Networks and Communications Security

Go to Course: https://www.coursera.org/learn/network-security-communications-sscp

Introduction

### Course Review: Networks and Communications Security on Coursera #### Overview The **Networks and Communications Security Course** on Coursera is an insightful and comprehensive program that explores the vital aspects of network security in today's interconnected world. Given the ever-growing reliance on electronic communications for business, personal, and governmental functions, understanding the security challenges that accompany these advancements is crucial. This course serves as an excellent foundation for individuals seeking to enhance their knowledge about securing networks and communications. #### Course Content and Structure The course delves into essential topics related to both public and private communication networks. The syllabus is structured into five modules, each designed to build upon the knowledge acquired in the previous ones: 1. **Apply the Fundamental Concepts of Networking**: This module introduces the foundational principles of networking, using the Open Systems Interconnection (OSI) model and the TCP/IP model as guiding frameworks. 2. **Securing Ports and Protocols**: Here, students gain in-depth knowledge of various protocols that underpin common Internet services. It emphasizes understanding the ports these protocols utilize, as well as security considerations necessary for their protection. 3. **Network Attacks and Countermeasures**: This critical module focuses on various network vulnerabilities and the countermeasures available. Drawing on the MITRE ATT&CK framework, participants learn to identify potential attacks and strategize defenses. 4. **Manage Network Security**: Covering the tools, protocols, and procedures necessary for securing networks, this module discusses devices like firewalls and VLANs, promoting a holistic approach to network security management. 5. **Review**: The final module consolidates everything learned, emphasizing the importance of continuous adaptation to evolving threats in a globalized network environment. #### Learning Objectives By the end of the course, participants should be able to: - Recognize the different layers of the OSI model and understand the security implications at each level. - Identify commonly used ports and protocols. - Choose suitable countermeasures against various network attacks. - Summarize best practices for creating a secure network environment. #### Target Audience and Experience Required This course is explicitly designed for beginners, making it accessible for anyone interested in understanding network security, regardless of their prior experience. Whether you are a student, a professional looking to transition into a security role, or simply someone interested in the mechanics of network security, this course will cater to your learning needs. #### Why I Recommend This Course 1. **Comprehensive Curriculum**: The course covers a wide range of relevant topics that encapsulate both theoretical knowledge and practical applications, making it suitable for learners aspiring to gain a solid foundation in network security. 2. **Expert Instruction**: Students benefit from guidance from seasoned educators who are well-versed in their fields, ensuring that the course content is not only accurate but also aligned with current industry standards and practices. 3. **Interactive Learning**: The blend of theoretical discussions with practical assignments engages students and allows them to apply what they have learned in real-world scenarios, solidifying their understanding. 4. **Flexible Learning Environment**: Being online, the course allows participants to learn at their own pace. This is particularly advantageous for those balancing work or other commitments while looking to expand their skill set. 5. **Recognition of Current Security Issues**: The curriculum addresses modern security challenges faced by organizations, focusing on both traditional and sophisticated threats, preparing learners for the increasingly complex landscape of network security. #### Conclusion In conclusion, the **Networks and Communications Security Course** on Coursera is an invaluable resource for anyone looking to delve into the intricacies of network security. With a structured approach that builds essential knowledge and practical skills, it empowers participants to effectively navigate the challenges posed by today's security threats. I highly recommend this course to both newcomers and those wishing to refine their expertise in networks and communications security.

Syllabus

Networks and Communications Security

Course 5: Network and Communications Security Welcome to course five: network and communication security. As we know, the explosive growth in networks, connectivity, and communications has paved the way for unprecedented transformation of business, personal, and government services into electronic, web enabled forms. This growth in e-business and e-commerce greatly expanded the threat surface. Fraudsters, criminals, unscrupulous business competitors, nation states, and non-nation state actors can take harmful actions against others worldwide. For decades, the world has operated on what is basically a network monoculture. One set of protocols and standards are used to power most of the internet, the worldwide, web e-commerce, and e-business. These standards include the open systems interconnection seven layer model from international organization for standardization and transmission. And the control protocol over internet protocol model from internet engineering taskforce. Almost every laptop, many smart devices, and other such end points use these standards to communicate with servers, and applications, and businesses, and governments. Therefore these models, or protocol stacks become our map of the threat surface. Security professionals need to have a solid understanding of modern networks and internet work concepts, techniques, technologies, and security issues. Their work is like police patrols, because they need to be familiar with the neighborhood's environment. Security professionals need to know the best ways to keep the neighborhood secure and to defend against attacks. The need for such a policing mentality is particularly urgent if the company has limited or no remote visibility into its operational technology systems. For this course, in module one, we start with a brief orientation to the network neighborhood, through the open systems interconnection seven layer, and transmission control protocol over internet protocol models. Then, we dive into all eight layers of this combined protocol stack. Introducing the key technologies at each layer and their regular use. In module two, we look at the various protocols that run on top of this architecture. In module three, we focus on attack and defensive strategies and tactics and build on the industry leading approach to put threat surface analysis into both the attackers and defenders operational context. In the last module, we bring these ideas together into a network security management and monitoring perspective. Now, let's discuss these four modules in detail. Course 5 Learning Objectives After completing this course, the participant will be able to:  L5.1 - Recognize layers of the OSI model, their functions and attacks present at each layer. L5.2 - Identify commonly used ports and protocols. L5.3 - Select appropriate countermeasures for various network attacks. L5.4 - Summarize best practices for establishing a secure networked environment. Course Agenda Module 1: Apply the Fundamental Concepts of Networking (Domain 6 - Network and Communications Security) Module 2: Securing Ports and Protocols (Domain 6 - Network and Communications Security) Module 3: Network Attacks and Countermeasures (Domain 6 - Network and Communications Security) Module 4: Manage Network Security (Domain 6 - Network and Communications Security) Who Should Take This Course: Beginners Experience Required: No prior experience required

