SDN-based Firewall with Ryu Controller

Description

This project demonstrates a basic SDN-based firewall implemented using the Ryu controller and Mininet. The firewall blocks traffic based on specific IP addresses, ports, and protocols (such as ICMP). It also logs dropped packets for auditing purposes.

Features

• ICMP (Ping) blocking: Blocks all ICMP traffic between hosts.
• Port-based filtering: Blocks specific TCP/UDP ports (e.g., SSH, HTTP).
• IP-based filtering: Blocks traffic from/to specific IP addresses.
• Traffic logging: Logs blocked packets for audit purposes.

Network Topology

The network consists of:

• 2 hosts (h1, h2)
• 1 OpenFlow switch (s1)
• Ryu controller managing the firewall rules.

Requirements

• Mininet
• Ryu controller

Setup Instructions

1.Clone this repository:

git clone https://github.com/ebongemma007/SDN-Firewall

2.Install Ryu:

sudo apt update
sudo apt install python3-ryu

3. Run the Ryu Firewall Application: Start the Ryu controller and run the firewall application

   ryu-manager firewall.py

5. Start Mininet with Custom Topology: Use the provided topology script to launch Mininet

   sudo python3 sdn_topology.py

7. Test the Network: Ping hosts to verify ICMP blocking

   mininet> h1 ping h2

You can also test port-based filtering using tools like netcat or attempt an SSH connection

mininet> h1 nc -l 80
mininet> h2 nc h1 80

Advanced Features:

Blocking Ports: Modify the firewall.py file to add or remove ports from the self.blocked_ports list. Blocking IPs: Add or remove IP addresses from the self.blocked_ips list in the firewall.py file.

Testing: Use Mininet's CLI to test the network. Run pingall to test ICMP blocking, or initiate TCP/UDP connections to test port-based filtering

Logs: Blocked packets are logged in the terminal for auditing purposes.

Contributing: Feel free to fork this repository and submit pull requests for enhancements or bug fixes.

License: This project is licensed under the MIT License. See the LICENSE file for details.