Introduction: Welcoming and Informing the Audience
Bridging the gap between remote computers can be challenging when security is a concern. In today’s world, where telecommuting has become common, you can’t compromise when it comes to access to your server remotely. But how do you create a secure remote connection with your Debian Stretch server? The answer is simple: install SSH server. In this article, we’ll guide you on how to install SSH server on your Debian Stretch and how to make a secure connection from another computer or device.
If you’re familiar with Debian and Linux command lines, this task will be relatively easy for you. However, if you’re new to it, don’t worry; we’ll provide you with all the necessary commands and explanations.
By the end of this article, you’ll have a secure connection with your Debian Stretch server, and you’ll be able to access it remotely from another computer.
Let’s get started!
Section 1: What is SSH and Why is it Necessary?
Secure Shell (SSH) is a network protocol that allows secure communication over an unsecured network, such as the internet. Using SSH, you can create a secure connection between a client and a server. This connection is encrypted, making it difficult for anyone to eavesdrop on your communication.
SSH is an essential tool when working remotely with a server. It’s the standard protocol for remote access to Linux and Unix servers. With SSH, you can access your server’s command line remotely, transfer files securely, and execute commands from anywhere.
SSH uses public-key cryptography to authenticate the remote computer and allow you to connect securely. This means that only computers with the correct private key can log in to your server.
Now that you know what SSH is and how it works, let’s move on to setting it up on your Debian Stretch server.
Section 2: Installing SSH Server on Debian Stretch
The first step is to verify that your Debian Stretch server doesn’t have SSH server installed yet. To do this, open a terminal and enter the following command:
| ssh localhost |
If SSH server is installed, you’ll see a response like:
| The authenticity of host ‘localhost (::1)’ can’t be established. |
| ECDSA key fingerprint is SHA256:xxxxxxxxxxxxxxx. |
| Are you sure you want to continue connecting (yes/no)? |
If SSH server isn’t installed, you’ll see the following response:
| ssh: connect to host localhost port 22: Connection refused |
If SSH server isn’t installed, you need to install it. To do this, enter the following command:
| sudo apt-get install openssh-server |
This command will install the SSH server on your Debian Stretch server. Once the installation is complete, the SSH server will start automatically.
Section 3: Configuring SSH Server on Debian Stretch
Now that you’ve installed SSH server on your Debian Stretch server, you need to configure it. The configuration file for SSH server is located at /etc/ssh/sshd_config.
It’s recommended to make a backup of this file before making any changes. To do this, enter the following command:
| sudo cp /etc/ssh/sshd_config /etc/ssh/sshd_config_backup |
Now, you can edit the configuration file using your favorite text editor. We recommend using nano, which is a simple and easy-to-use text editor. To open the configuration file with nano, enter the following command:
| sudo nano /etc/ssh/sshd_config |
This will open the configuration file in nano. You’ll see a list of settings that you can modify. Here are some essential settings:
Port Number
The default port number for SSH is 22. However, it’s recommended to change the port number to a different number to make it harder for attackers to find your SSH server. To change the port number, locate the line that says “Port 22” and change it to your desired port number. For example:
| Port 11111 |
Save your changes by pressing Ctrl+X, then Y, then Enter.
Login Settings
You can set a few settings to control who can log in to your SSH server. For example, you can allow only specific users to log in, or you can disable password authentication and require public key authentication. Here are some settings:
| PermitRootLogin no |
| PubkeyAuthentication yes |
| PasswordAuthentication no |
| AllowUsers user1 user2 |
The first setting, “PermitRootLogin no,” disables root login. This is recommended for security reasons, as it’s safer not to log in as the root user. The second setting, “PubkeyAuthentication yes,” enables public key authentication. This means that users need to have a valid private key to log in. The third setting, “PasswordAuthentication no,” disables password authentication. This means that users can’t log in with a password; they need a private key. The fourth setting, “AllowUsers,” allows only specific users to log in.
Restart SSH Server
After you’ve made the necessary changes to the configuration file, you need to restart the SSH server for the changes to take effect. To do this, enter the following command:
| sudo systemctl restart sshd.service |
This will restart the SSH server and apply your changes.