Let’s build on the 7-layer foundation that module 1 provided us by taking a deeper look at how some of the larger-scale processes work on the internet. Higher-level protocols provide the services that organizations tend to think about when they design workflows and business processes to be email-enabled, cloud-hosted or distributed across a dynamic computing environment.  Messaging, email, file transfer and of course the World Wide Web itself all depend upon these protocols being reliable.  Let’s take a closer look at some of these protocols, the ports they use and a few of the architectural and security considerations for their use and protection. 

Modules 1 and 2 showed us how the simple tool of abstraction, done layer by layer, helps designers and architects start with simple foundational ideas and build powerful, elaborate and incredibly functional systems as a result. We also saw how abstraction provides you (the defensive analyst) with a powerful tool to look at the threats facing the entire organization from almost any level within the protocol stacks, the overall IT architecture and the OT architectures as well.   That process isn’t done yet. Module 3 will start with a walkthrough of MITRE’s ATT&CK framework. As you’ll see, it’s a way of thinking about attacks and about the defenses you want to put in place to stop them or slow them down. It’s also a knowledge base, and a gateway to the growing world-wide community of users, contributors, researchers and security professionals that collaborate through and around its resources. In MITRE’s words, it is “open and available to any person or organization for use at no charge.” Clearly, attackers know of ATT&CK, and the majority of them, no doubt, make excellent use of it!  But remember what Kerckhoffs and Shannon said about encryption systems and the need to protect one’s keys at all costs — this holds true for everything else in cyber defense. Your enemies will know far, far more about how to attack systems like yours than you currently know about how to defend against them. So, it’s probably time to borrow a page from the attackers’ playbook and start digging deeper into resources like ATT&CK.  That will be the start of module 3’s journey. We’ll take a closer look at mitigations to many of those common exploit situations as they pertain to networks. 

Network security comprises the set of devices, protocols and procedures used to protect the network infrastructure itself, the services and data that ride on top of the network, their users and the organization as a whole from various forms of security compromise.  As you might expect, physical and administrative security measures play just as much a role as do the technical or logical controls. Building on the previous three modules, it’s time to take a closer look at some of the common devices, protocols and services used to secure networks, services and data.  These include firewalls, proxies, virtual LANs (VLANs) and strategies for segmenting a network into security domains. To be most effective, these security features should be part of the overall network from its earliest design phases; when added into existing networks, it’s worth letting an up-to-date security assessment of the network identify the most urgent problems to solve. Virtualization technologies allow for networks and their security to be modeled and directed by software, offering the security and network engineering team not only improved visibility of network security issues, but also more powerful ways to manage the security configuration of each device or system on the network. Using software defined security thus becomes a powerful way to take advantage of a software-defined network, as we’ll see later in this section.  

Before the days of networks, it was much, much easier to keep information systems safe and secure. As soon as we started interconnecting them, you might say, the threat surface went global. That’s what this chapter has taken a deep and broad look at.   We started with the architectural concepts on which the internet is built and how these concepts across the seven layers of ISO’s Open Systems Interconnection model work together to provide systems builders with standards and practices to meet. This model is also useful when identifying threat surfaces, performing threat modeling and analysis and in implementing a defensive strategy. The IETF’s network model, known as TCP/IP, complements the OSI 7-Layer model; together both are powerful intellectual forces in the systems and security marketplaces. Their layers of abstraction and their use of encapsulating functions into protocols has meant that for over 40 years the internet has continued to provide services as it has scaled out to support billions of end users around the world.  Security in a networking environment must recognize that attacks can start at any level, from the physical layer of cables and wireless connections to the applications layer and beyond. More importantly, a growing number of very damaging attacks are being conducted by advanced persistent threat (APT) actors, who demonstrate a degree of technical skill and operational sophistication rivaling that of many nations’ security and intelligence services. Even the smallest of organizations, such as a SOHO startup, can find itself swept up in an APT’s campaign of attack. These attacks often use fraud as a major ingredient, which they achieve by injecting falsified data such as invoices, transactions or even database updates directly into target systems, and, in most cases, all by way of remote access over the internet. The MITRE ATT&CK framework, as we saw, provides a continually updated set of current threat intelligence, attack modeling and mitigation strategies to help deal with network attack across enterprise, mobile and industrial control or operational technology systems.  From software-defined networks and collaboration platforms to traditional remote access capabilities, dealing with COVID-19 has demonstrated how much our modern world depends upon reliable, safe and resilient internetworking to get business and governance securely conducted. It has demonstrated the reliance of many business continuity plans on cloud-hosted, internet-powered virtualization of organizations, processes, resources and management functions. These demands for security and safety online will only continue to grow; this chapter has provided insights that can help security professionals make sure that their organization can meet those demands.