Network Perimeter Defense Architecture: A Case Study

This paper, written as a case study in 2001, documents a comprehensive architecture for defending network resources of a fictitious company. It illustrates an approach to setting up a strong security perimeter. This document was submitted to SANS GIAC to fulfill GIAC Certified Firewall Analyst (GCFW) certification requirements.

This paper is only available in Adobe Acrobat PDF format. You may download it here. The table of contents is listed below for your convenience:

Part 1: Security Architecture
1.1 Assigned Task
1.2 Application Architecture
1.3 Perimeter Defense
1.4 External Connectivity
1.5 Implementation
Part 2: Security Policy
2.1 Assigned Task
2.2 Guiding Principles
2.3 Border Router
2.4 Firewalls
2.5 VPN Configuration
2.6 Applying Policy
2.7 Compliance Monitoring
Part 3: Audit of the Security Architecture
3.1 Assigned Task
3.2 Planning the Assessment
3.3 Assessment of Security Design
3.4 Assessment of Defense Perimeter Implementation
3.5 Assessment of Defense Component Implementation
3.6 Defense Improvement Recommendations
Part 4: Design Under Fire
4.1 Assigned Task
4.2 Targeted Architecture
4.3 Attacking the Firewall
4.4 Denial of Service Attack
4.5 Compromising an Internal System

About the Author

Lenny Zeltser develops products and programs that use security to achieve business results. He is the CISO at Axonius and Faculty Fellow at SANS Institute. Lenny has been leading efforts to establish resilient security practices and solve hard security problems for over two decades. A respected author and practitioner, he has been advancing tradecraft and contributing to the community. His insights build upon real-world experience, a Computer Science degree from the University of Pennsylvania, and an MBA degree from MIT Sloan.

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