4.1.4. Network Access Analyzer

Network Access Analyzer identifies potential network access paths to specific resources, enabling network specialists to proactively verify network segmentation and detect unintended network exposure.

Scenario: You have a critical database server in a private subnet that should only be accessible from specific application servers in another subnet. You need to verify that no unintended network access paths exist to your database from other parts of the VPC or connected networks.

For network specialists, it's crucial to verify that network configurations truly block unintended access paths and that network segmentation is working as designed. Manually analyzing complex VPC configurations can be prone to human error.

Network Access Analyzer is a feature within AWS Network Manager that analyzes the network configuration of your VPC and connected networks (e.g., peered VPCs, Transit Gateways, VPNs) to identify potential network access paths to specified resources.

Key Features of Network Access Analyzer:

• Path Analysis: You specify a source and a destination (EC2 instance, Elastic Network Interface (ENI), load balancer, VPN gateway, Direct Connect Gateway, IP address).
• Connectivity Determination: It reports whether the resources are reachable and provides details of the network path if reachable.
• Root Cause Identification: If not reachable, it pinpoints the exact blocking component (e.g., a specific Security Group rule, a missing route table entry, a NACL rule).
• Supported Resources: Works across VPCs, VPC peering connections, Transit Gateways, VPNs, and Direct Connect connections.
• Proactive Analysis: Can be used to verify network configurations before deployment.
• Managed Service: AWS manages the underlying analysis engine.

Practical Implementation: Using Network Access Analyzer (Conceptual)

# 1. Create a path analysis
aws ec2 create-network-insights-path \
#   --source-ip 10.0.1.10 \
#   --destination-ip 10.0.2.20 \
#   --protocol tcp \
#   --destination-port 5432 \
#   --tag-specifications 'ResourceType=network-insights-path,Tags=[{Key=Name,Value=AppToDBPath}]'

# 2. Start the analysis
aws ec2 start-network-insights-analysis \
#   --network-insights-path-id network-insights-path-0abcdef1234567890 \
#   --tag-specifications 'ResourceType=network-insights-analysis,Tags=[{Key=Name,Value=AppToDBAnalysis}]'

⚠️ Common Pitfall: Relying solely on manual review of complex network configurations. Human error is inevitable, and Network Access Analyzer can catch subtle misconfigurations that lead to unintended access.

Key Trade-Offs:

• Automated Analysis vs. Manual Effort: Network Access Analyzer automates complex path analysis, saving significant manual effort but requiring understanding of its output.

Reflection Question: How does Network Access Analyzer, by analyzing network configurations and identifying all potential access paths to specific resources, fundamentally enable you as a Network Specialist to proactively verify network segmentation and detect unintended network exposure in your AWS environment?