The primary function of AWS Network Firewall is to provide a managed network firewall specifically designed for Amazon Virtual Private Cloud (VPC) environments. This service allows users to create and manage rules that control the traffic entering and leaving the VPC, enhancing security by enabling the filtering of both inbound and outbound network traffic. By utilizing AWS Network Firewall, organizations can define stateful and stateless rules to protect their networks against unauthorized access and to enforce compliance protocols.
AWS Network Firewall integrates natively with other AWS services and enables logging and monitoring features to track allowed and denied traffic. It helps ensure that communications within VPCs are secure and controlled, thus playing a crucial role in building a secure network architecture in the cloud.
The other options do not capture the primary purpose of AWS Network Firewall. Protecting application data involves different AWS services and tools, such as AWS Key Management Service (KMS) for encryption. Monitoring web traffic is generally the role of services like AWS WAF or Amazon CloudWatch. Managing SSL/TLS certificates pertains to AWS Certificate Manager, which focuses on handling digital certificates for secure communications, rather than providing network firewall capabilities.