Cloud Firewall: Azure Firewall vs AWS Network Firewall for Cloud Traffic Protection 

Choose Azure Firewall when your core workloads sit in Microsoft Azure, and choose AWS Network Firewall when your traffic patterns are built around VPCs, Transit Gateway, and native AWS routing. Both products protect cloud traffic with managed firewalling, threat filtering, and centralized policy control. The better option is less about raw feature count and more about where your apps live, how your network is routed, and how much operational pain you can tolerate.

TLDR: Azure Firewall is usually the cleaner fit for Azure-centric teams that want tight integration with Virtual Networks, Microsoft Sentinel, and Azure Policy. AWS Network Firewall fits AWS-heavy environments that need stateful inspection across many VPCs through Transit Gateway. For example, a retail company running 70% of workloads in AWS and 30% in Azure may cut inspection complexity by routing AWS east-west traffic through AWS Network Firewall, while using Azure Firewall only for Azure spoke networks. In many real deployments, centralizing inspection can reduce exposed public endpoints by 40% or more, which is often the fastest security win.

What These Cloud Firewalls Actually Do

A cloud firewall sits between workloads, users, the internet, and other networks. It inspects traffic, blocks risky flows, and applies rules at scale. Unlike old hardware firewalls, these services are managed by the cloud provider. You do not rack gear, patch appliances, or worry about failed fans at 2 a.m.

Azure Firewall is a managed network security service for Azure Virtual Networks. It supports network rules, application rules, NAT rules, threat intelligence, TLS inspection in Premium, URL filtering, IDPS, and integration with other Microsoft security tools.

AWS Network Firewall is a managed firewall service for Amazon VPCs. It supports stateless and stateful inspection, Suricata-compatible rules, domain filtering, intrusion prevention patterns, and routing through AWS networking tools such as Transit Gateway and Gateway Load Balancer patterns.

Azure Firewall: Strengths and Weak Spots

Azure Firewall feels most useful when you already run a hub-and-spoke Azure network. You place it in a central hub Virtual Network, route traffic from spoke networks through it, and manage policy from one place. This model is common for enterprises with many subscriptions and teams.

Key strengths include:

• Strong Azure integration: It works well with Azure Virtual Network, Azure Monitor, Microsoft Sentinel, Defender for Cloud, and Azure Policy.
• Simple central policy: Firewall Policy lets teams manage rules across regions and environments.
• Premium inspection features: TLS inspection, IDPS, web categories, and URL filtering help secure outbound and east-west traffic.
• Threat intelligence: Microsoft threat feeds can alert on or deny traffic to known bad IPs and domains.

The catch is that Azure Firewall can feel expensive when it sits idle, especially in smaller environments. You pay for deployment time and data processed. If you only need basic subnet segmentation, Network Security Groups may do the job for far less money.

Another annoyance is rule hygiene. Large Azure Firewall policies can become messy fast. If every team adds exceptions for “temporary” testing, you may end up with hundreds of stale rules. Expect to spend real time tagging rules, setting owners, and reviewing logs.

AWS Network Firewall: Strengths and Weak Spots

AWS Network Firewall shines in AWS accounts with many VPCs. It is built around AWS routing, so you can inspect traffic entering and leaving VPCs, crossing between VPCs, or moving through centralized egress points. It pairs well with Transit Gateway when many accounts need shared protection.

Key strengths include:

• Deep VPC routing control: You decide which subnets and routes send traffic through firewall endpoints.
• Flexible rule design: It supports stateless rules for speed and stateful rules for deeper inspection.
• Suricata rule support: Security teams can reuse familiar IPS-style rule formats.
• Good fit for multi-account AWS: Centralized inspection works well with AWS Firewall Manager and Organizations.

Honestly, it feels like AWS gives you power, then hands you a box of routing puzzles. Route tables, firewall endpoints, asymmetric routing, and Transit Gateway attachments must be planned with care. One wrong route can bypass inspection or break return traffic.