Section 4: Connecting to SSH Server from another Computer
Once you’ve installed and configured SSH server on your Debian Stretch server, you can connect to it from another computer. To do this, you need an SSH client. There are many SSH clients available, such as PuTTY for Windows or OpenSSH for Linux and Mac.
Here’s how to connect to your SSH server using OpenSSH:
| ssh username@ip_address -p port_number |
Replace “username” with the username of the user you want to log in as, “ip_address” with the IP address of your Debian Stretch server, and “port_number” with the port number you’ve set in the configuration file. For example:
| ssh john@192.168.0.100 -p 11111 |
If you’ve configured public key authentication, you need to have a valid private key on the computer you’re connecting from. If you’ve disabled password authentication, you can’t log in with a password.
Section 5: Advantages and Disadvantages of Using SSH Server
Advantages
Here are some advantages of using SSH server:
| 1. Secure: SSH provides secure communication over an unsecured network, such as the internet. |
| 2. Versatile: SSH can be used for remote access to a server’s command line, file transfer, and tunneling. |
| 3. Encryption: SSH uses encryption to protect your communication from eavesdropping. |
| 4. Authentication: SSH uses public-key cryptography to authenticate the remote computer and allow a secure connection. |
Disadvantages
Here are some disadvantages of using SSH server:
| 1. Complexity: SSH can be complex, especially if you’re new to Linux command lines. |
| 2. Configuration: SSH requires configuration to work properly, which can be time-consuming and challenging. |
| 3. Ports: SSH uses a specific port number, which can be blocked by firewalls or routers. |
| 4. Security: If you don’t configure SSH properly, it can pose a security risk. |
Section 6: Frequently Asked Questions (FAQs)
1. What is SSH?
SSH (Secure Shell) is a network protocol that allows secure communication over an unsecured network, such as the internet.
2. Why is SSH necessary?
SSH is necessary when working remotely with a server because it provides secure access to the server’s command line, file transfer, and tunneling.
3. How do I install SSH server on Debian Stretch?
You can install SSH server on Debian Stretch by entering the following command: sudo apt-get install openssh-server.
4. How do I configure SSH server on Debian Stretch?
You can configure SSH server on Debian Stretch by editing the configuration file located at /etc/ssh/sshd_config.
5. What are some essential settings for SSH server configuration?
Some essential settings for SSH server configuration include changing the port number, disabling root login, enabling public key authentication, and disabling password authentication.
6. How do I connect to SSH server from another computer?
You can connect to SSH server from another computer using an SSH client, such as OpenSSH. Enter the following command: ssh username@ip_address -p port_number.
7. What are some advantages of using SSH server?
Some advantages of using SSH server include secure communication, versatility, encryption, and authentication.
8. What are some disadvantages of using SSH server?
Some disadvantages of using SSH server include complexity, configuration, port issues, and security risks.
9. How can I make SSH more secure?
You can make SSH more secure by changing the default port number, disabling root login, enabling public key authentication, and disabling password authentication. It’s also essential to keep your SSH server and client updated and to use strong passwords or public key authentication.
10. What is the difference between SSH and SSL?
SSH and SSL (Secure Sockets Layer) are both encryption protocols that provide secure communication. However, SSH is used for remote access to a server’s command line, while SSL is primarily used for secure communication between a client and a server, such as for web browsing.
11. What are some popular SSH clients?
Some popular SSH clients include OpenSSH for Linux and Mac, PuTTY for Windows, and WinSCP for Windows.
12. Can SSH be used on other operating systems besides Linux and Unix?
Yes, SSH can be used on other operating systems, such as Windows, by using an SSH client.
13. Is SSH free?
Yes, SSH is free and open-source software.
Section 7: Conclusion: Encouraging Readers to Take Action
Congratulations, you’ve successfully installed and configured SSH server on your Debian Stretch server! You can now access your server remotely from another computer securely. Remember to keep your SSH server and client updated and to use strong passwords or public key authentication.
If you’ve encountered any issues or have any questions, don’t hesitate to ask for help from a Linux expert or a community forum.
Thank you for reading this article, and we hope it has been helpful to you!
Closing Disclaimer
The information provided in this article is for educational and informational purposes only. We do not take any responsibility for any harm, loss, or damage caused by the use or misuse of this information. Use at your own risk.