A company has an Azure virtual network with multiple subnets. They want to centrally inspect and log all outbound traffic to the internet. They also need to allow or deny traffic based on domain names (FQDNs). Which Azure resource should they deploy?
Azure Firewall is a fully managed, cloud-native firewall that can filter outbound internet traffic using application rules based on destination FQDNs, allowing or denying requests by hostname rather than only IP. It captures comprehensive diagnostic logs via diagnostic settings to Azure Monitor, where you can query the AzureDiagnostics table for denied/allowed flows. This combination of FQDN-level control and centralized, queryable logging directly meets the stated requirement.
Why this answer
Azure Firewall is a managed, cloud-native network security service that provides centralized outbound traffic inspection and logging. It supports application rules based on fully qualified domain names (FQDNs), enabling allow or deny decisions for outbound traffic to the internet using Layer 7 (application layer) filtering, which meets both requirements directly.
Exam trap
The trap here is that candidates often confuse Azure Firewall with Network Security Groups, mistakenly thinking NSGs can filter by domain names because they associate 'network security' with all traffic control, but NSGs lack Layer 7 capabilities and cannot inspect or filter based on FQDNs.
How to eliminate wrong answers
Option B (NVA from Azure Marketplace) is wrong because, while an NVA can inspect and log traffic and filter by FQDNs, it is not a native Azure managed service; it requires manual deployment, maintenance, and scaling, and does not provide the same level of integrated logging and central management as Azure Firewall for this specific use case. Option C (Azure Application Gateway with WAF) is wrong because it is designed for inbound HTTP/HTTPS traffic load balancing and web application protection, not for outbound traffic inspection or domain-based filtering of all outbound internet traffic. Option D (Azure Network Security Groups) is wrong because NSGs operate at Layer 3/4 (network and transport layers) and cannot filter traffic based on domain names (FQDNs); they only support source/destination IP addresses, ports, and protocols.