Login

Published

December 16, 2025

Prerequisites

You must be comfortable with Bash and basic HPC concepts. See: Unix Shell and HPC Introduction.

SSH Login Setup (Linux and macOS, recommended)

Here we will set-up passwordless SSH access to ADA.

ADA endpoints (for example ada.labs.vu.nl, inter01.labs.vu.nl) are only reachable on campus or via the VU VPN. Therefore we will use the public stepstone server ssh.data.vu.nl as a jump host (ProxyJump), so you could connect from anywhere.

End state

After setup you should be able to run:

ssh ada-login → ada.labs.vu.nl
ssh inter01 → inter01.labs.vu.nl

No passwords; the stepstone is used automatically.

Step 1 — Create an SSH key

On your local linux machine, generate a modern key and load it into your agent:

ssh-keygen -t ed25519 -C "<your VU email>" -f ~/.ssh/ada_ed25519
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/ada_ed25519

Step 2 — Configure SSH

Create or edit ~/.ssh/config and add:

Host stepstone-vu
    HostName ssh.data.vu.nl
    User <VUNETID>
    IdentityFile ~/.ssh/ada_ed25519
    ServerAliveInterval 120

Host ada-login
    HostName ada.labs.vu.nl
    User <VUNETID>
    ProxyJump stepstone-vu
    IdentityFile ~/.ssh/ada_ed25519
    IdentitiesOnly yes
    ServerAliveInterval 120

# Interactive nodes (pattern covers inter01–inter04)
Host inter0?
    HostName %h.labs.vu.nl
    User <VUNETID>
    ProxyJump stepstone-vu
    IdentityFile ~/.ssh/ada_ed25519
    IdentitiesOnly yes
    ServerAliveInterval 120

# Optional direct paths when on campus/VPN (no ProxyJump)
Host ada-login-direct inter0?-direct
    HostName %n.labs.vu.nl
    User <VUNETID>
    IdentityFile ~/.ssh/ada_ed25519
    IdentitiesOnly yes

Step 3 — Install your key on ADA

First copy your public key to the stepstone:

ssh-copy-id stepstone-vu   # prompts for your VU password

Then copy your public key to ADA:

ssh-copy-id ada-login   # prompts for your ADA password once

Test connections:

ssh ada-login

You should be logged into ADA without being prompted for a password!

SSH Login with MobaXterm (Windows)

Here we provide the steps to connect to the cluster using MobaXterm.

Download and install MobaXTerm from mobatek.net.
Open MobaXTerm and click on Session
Enter the Basic SSH settings as follows:
1. Remote host: ada.labs.vu.nl
2. Tick “specify username”
3. Enter your username (VUnetID)
Go to “Network settings” and click SSH gateway (jump host)
Enter the following details and click OK
1. Gateway host: ssh.data.vu.nl
2. Enter your username (VUnetID)
Save the settings. When not connected automatically, you can click on User sessions, and double click “ada.labs.vu.nl (VUnetID)”
You will be asked for a password for “ssh.data.vu.nl”. This is your NORMAL VUNETID password, NOT the cluster password your received from ITVO.
If not connected automatically, connect to the server again. Now you will see a terminal window which asks for another password. Here you should enter the CLUSTER password that you received from ITVO. Note that you will not see the cursor moving when typing. This is normal. When you finished typing your password hit ENTER.
You will now see a terminal window, similar to this one. On connecting for the first time, you will be asked to change your CLUSTER password. Enter your CLUSTER password, then enter a new password (this can be identical to your VUNETID password).
Congratulations, you are now connected to the cluster!

Login node policy

Login nodes are only for light tasks: edit scripts, manage files, submit SLURM jobs. Do not run notebooks, VS Code Server, heavy compiles, or long‑running programs here.

Use interactive nodes (inter01–inter04) for heavier interactive work, or see Open OnDemand in the Quick Start.

Optional tools

VS Code Remote‑SSH works with this config. Target inter01 (not ada-login).
MobaXterm (Windows) and iTerm2 (macOS) are optional SSH clients.
Remote desktop (RDP) to interactive nodes is available when on campus/VPN.

Troubleshooting (short)

Ensure VPN/campus access for *.labs.vu.nl; stepstone is public.
List loaded keys: ssh-add -l; add your key if missing.
Increase verbosity: ssh -vvv ada-login.
If you mistyped passwords too often, wait 15 minutes and try again.
File permissions: chmod 700 ~/.ssh; chmod 600 ~/.ssh/authorized_keys (on ADA).

Still stuck? Email itvo.it@vu.nl with OS, client, network location, and the verbose output of ssh -vvv ada-login.