Design of an Isolated and Low-Cost Raspberry Pi-Based IoT Network Infrastructure Against ARP Spoofing and Man-in-the-Middle Attacks

Abstract

This study presents the design and implementation of a low-cost, isolated network infrastructure to protect IoT devices in home and small-scale business environments against ARP spoofing and Man-in-the-Middle (MitM) attacks. The proposed system operates on a Raspberry Pi and establishes a logically separated IoT network, preventing devices on the primary home or corporate network from directly accessing IoT devices. This segmentation enhances security by reducing the attack surface and limiting lateral movement. Network traffic within the isolated environment is monitored in near real time. ARP packets are captured, parsed, and analyzed using a custom-developed algorithm. Based on the analyzed data, the system generates a dynamic risk score to assess the likelihood of ARP spoofing or MitM attacks. When predefined threshold conditions are met, alerts are triggered. In this study, alerts were used for monitoring and evaluation purposes; however, the architecture is designed to enable seamless integration with firewall systems or automated response mechanisms. The system was tested under both normal and attack scenarios. Experimental results demonstrated that risk scores increased significantly during attack conditions, successfully triggering alerts. Additionally, a user-friendly web interface was developed to facilitate monitoring and management. Overall, the findings indicate that the proposed solution provides an affordable, practical, and effective security mechanism for resource-constrained environments.