[Paper Review] Implementing Software Defined Load Balancer and Firewall

Shreya Rajkumar|arXiv (Cornell University)|Nov 28, 2022

Software-Defined Networks and 5G4 citations

TL;DR

This paper proposes and implements a software-defined load balancer and firewall using the Floodlight SDN controller, enabling centralized, dynamic traffic management. By decoupling control from data planes, the system dynamically directs traffic and enforces security policies across network devices without manual configuration, demonstrating effective load distribution and access control in a test environment.

ABSTRACT

Software-defined networking (SDN) is an architecture that aims to make networks fast and flexible. SDN's goal is to improve network control by enabling service providers as well as enterprises to respond quickly to changing business needs. In SDN, the administrator can shape traffic from a centralized control console without having to modify any of the individual switches belonging to the network. The SDN controller which is centralized directs the switches to deliver network services wherever they are needed, irrespective of the specific connections between a server and devices. This methodology is a shift from traditional network architecture, in which individual network devices make traffic decisions based on their configured routing tables. In this paper, I built and tested an SDN load balancer and firewall module using the Floodlight controller.

Motivation & Objective

• To design a centralized, programmable approach to network load balancing and firewalling using SDN principles.
• To address the limitations of traditional, decentralized network architectures that require manual configuration and lack agility.
• To implement and test a functional SDN-based load balancer and firewall module using the Floodlight controller.
• To demonstrate how SDN enables rapid response to changing business network needs through dynamic policy enforcement.

Proposed method

• Utilized the Floodlight SDN controller as the central management point for network control and policy enforcement.
• Implemented custom modules within Floodlight to handle load balancing by distributing incoming traffic across multiple backend servers.
• Developed a firewall module that applies access control rules based on source/destination IP and port, enforcing security policies centrally.
• Used OpenFlow protocol to communicate between the controller and network switches, enabling dynamic rule installation and modification.
• Designed the system to allow real-time reconfiguration of load distribution and access policies from a single control console.
• Tested the implementation in a simulated network environment to validate functionality and responsiveness.

Experimental results

Research questions

• RQ1 How can a centralized SDN controller effectively manage both load balancing and firewalling functions in a single network architecture?
• RQ2 What are the performance and scalability implications of integrating load balancing and firewalling within a single SDN framework?
• RQ3 Can the Floodlight controller efficiently handle dynamic rule updates for load distribution and access control without introducing latency?
• RQ4 How does the proposed system improve network agility compared to traditional, device-level configuration approaches?
• RQ5 What are the practical challenges in implementing and testing such a combined SDN service module?

Key findings

• The implemented SDN-based load balancer successfully distributed incoming traffic across multiple backend servers with minimal configuration overhead.
• The firewall module effectively enforced access control policies by filtering traffic based on predefined rules, demonstrating centralized security enforcement.
• The system enabled dynamic reconfiguration of load balancing and firewall rules through the central controller, enhancing network responsiveness.
• Testing confirmed that the Floodlight controller could manage both services concurrently without significant performance degradation.
• The solution demonstrated the feasibility of combining load balancing and firewalling in a single, programmable SDN framework, improving network management efficiency.