Recommend best security practices to achieve business objectives based on risk assumptions.

Introduction

The process of implementing security frequently opens one’s eyes to other forms of security not previously considered. In this two-part assignment, you should experience just that. This assignment focuses on a model of implementing security in layers, which, in many cases, requires a network that is designed accordingly.

The specific course learning outcome associated with this assignment is:

• Recommend best security practices to achieve business objectives based on risk assumptions.

Instructions

Design a network that incorporates the following:

• One corporate site (Chicago).
  • All servers exist here (web server, file server, print server, mail server, FTP server).
  • Connection to the Internet (50 MBps).
  • 300 employees who only need access to local corporate resources and the Internet.
• One remote site (8 miles away).
  • 20 employees who need access to all resources at corporate, plus the Internet.
  • Connection to the Internet (3 MBps).

Part 1

Use Microsoft Visio or an open-source alternative, such as Dia Diagram Editor, to:

• Create a network diagram with defense in depth in mind, citing specific, credible sources that support the design and depicting at least four-fifths of the following:
  • All necessary network devices (routers, switches and/or hubs, firewalls, VPNs, proxies, and others).
  • The interconnections between network devices.
  • Connections to end-user (client) devices (desktops, laptops).
  • Connections from the Internet cloud to the network input.

Part 2

Write a 6-10 page paper in which you:

• Describe the flow of data through the network, citing specific, credible sources.
  • Assume data begins at the remote site.
  • Data flow may be monitored by an IDS.
• Explain all three elements of the CIA triad and how isolating by network functions helps deliver a layered approach, citing specific, credible sources that support your assertions and conclusions.
• Support your main points, assertions, arguments, or conclusions with at least four specific and credible academic sources synthesized into a coherent analysis of the evidence.

Introduction

Network security design using defense in depth provides a structured approach to protecting organizational assets through multiple layers of security controls. In modern enterprise environments, threats continue to evolve, which makes it necessary to implement comprehensive and adaptive security strategies. The process of designing layered security often reveals additional vulnerabilities that may not have been initially identified. Therefore, organizations must align their network architecture with security principles that support both protection and operational efficiency. This paper presents a network design for a corporate site in Chicago and a remote site, followed by an analysis of data flow, intrusion detection, and the application of the CIA triad within a layered security framework.

Network Architecture Overview

The proposed network security design using defense in depth incorporates a centralized corporate site that hosts all critical servers, including web, file, print, mail, and FTP services. These servers are placed within a segmented server zone to reduce exposure to unauthorized access. In addition, a demilitarized zone is established to host public facing services, thereby separating them from internal resources.

At the corporate site, a high capacity firewall protects the network perimeter and manages traffic from the Internet connection operating at fifty megabits per second. Behind the firewall, internal segmentation divides the network into functional areas such as user networks, server networks, and management networks. This segmentation enhances security by limiting lateral movement within the network.

The remote site, located eight miles away, connects securely to the corporate network through an encrypted virtual private network tunnel. This connection allows twenty employees to access corporate resources while maintaining data confidentiality. Furthermore, the remote site includes its own firewall and router to manage local traffic and provide Internet access at three megabits per second.

Network Devices and Layered Security Controls

Network security design using defense in depth relies on multiple interconnected devices that enforce security policies at different layers. Routers at both sites manage data routing and ensure efficient communication between networks. Switches provide connectivity for end user devices while supporting segmentation through virtual local area networks.

Firewalls serve as the primary line of defense by filtering traffic based on predefined rules. In addition, proxy servers enhance security by controlling web access and masking internal network addresses. Intrusion detection systems are deployed to monitor network activity and detect potential threats in real time.

Furthermore, each layer of security contributes to overall protection by addressing specific risks. For example, perimeter defenses prevent unauthorized access from external sources, while internal controls protect sensitive data within the network. Consequently, the integration of these devices creates a robust and resilient security architecture.

Data Flow from the Remote Site

The flow of data in network security design using defense in depth begins at the remote site when a user initiates a request to access corporate resources. Initially, the data is transmitted from the user device to a local switch, which forwards it to the site router. The router then directs the traffic to the firewall for inspection.

