3.1. Network Security Controls

Implementing robust network security controls is crucial for protecting your AWS environment. These controls act as virtual firewalls and protective barriers at various layers of your network. This section will explore the primary AWS services for implementing network security controls, from instance-level firewalls to advanced threat protection at the network edge.

Scenario: You need to protect your web application from common web exploits. Your application servers need to communicate with a database, but the database should not be directly accessible from the internet.

💡 First Principle: Deploying multiple layers of network security controls at different points of traffic flow fundamentally protects resources from unauthorized access, malicious attacks, and data exfiltration through a "defense-in-depth" strategy.

This section explores the primary AWS services for implementing network security controls.

⚠️ Common Pitfall: Relying on a single security control. A robust security posture uses a defense-in-depth approach, layering controls at the network, host, application, and data levels.

Key Trade-Offs:

• Granularity vs. Management Overhead: More granular security controls (e.g., per-instance Security Groups) offer tighter protection but can increase management complexity compared to broader subnet-level controls (e.g., NACLs).

Reflection Question: How does deploying multiple layers of network security controls (e.g., Security Groups, AWS WAF) at different points of traffic flow fundamentally protect resources from various threats through a "defense-in-depth" strategy?