Network Penetration Testing – Conduct network penetration tests against simulated networks to find vulnerabilities. Methodically work through the penetration testing process of reconnaissance, scanning, exploitation, privilege escalation, maintaining access, and more. Write a detailed report documenting findings. References: The Hacker Playbook 3: Practical Guide To Penetration Testing by Craig Smith; Penetration Testing: A Hands-On Introduction to Hacking by Georgia Weidman.

Implementing a Network Intrusion Detection/Prevention System – Deploy and configure an open-source intrusion detection and prevention system like Snort or Suricata. Configure rules, signatures and monitoring capabilities. Test by launching mock attacks and ensure the system detects and blocks them appropriately. Write documentation on deployment, configuration and testing procedures. References: Snort Cookbook by Tony Singles; Suricata User Guide; Mastering Snort by Douglas Burks.

Design and Implement a Firewall Ruleset – Create detailed firewall design documentation including network diagrams, IP addressing scheme, services allowed, and proposed ruleset. Deploy and configure the firewall with the ruleset using an open-source firewall like pfSense or OPNsense. Test common ports, protocols and services to ensure only permitted traffic can pass through the firewall. References: pfSense: The Definitive Guide by Jim Pingle and Chris Bason; OPNsense documentation.

Secure Network Infrastructure Hardening – Study a real or simulated network and perform a security audit to identify vulnerabilities. Develop a comprehensive plan to harden systems, network devices, and applications based on industry best practices. Implement recommendations like disabling unnecessary services, updating software/firmwares, patching vulnerabilities, configuring secure protocols, access controls, logging/monitoring and more. Document processes. References: CIS Benchmarks; NIST SP 800-123 Guide to General Server Security; DHS Cybersecurity & Infrastructure Security Agency (CISA) guidance.

Design and Implement a VPN – Create design documentation and configure an IPsec or OpenVPN based remote access VPN. Configure encryption, authentication, ACLs and other security features. Test connectivity and verify only authorized access. Install and configure a VPN client and connect from remote machines. Measure performance impact. Document configuration, setup instructions and testing procedures. References: Cisco VPN Configuration Guide; OpenVPN Installation and Configuration Guide; VPN Best Practices for Network Engineers by Michael Fosqua.

Network Security Awareness Training Program – Develop training materials like presentations, documentation, videos etc. to educate users about common threats, secure practices, password security, phishing, social engineering and more. Create mock scenarios to test user understanding. Implement a training system to deliver, track completion and reinforce training over time. Analyze effectiveness of training. Recommend improvements based on analysis. References: SANS Security Awareness Training; Building a Security Awareness Program: 9 Foundational Principles by Kevin Beaver; Implementing an Effective Security Awareness Program by Justin Searle

Design and Implement a Wireless Security Solution – Assess wireless security risks in an organization and design a plan for a secure wireless infrastructure. Configure authentication via RADIUS or captive portal. Encrypt traffic using WPA2 and WPA3 standards. Implement wireless intrusion prevention capabilities. Segregate guest and corporate traffic. Create monitoring and alerting. Test security measures. Configure wireless clients. Document setup and configurations. References: CWSP Certified Wireless Security Professional Official Study Guide by David Coleman and David Westcott; Wireless Security Handbook by Ron Pierce

There are many possibilities for network security capstone projects that allow demonstrating skills across various domains ranging from network and system hardening to intrusion prevention to security awareness. The projects require comprehensive planning, design, implementation, testing and documentation. Defining the scope and focusing on practical real-world scenarios are important for a successful capstone. The references provided are a starting point for further research and understanding industry best practices. Network security capstone projects provide hands-on experience with network defense methodologies and allow demonstrating mastery of core security concepts.