A low cost compact network TAP device with Raspberry Pi 4

The communication of multiple networks in different locations is an open problem since the networks include various devices and applications. There is a necessarity to monitor the network to detect any kind of attacks or problems. Determining which device is the source of the problem and vulnerability is also a problem. Network TAP devices are positioned between network devices, allowing for device-based monitoring of communications across the entire network. With this feature Network TAP devices play a main role in network security, network visibility, network monitoring, forensics, etc. Typically, Network TAP devices copy all packets transmitted between two network devices and allow the network authority to monitor the packets through the monitoring port. However, TAP devices available in the market are high cost devices. At this point, we propose a low-cost network TAP device using Raspberry Pi 4. This article provides theoretical and practical contributions into the network TAP literature and includes a method that can be easily implemented for end users. The proposed TAP device has a cost between 1/8 to 1/30 compared to the prices in the market. The device, with its flexible software-based solutions, extensible storage options with any portable disk, can be adapted into various test cases. In addition, the proposed TAP device offers the opportunity to monitor the captured packets via a monitor or remote connection without a computer. Unlike traditional TAP devices, it captures and records packets independently without the necessary of an external computer connection, while enabling real-time monitoring through connected monitor. Experimental studies are carried out at CENTER SAU testbed center with our proposed TAP device and ET2000 device from Beckhoff. When the pcap files obtained from the experimental studies were examined, it was observed that the same packets were captured, therefore the proposed TAP device captured all packets lossless. The results show that the device is a cost-effective alternative for corporate and individual users.