Cost also needs attention. AWS Network Firewall charges for endpoints, traffic processed, and sometimes related logging or routing components. In high-throughput environments, small design choices can change the monthly bill by thousands of dollars.

Feature Comparison

Traffic Protection: North-South and East-West

North-south traffic is traffic entering or leaving the cloud. Think internet users reaching an app, workloads calling public APIs, or branch offices connecting through VPN. Both products can inspect this traffic well, but setup differs.

In Azure, teams often use Azure Firewall for outbound control, DNAT for inbound access, and Application Gateway or Web Application Firewall for web apps. In AWS, teams often combine AWS Network Firewall with Application Load Balancer, NAT Gateway, Route 53, and sometimes AWS Web Application Firewall.

East-west traffic is traffic between internal workloads. This is where design gets tricky. Azure Firewall can inspect traffic between spokes if routes force traffic through the hub. AWS Network Firewall can inspect VPC-to-VPC traffic when routes through Transit Gateway and firewall endpoints are correct.

For both platforms, do not assume traffic is inspected just because a firewall exists. Cloud routing decides the path. Logs prove what actually happened.

Logging, Monitoring, and Incident Response

Logs are where firewalls become useful during an incident. Azure Firewall sends logs to Azure Monitor, Log Analytics, and Microsoft Sentinel. This is helpful if your security team already works inside Microsoft’s security stack.

AWS Network Firewall sends logs to Amazon S3, CloudWatch Logs, and Kinesis Data Firehose. This gives teams flexibility, especially if they use third-party SIEM tools or long-term storage in S3.

Metrics matter too. Track denied flows, allowed outbound destinations, top talkers, rule hit counts, and traffic volume by zone or subnet. A rule that never fires for 90 days may be safe to remove. A sudden spike in denied DNS or outbound HTTPS traffic may point to malware, misconfiguration, or a broken deployment.

Cost and Performance Reality

Neither service is “cheap” by default. Both are managed security tools with hourly and usage-based pricing. The good news is that you avoid appliance licensing, hardware support, and manual scaling work. The bad news is that noisy workloads can create ugly bills.

Azure Firewall often makes sense when shared across many spokes, subscriptions, or departments. AWS Network Firewall often makes sense when centralized across many VPCs and accounts. Small teams should compare these services against lighter controls first, such as security groups, Network Security Groups, private endpoints, service endpoints, and restricted egress through NAT plus DNS filtering.

Performance is usually strong, but inspection depth affects latency. TLS inspection, IDPS, and heavy rule sets can add processing time. Test with real traffic before rollout. A lab with 50 requests per second tells you little about a production checkout service handling 5,000 requests per second during a sale.

Which One Should You Pick?

• Pick Azure Firewall if your workloads sit mainly in Azure, your team uses Microsoft Sentinel, and you want centralized control across Virtual Networks.
• Pick AWS Network Firewall if your workloads sit mainly in AWS, your network uses many VPCs, and Transit Gateway is already part of your design.
• Use both if you run serious multi-cloud operations. Do not force all traffic through one cloud just to use one firewall service.
• Use neither as the only control. Pair them with identity, encryption, endpoint security, WAF rules, private connectivity, and least-privilege network design.

Practical Recommendation

Start with traffic maps, not product pages. List your top 20 applications, their inbound sources, outbound destinations, data sensitivity, and latency needs. Then decide where inspection belongs.

If 80% of traffic lives inside Azure, Azure Firewall will likely be simpler and easier to explain during audits. If 80% lives inside AWS, AWS Network Firewall will usually fit better. For a split environment, place inspection close to the workload. That keeps latency lower and avoids paying twice to move traffic across clouds.

The smartest cloud firewall choice is the one your team can operate cleanly every week. Fancy inspection means little if routes bypass it, logs are ignored, or rule changes take three days because nobody understands the policy structure.