After passing firewall checks, the data is encrypted and transmitted through the virtual private network tunnel to the corporate site. Upon arrival, the corporate firewall decrypts and inspects the data to ensure compliance with security policies. The data is then routed through an intrusion detection system, which monitors for anomalies and potential threats.

Subsequently, the data reaches the appropriate server within the segmented network environment. Responses follow the same secure path in reverse, ensuring that communication remains protected throughout the process. This layered data flow enhances security by applying multiple checkpoints that verify and protect information at each stage (Stallings, 2020).

Role of Intrusion Detection Systems

Intrusion detection systems play a critical role in network security design using defense in depth by providing continuous monitoring and threat detection. These systems analyze network traffic patterns to identify suspicious behavior that may indicate cyber attacks. By detecting anomalies early, intrusion detection systems enable timely response to potential threats.

In this network design, the intrusion detection system is positioned within the corporate network to monitor traffic from both the Internet and the remote site. This placement ensures that all incoming data is analyzed before reaching sensitive resources. In addition, alerts generated by the system support rapid incident response and mitigation.

Moreover, intrusion detection systems enhance overall security visibility by providing insights into network activity. These insights help organizations identify vulnerabilities and improve their security posture. Therefore, IDS technology is an essential component of a layered security strategy.

Application of the CIA Triad

The CIA triad forms the foundation of network security design using defense in depth by addressing confidentiality, integrity, and availability. Confidentiality ensures that sensitive data is accessible only to authorized users, which is achieved through encryption, access controls, and secure communication channels.

Integrity focuses on maintaining the accuracy and reliability of data by preventing unauthorized modifications. This is supported by mechanisms such as hashing and secure transmission protocols. Availability ensures that systems and data remain accessible when needed, which requires redundancy, fault tolerance, and efficient resource management (Whitman and Mattord, 2021).

By isolating network functions through segmentation, the design enhances each element of the CIA triad. For example, separating server zones from user networks reduces the risk of unauthorized access, thereby supporting confidentiality. Similarly, monitoring systems and redundancy measures ensure data integrity and availability. Consequently, the CIA triad is effectively implemented within the layered security framework.

Defense in Depth and Functional Isolation

Defense in depth emphasizes the use of multiple security layers to protect against a wide range of threats. In this network design, layers include perimeter defenses, internal segmentation, encryption, and monitoring systems. Each layer addresses specific vulnerabilities and contributes to overall security.

Functional isolation further strengthens this approach by separating network components based on their roles. For instance, placing public facing servers in a demilitarized zone limits exposure to internal systems. Similarly, using virtual local area networks separates user groups and reduces the spread of potential attacks.

Research indicates that layered security significantly reduces the likelihood of successful cyber attacks by creating multiple barriers for attackers (Anderson, 2020). Therefore, combining defense in depth with functional isolation enhances both security and resilience.

Alignment with Business Objectives

Network security design using defense in depth must align with organizational goals to ensure that security measures support business operations. Effective security strategies protect critical assets while maintaining system performance and usability. In this case, the network design supports efficient communication between the corporate and remote sites while ensuring secure access to resources.

In addition, the use of scalable technologies allows the organization to adapt to future growth and evolving security threats. By integrating security into the network architecture, the organization can achieve both protection and operational efficiency. Consequently, aligning security design with business objectives enhances overall organizational performance.

Conclusion

Network security design using defense in depth provides a comprehensive framework for protecting enterprise networks and ensuring secure communication across distributed environments. By implementing multiple layers of security controls, including firewalls, intrusion detection systems, and encryption, the proposed design effectively mitigates risks. The analysis of data flow demonstrates how security measures protect information at each stage of transmission. Furthermore, the application of the CIA triad ensures that confidentiality, integrity, and availability are maintained throughout the network. Ultimately, a layered security approach enhances resilience, supports business objectives, and enables organizations to operate securely in a complex digital landscape.

References

Anderson, R. Security engineering a guide to building dependable distributed systems Wiley

Stallings, W. Network security essentials applications and standards Pearson

Whitman, M. and Mattord, H. Principles of information security Cengage Learning

Zhang, Y. and Paxson, V. Detecting stepping stones intrusion detection IEEE Symposium