network or any other off campus site not in this list are treated as "off campus". For off-campus connections, follow the procedures outlined below and then navigate to the off-campus instructions for the SSH gateway at the end of this page.

Getting a Windows-comptible SSH client

For users to connect to the HPCC Linux cluster systems they need a Secure Shell (SSH) client. Windows provides an SSH client through its PowerShell window or Command Prompt windows but most Windows users prefer to use one of the following SSH Windows applications. Other available options for plain-text terminals include Termius, which is also available for macOS, Windows, Linux, iOS and Android.

  • Plain-text-only terminal applications:
    • Windows Subsystem for Linux (WSL) - Available on Windows 10 or above only
      • Windows Subsystem for Linux (WSL) is a lightweight Linux client available as an add-in to the Windows operating system. The current version is WSL2.
      • It is turned off by default. To enable it please follow these directions from Microsoft. Microsoft also has published complete directions on How To Install Linux with four options: using Windows Subsystem for Linux, using a local VM, using a cloud VM, or on bare metal, so if you are going to make use of Linux on a regular basis starting from a PC, you may wish to pursue one or more of these methods.
      • Once installed, you can continue connecting to our Linux clusters using the "Logging in to the Linux Clusters using Linux/Mac" section below.
    • PuTTY - Available for all version of Windows
      • PuTTY is a lightweight SSH client developed by Simon Tatham.
      • PuTTY can be downloaded (for free) from the PuTTY Website.
  • X11 graphics-enabled applications:
    • MobaXterm is an enhanced terminal application for Windows with X11 server, tabbed SSH client, network tools and more. If you are needing to display X applications from the HPCC system, MobaXterm makes it easier since it does not require other additional programs to provide X11 forwarding, but you do need to ensure that the "X11 forwarding" checkbox is selected when setting up your connection session.

Connecting to HPCC Resources via SSH on Windows

Once you have obtained and installed a suitable SSH client on Windows, please follow the instructions below to make a connection:

  • Windows Subsystem for Linux (WSL) - Available on Windows 10 or above only
    • Because this method will install a lightweight version of Linux on your system, you can continue connecting to our Linux clusters using the "Logging in to the Linux Clusters using Linux/Mac" section below, which includes sections on connecting from on campus and from off campus.
  • PuTTY - Available for all version of Windows
  • MobaXterm has an extensive help page showing how to connect, including how to set up port forwarding in a way similar to PuTTY for off-campus connections. In general, these are similar to the instructions below. As mentioned above, be sure the "X11 forwarding" checkbox is selected when setting up your connection session if you intend to use X11-enabled GUI appications such as MATLAB, Paraview, etc. See the documentation for this application for details.

Logging in to the Linux Clusters using Linux/Mac

If you are connecting to the Linux clusters from the wired TTU network or the TTUnet wireless network, or if you are connected from off-campus through the TTU Global Protect VPN client, which as of mid-2023 requires use of the campus MIcrosoft Multi-factor Authentication system, then you are considered to be "on campus". Connections made from TTUHSC, the TTUguest wireless network or any other off campus site not in this list are treated as "off campus". For off-campus connections, follow the procedures outlined below and then navigate to the off-campus instructions for the SSH gateway at the end of this page.

On Macs, the built-in Terminal application can be used for plain-text connections without installation of any additional applications, and XQuartz is the best option for X11 graphics-enabled usage. Linux systems generally include a terminal application and options to install X.org X11 support for graphics-enabled applications. When using X11, be sure to add the "-X" flag to the ssh commands given below to enable X11 forwarding.

Other available options for plain-text terminals include Termius, which is available for macOS, Windows, Linux, iOS and Android.

Connecting from "On Campus" using Linux/Mac

Open a new console/terminal and type in the following, substituting your own eRaider ID where "<eraider>" is shown:

#Connecting to RedRaider
ssh <eraider>@login.hpcc.ttu.edu

You will be prompted for your eraider password and once you have entered it you will be logged into the cluster where you can begin submitting jobs.

Connecting from "Off Campus" using Linux/Mac, WSL, or other terminal applications:

If you are connecting to the Linux clusters from the wired TTU network or the TTUnet wireless network, or if you are connected from off-campus through the TTU Global Protect VPN client, then you are considered to be "on campus".

Connections made from TTUHSC, the TTUguest wireless network or any other off campus site not in this list are treated as "off campus". All external traffic to the HPCC servers must first flow through the SSH gateway. You will first need to connect to the SSH gateway and then connect to login.hpcc.ttu.edu from there. To do this you will need to first open a new console/terminal and type in the following, substituting your own eRaider ID where "<eraider>" is shown:

#Connect to the TTU SSH Gateway
ssh <eraider>@ssh.ttu.edu

You will be prompted for your eraider password, type it in then press enter. Once you have successfully entered your eraider password, the system will respond back with:

You are now connected to the TTUnet SSH Gateway. 
Please specify the following information to continue
connecting via SSH to a device on the network.
This connection will automatically timeout in 24 hours
Hostname or IP Address of SSH instance:
#Enter: login.hpcc.ttu.edu

User account to connect with:
#Enter your eraider username

You will be prompted for your eraider password and once you have entered it you will be logged into the respective login node where you can begin submitting jobs.

If you wish to connect in just one command line through the ssh gateway, please follow the instructions below. This method is required for ssh sessions through the campus ssh gateway if you want to use X11 forwading. The format of this command depends on which version of SSL you are using.

With OpenSSH (used in Linux, Mac, and optionally installable in WSL), you can use the "-J" (jump) flag to do this as shown below, substituting your own eRaider ID where "<eraider>" is shown:

#Connecting to RedRaider off-site through TTU SSH gateway using OpenSSH
ssh -J <eraider>@ssh.ttu.edu <eraider>@login.hpcc.ttu.edu

If your setup is using other older versions of SSH, such as built into PuTTY or the current default WSL, connecting in one line from off-site requires the following set of flags, substituting your own eRaider ID where "<eraider>" is shown:

#Connecting to RedRaider off-site through TTU SSH gateway 
#other SSH versions
ssh -o ProxyCommand="ssh -W %h:%p <eraider>@ssh.ttu.edu" <eraider>@login.hpcc.ttu.edu

In each case, you will have to enter your eRaider password twice (once for the SSH gateway and once for the cluster login node).

GUI-based SSH applications such as MobaXterm and Termius, include options to allow port forwarding to be set up to use the TTU SSH gateway for off-campus connections. For instructions on how to configure such settings, please consult the help instructions in the web sites for these programs.

 

High Performance Computing Center