SSH Access — Magus02 HPC

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📍 Magus02 Knowledge Base → Basics → SSH Access

SSH (Secure Shell) is the standard protocol for accessing Magus02. It provides encrypted command-line access to the cluster's login nodes.

General

SSH allows you to log into a remote computer over a network and execute commands as if you were physically present. On Magus02, SSH connects you to the login nodes — dedicated front-end machines from which you can compile code, manage files, and submit jobs to Slurm.

⚠️ Important: Access to Magus02 login nodes is restricted to the SNU campus network. If you are off-campus, you must first connect to the SNU VPN before SSH will work. See the External Access section below.

SSH Clients by Platform

Linux / macOS

OpenSSH is pre-installed. Open a terminal and run:

$ ssh [email protected]

On first connection, you will be asked to verify the host fingerprint — type yes to accept. Enter your password when prompted.

To enable X11 forwarding (for graphical applications):

$ ssh -X [email protected]
# If -X doesn't work, try -Y (trusted forwarding):
$ ssh -Y [email protected]

Windows

Since Windows 10 version 1709, SSH is built in. Open Command Prompt or PowerShell and run:

ssh [email protected]

Alternatively, use a dedicated SSH client:

Client	Notes	Download
PuTTY	Classic, lightweight, widely documented	putty.org
MobaXterm	Integrated SSH + X11 + SFTP file browser	mobaxterm.mobatek.net
Bitvise	Full-featured SSH + SFTP client	bitvise.com
Windows Subsystem for Linux (WSL)	Full Linux environment within Windows; use `ssh` natively	Built-in (enable via Windows Features)

SSH Key Authentication

For convenience and improved security, use SSH key pairs instead of passwords. Generate a key pair on your local machine:

$ ssh-keygen -t ed25519 -C "[email protected]"
# Accept the default location (~/.ssh/id_ed25519)
# Set a strong passphrase

# Copy your public key to Magus02:
$ ssh-copy-id [email protected]

After this, SSH logins no longer require typing your password each time.

External Access — VPN

🔒 VPN Required for Off-Campus Access

To access Magus02 from outside the SNU campus network, a VPN connection is mandatory. Without it, the SSH connection will time out. To obtain VPN credentials, submit a VPN Request Form to the HPC admin team or scan the QR code in your welcome email.

Once VPN is active, SSH works exactly as normal:

# 1. Connect to SNU VPN using the provided client
# 2. Then SSH as usual:
$ ssh [email protected]

Resetting Your Password

Step 1: Log in to Magus02 via SSH with your current password.
Step 2: Run the passwd command:

[user@magus02 ~]$ passwd
Changing password for user user.
Current password: ••••••••
New password: ••••••••
Retype new password: ••••••••
passwd: all authentication tokens updated successfully.

🔐 Password Policy: Minimum 8 characters; must include uppercase, lowercase, numbers, and special characters. Shared passwords are strictly prohibited.

References

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