Windows SSH

# Windows SSH with X Forwarding

This guide explains how to connect to the GRIT HPC system from Windows using SSH with X11 forwarding so graphical applications can display on your local machine.

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## 1. Install an X Server (Xming)

Install **Xming** using `winget`.

Open **Command Prompt** or **PowerShell** and run:

winget install Xming

After installation, start Xming from the Start Menu.

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2. Configure the DISPLAY Variable

Set the DISPLAY environment variable so remote X11 applications know where to send their output.

Run:

setx DISPLAY localhost:0

Close and reopen your terminal after running this command so the environment variable takes effect.

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3. Set Up SSH Key Authentication (Recommended)

Using SSH keys avoids typing your password every time and is more secure.

Generate an SSH Key

Open PowerShell and run:

ssh-keygen -t ed25519

Press Enter to accept the default file location:

C:\Users\<username>\.ssh\id_ed25519

You may optionally set a passphrase.

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Copy the Key to the HPC System

If ssh-copy-id is available:

ssh-copy-id [netid]@hpc.grit.ucsb.edu

If it is not available on Windows, run:

type $env:USERPROFILE\.ssh\id_ed25519.pub | ssh [netid]@hpc.grit.ucsb.edu "mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys"

Ensure the permissions on the HPC system are correct:

chmod 700 ~/.ssh
chmod 600 ~/.ssh/authorized_keys

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4. Connect to the HPC System

Connect with X11 forwarding enabled:

ssh -Y [netid]@hpc.grit.ucsb.edu

The -Y flag enables trusted X11 forwarding, allowing graphical applications to display on your Windows desktop.

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5. Test X Forwarding

After connecting, test with a simple X application:

xclock