How to use the command 'tailscale ssh' (with examples)

Tailscale is a VPN service that creates a secure network of your devices, making them easier to interact with. The command tailscale ssh specifically allows for secure shell access to a machine on your Tailscale network. This command facilitates secure and streamlined SSH connections between devices, making it an invaluable tool for developers, system administrators, and IT professionals who need to manage multiple machines remotely. Below, we explore the practical use cases of this command with examples.

Use case 1: Advertise/Disable SSH on the host

Code:

sudo tailscale up --ssh=true

Motivation:

Enabling SSH on a host using Tailscale is crucial for those who wish to remotely manage their machine over a private network without exposing it to the public internet. By advertising SSH capability via Tailscale, users can ensure that they have secure and reliable access from anywhere within their network.

Explanation:

• sudo: This command is used to run programs with the security privileges of another user, by default the superuser. Here, it grants necessary permissions to modify the Tailscale settings on the machine.
• tailscale up: This command brings up the Tailscale interface, connecting the machine to the Tailscale network.
• --ssh=true: This flag explicitly enables SSH access through Tailscale. By setting this to true, it advertises that this machine can be accessed via SSH.

Example Output:

Starting Tailscale SSH on <machine_name>...
Machine is now accessible over Tailscale network with SSH.

Code:

sudo tailscale up --ssh=false

Motivation:

There might be situations where a user needs to disable SSH on a host for security reasons. Disabling SSH access can help prevent unauthorized access to the machine, especially if remote management is no longer required or if the machine is being decommissioned.

Explanation:

• sudo: As before, it runs the command with elevated privileges.
• tailscale up: Activates the Tailscale interface to ensure it’s ready to make network configurations.
• --ssh=false: This flag disables SSH access via Tailscale, ensuring that no incoming SSH connections are allowed.

Example Output:

Stopping Tailscale SSH on <machine_name>...
SSH access disabled for this machine over the Tailscale network.

Use case 2: SSH to a specific host which has Tailscale-SSH enabled

Code:

tailscale ssh username@host

Motivation:

After enabling SSH access on a machine within a Tailscale network, a user may want to connect to it remotely. This use case is highly relevant for developers or IT staff who need to perform maintenance, install software updates, or troubleshoot issues from a remote location. The tailscale ssh command simplifies the connection process, removing the need for complex VPN setups or exposing the machine to external threats.

Explanation:

• tailscale ssh: This part of the command initiates the SSH process via the Tailscale network, ensuring a secure and private connection.
• username@host: Here, username specifies the user account to log in with, while host identifies the machine you want to connect to. The host can be defined using a Tailscale IP address or a machine name.

Example Output:

Connecting to <host> as <username>...
Successfully authenticated. Welcome to <host>!
<username>@<host>:~$

Conclusion:

The command tailscale ssh serves as a robust solution for secure remote access within a Tailscale network. By allowing users to enable or disable SSH on their hosts and connect seamlessly with specific machines, it bridges the gap between convenience and security. This functionality is an asset for modern IT environments where remote connectivity and management are key. Users can confidently leverage these capabilities to maintain their networked machines efficiently and securely.