The Essential Guide to Configuring SSH on Your Linux Server（linux服务器ssh配置）

The Secure Shell (SSH) protocol is widely used as a secure connection method between servers and clients in Linux systems. With SSH, you can easily set up encrypted tunnels to various remote systems, allowing you to manage and control them securely from anywhere. SSH is the essential tool for sysadmins to access the server remotely.

In this guide, we’ll go through the process of configuring SSH on your Linux server. We’ll begin by installing and setting up the SSH server, then look at how to access and manage it remotely.

First, let’s install the SSH daemon on your Linux server. If you’re using a Debian-based distribution, such as Ubuntu, you can use the following command to install it:

sudo apt-get install ssh

Before we move on, let’s make sure the SSH server is running. You can use the following command to check the status of the SSH server:

sudo service sshd status

If the SSH server is running, you should see a message indicating that it is active. If it isn’t, you can start it with the following command:

sudo service sshd start

We can now proceed to the next step which is configuring the SSH server. SSH uses a configuration file located in the `/etc/ssh` directory on your Linux server. This file contains all the settings for the SSH server, including port numbers, encryption methods, and user access policies. We’ll need to modify some of these settings before we can use SSH to access our server.

In the configuration file, look for the following settings:

* `PermitRootLogin` – Setting this value to `yes` allows you to log in as root on your server. This should be set to `no` unless absolutely necessary.

* `Port` – This is the port number the SSH server will use to listen for incoming connections. You can securely change this to any port between 1024 and 65535.

* `PasswordAuthentication` – This specifies whether the server will allow users to log in with a password or public key. It’s recommended to set this to `yes` and use public keys to log in instead.

Once you’ve edited all the necessary settings, save the configuration file and restart the SSH server. To restart the server, use the following command:

sudo service sshd restart

Now that our SSH server is configured and running, we can use it to access our server. To do this, we’ll need an SSH client. On Linux systems, the default SSH client is OpenSSH. You can use it to access your server using the following command:

ssh username@ipaddress

Here, `username` is your username on the server, and `ipaddress` is the IP address of your Linux server. You’ll be prompted to enter your password or passphrase, depending on how you’ve configured the server.

Now you’re connected and can start managing your server through SSH. You can use SSH to transfer files, configure services, and create remote backups.

We hope this guide has given you a better understanding of how to configure and use SSH on your Linux server. With it, you can securely access your server from any computer and increase your system’s security.