SSH connection

Connecting via SSH

This simplest way to connect to the NYU remote server is via SSH. You need to be on the NYU network or connected via VPN. Then use the following settings:

Host: any of ecs03.poly.edu through ecs06.poly.edu
- Note: Previous versions of the class used ecs02.poly.edu. This server has not been upgraded with the latest Vitis / Vivado tools. Do not use this.
Username: your NetID
Port: 22

You can connect using any SSH client. Below are the recommended options depending on your operating system.

Windows: MobaXterm

MobaXterm is an excellent GUI SSH client for Windows.

Create a new SSH session using the settings above.
Log in with your NetID and password.
You will get:
- A terminal connected to the remote machine
- A remote file explorer panel on the left

You can drag and drop files between your local machine and the remote server. This is the easiest and most reliable method for Windows users, especially because Windows PowerShell’s scp does not work with the NYU EDA servers due to server‑side banner output.

macOS Terminal or Windows PowerShell

You can always log in from a terminal using:

ssh <netid>@ecs03.poly.edu

You may choose any of ecs03 through ecs06.

macOS users

macOS includes a robust OpenSSH implementation, so you can also use scp to copy files:

scp <netid>@ecs03.poly.edu:/home/<netid>/submission.py .

This downloads submission.py into your current local directory.

Windows users

The command scp will not work in Windows PowerShell because the NYU servers print a banner message that breaks PowerShell’s scp. Windows users should use MobaXterm or VS Code Remote‑SSH instead.

VS Code Remote‑SSH (macOS, Windows, Linux)

If you use VS Code, the Remote – SSH extension provides a full development environment on the remote machine.

Setup

Install the Remote – SSH extension in VS Code.
Open the Remote Explorer panel (icon on the left sidebar).
Under SSH Targets, click the + to add a new host.
Enter:
```
ssh <netid>@ecs03.poly.edu
```
Choose your user SSH config file when prompted
- Windows: C:\Users\<username>\.ssh\config
- macOS/Linux: ~/.ssh/config
Connect to the host. Wait for the status bar at the bottom left to turn green and read SSH: ecs03.poly.edu — until it does, you are still browsing your own machine.
File → Open Folder, and choose the repository directory, normally /home/<netid>/hwdesign.

Open the repository folder, not your home directory. VS Code keys a great deal off the folder you open. The Python extension looks for .venv relative to it, so opening your home directory means the environment you built in Using Python is never found, and every import waveflow is marked as an error even though the code runs fine. Opening your home directory also makes VS Code watch and search everything beneath it — including the several-hundred-megabyte ~/.vscode-server tree and the EDA tool directories — which makes the window noticeably sluggish, since home directories on these servers are network-mounted.

Course developers

If you are following the developer setup, you may want both the waveflow and hwdesign folders open at once. You do not need two VS Code windows, and you should not open your home directory to get both. Instead, use a multi-root workspace:

Open ~/hwdesign as above.
File → Add Folder to Workspace… and choose ~/waveflow.
File → Save Workspace As… and save it — for example as ~/hwdesign.code-workspace.

Both repositories now appear as top-level folders in a single Explorer, with search, Ctrl+P, and Source Control spanning the pair. Each folder keeps its own settings, and the editable install means an edit in waveflow takes effect in hwdesign immediately. Reopen the pair later from File → Open Workspace from File…, or from the Recent list.

This is only useful with the editable install described on that page. Students install waveflow as a package and never clone it, so a single ~/hwdesign folder is all they need.

What you get

A full VS Code environment running on the remote machine
A remote terminal
A remote file explorer
The ability to download or upload files via right‑click or drag‑and‑drop
The ability to edit files directly on the remote server with IntelliSense, syntax highlighting, etc.

This is the best option for macOS users and an excellent alternative for Windows users who prefer VS Code over MobaXterm.

If SSH warns that the host key has changed

When connecting you may be stopped by a warning like this, and the connection refused:

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!      @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
...
Offending ECDSA key in C:\Users\<username>/.ssh/known_hosts:6
Host key verification failed.

Your SSH client remembers an identifying key for every server you have connected to, and refuses to continue when the key it is offered does not match the one it recorded. The EDA servers were reinstalled during the recent tools upgrade, and a reinstalled machine generates new keys — so if you connected to these servers in a previous semester, you will see this.

Remove the stored key and reconnect:

ssh-keygen -R ecs03.poly.edu

Substitute whichever host you are connecting to. The command rewrites known_hosts and leaves a backup in known_hosts.old; it works on Windows, macOS, and Linux. Reconnect and answer yes when asked to accept the new key.

Prefer this to editing known_hosts by hand — a single host can occupy several lines, and deleting the wrong one is easy.

If VS Code Remote-SSH fails to connect with only a generic “could not establish connection” message, try connecting from a terminal first. VS Code hits the same host key check but reports it far less clearly.

This warning also has a genuine security meaning, and a routine server rebuild looks exactly like an attempted interception. Clearing the key is the right move here because we know these servers were reinstalled. On a machine you have no such explanation for, do not clear the key — contact whoever administers it.

Go to GUI connection with Fast-X