Advanced network technologies, such as Software-Defined Networks (SDN) and the Internet of Things (IoT), are now part of the Internet. Exploiting related vulnerabilities, attackers may compromise confidentiality, integrity and/or availability of systems to harm human beings, businesses or governments. It is important to understand the most relevant attacks on the Internet and the state-of-the-art defences, including how novel Internet technologies work and the security challenges they create. The professional needs to be able to perform a critical assessment of attacks and comparison of approaches proposed to mitigate them. Besides strengthening the students' background, this paper prepares them to conduct research on the topic of network security.

This is a discussion-driven, synchronously taught paper. Students are expected to attend the two lectures each week (note that this is not a NET paper). When it is not possible to attend in person, the student will be able to participate via Zoom. In both cases, student participation will be recorded using the Xorro system.

The paper is organised into four parts. It begins with an overview of network security, revising Internet operation and security principles. The second part covers state-of-the-art knowledge about four of the most important network security issues: prefix hijacking, vulnerability scanning, botnets, and Distributed Denial-of-Service (DDoS). The third part is about recent network technology advances (Internet of Things - IoT and Software-Defined Networks - SDN), and the novel security challenges and opportunities they create. The last part, building on the previous three, uses active student participation and in-class discussions via seminars to connect research advances on network security with real-world applications.