Securing the Network

KA Network Security | July 2021

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The Cyber Security Body Of Knowledge

www.cybok.org

INTRODUCTION

The ubiquity of networking allows us to connect all sorts of devices and gain unprecedented access to a whole range of applications and services anytime, anywhere. However, our heavy reliance on networking technology also makes it an attractive target for malicious users who are willing to compromise the security of our communications and/or cause disruption to services that are critical for our day-to-day survival in a connected world. In this chapter, we will explain the challenges associated with securing a network under a variety of attacks for a number of networking technologies and widely used security protocols, along with emerging security challenges and solutions. This chapter aims to provide the necessary background in order to understand other knowledge areas, in particular the Security Operations & Incident Management CyBOK Knowledge Area [1] which takes a more holistic view of security and deals with operational aspects. An understanding of the basic networking protocol stack and popular network protocols is assumed. Standard networking text books explain the fundamentals of the layered Internet Protocol suite [2, 3].

This chapter is organized as follows. In Section 1, we lay out the foundations of this chapter and define security goals in networked systems. As part of this, we also outline attackers and their capabilities that threaten these goals. In Section 2, we describe six typical networking scenarios that nicely illustrate why security in networking is important, and achieving it can be non-trivial. We then discuss the security of the various networking protocols in Section 3, structured by the layered architecture of the Internet protocol stack. In Section 4, we present and discuss several orthogonal network security tools such as firewalls, monitoring and Software Defined Networking (SDN). We complete this chapter with a discussion on how to combine the presented mechanisms in Section 5.