How to setup ssh on Centos 9

Setting up SSH on CentOS 9 allows secure remote access to your server, providing encrypted communication for management, file transfer, and administration tasks. 

Step 1: Update Your System

Before configuring SSH, update your CentOS 9 system to ensure all packages are up to date and compatible with the latest OpenSSH server.

sudo dnf update -y

Step 2: Install OpenSSH Server

Install the OpenSSH server package to enable SSH functionality on your CentOS 9 system. This provides secure remote management capabilities.

sudo dnf install -y openssh-server

Step 3: Start and Enable SSH Service

After installation, start the SSH service and enable it to run automatically at system boot for continuous availability.

sudo systemctl start sshd
sudo systemctl enable sshd

Step 4: Configure SSH Settings

You can enhance security by editing the SSH configuration file. For example, change the default port or disable root login to prevent unauthorized access.

sudo nano /etc/ssh/sshd_config

Example modifications:

Port 2222
PermitRootLogin no
PasswordAuthentication yes

Step 5: Restart SSH Service

After making changes to the SSH configuration, restart the SSH service to apply the new settings and ensure secure remote access works correctly.

sudo systemctl restart sshd

Step 6: Allow SSH Through Firewall

If the firewall is enabled, allow the SSH port to ensure remote connections can reach your CentOS 9 server.

sudo firewall-cmd --permanent --add-service=ssh
sudo firewall-cmd --reload

Step 7: Test SSH Connection

Finally, verify that SSH is working correctly by connecting from another device using the server’s IP address and the username.

ssh username@server_ip