How to create Firewall rules for your Linux server

To create firewall rules for your Linux VPS, you will need to follow the steps below:

1. Log in to your server as the root user via SSH (Secure Shell) or through the console access method.
   
   
2. Check if a firewall is already installed on your server. If not, you will need to install one before proceeding.
   Popular firewall software for Linux servers includes UFW (Uncomplicated Firewall), iptables, and firewall.
   
   
3. Once you have installed a firewall, you can begin creating rules.
   Firewall rules specify which traffic should be allowed or blocked on your server based on IP addresses, ports, and protocols.
   
   
4. To create a new firewall rule, use the command-line interface to specify the source and destination IP addresses, ports, and protocols.
   
   Here's an example of how to create a rule to allow traffic on port 80 (HTTP):

For UFW:

      ufw allow 80/tcp



For iptables:

iptables -A INPUT -p tcp --dport 80 -j ACCEPT

For firewall:

firewall-cmd --add-service=http --permanent

firewall-cmd --reload

Once you have created your firewall rules, you should test them to make sure they are working correctly.

Try accessing your server from another computer or running a network scanner to verify that the rules are blocking or allowing traffic as intended.

Finally, you should regularly review and update your firewall rules as needed to ensure that your server is adequately protected, and that legitimate traffic is not blocked.

Note: configuring firewalls can be a complex task and may require expertise in network security.

If you are unsure how to create firewall rules for your server, it is recommended that you seek the assistance of a qualified system administrator or security expert.