Google Cloud IoT Core, SSH into Devices

Google Cloud IoT Core, while powerful for managing and securing IoT devices, does not provide direct access to device IP addresses or the ability to establish SSH connections to devices. The core purpose of IoT Core is to securely route telemetry data to the cloud, manage devices, and send commands back to them, but it does not manage network-level access (like IP addresses or SSH connections) for devices.

However, you can still implement an architecture that allows SSH access to your devices using other components of Google Cloud. Here’s how you can establish remote SSH access to IoT devices in a secure manner:

1. External IP and Networking

To SSH into your devices, the device itself must be reachable over the network, typically via an external IP address. If your devices are connected to a network that provides internet access, they could have either:

• Dynamic IPs: Assigned by the network (e.g., via DHCP), which can change over time.
• Static IPs: Manually assigned, which remain constant but are less common in consumer networks.

If your device has an external IP and is reachable over the internet, you can SSH directly into the device, provided it is configured to allow SSH and you have the necessary credentials.

However, Google Cloud IoT Core does not expose or manage these IP addresses. Instead, you need to rely on the device’s network or implement an additional service layer to obtain this information.

2. Using Cloud IoT Core with a VPN or Reverse SSH Tunnel

If your devices are located behind NAT or on private networks (common in B2B environments), direct SSH access might not be possible. You can address this in a few ways:

A. VPN (Virtual Private Network)

You could set up a VPN to create a secure, private network for your devices, making them accessible to your support team. With this approach:

1. Install a VPN client on the IoT devices.
2. Connect the devices to a VPN server hosted in your cloud or on-premises network (e.g., using OpenVPN or Google Cloud VPN).
3. Once connected, devices will have private IP addresses within the VPN, and your support team can SSH into them using these private IPs.

B. Reverse SSH Tunnel

If direct SSH access is not feasible due to NAT or firewall restrictions, you can use a reverse SSH tunnel to initiate the SSH connection from the device to a central server that you control. This technique allows you to access the device from the server even when the device is behind a restrictive network.

• Step 1: Set up a central server (e.g., a Google Cloud VM) with a static IP or DNS name.
• Step 2: Configure each IoT device to open an SSH connection to the central server and establish a tunnel.
• Step 3: Through the tunnel, you can SSH into the device from the central server.