user wants a long article about FortiGate VM sizing on Azure. I need to provide comprehensive information. I'll follow the search plan provided in the hints. The plan has three rounds. I'll start with Round One. search results from Round One have provided some initial information. Now, I need to proceed to Round Two for deeper dives into specific topics. The plan includes opening specific relevant pages. I'll start opening those pages. search results provide a good amount of official documentation. Now I need to proceed to Round Two. The plan includes specific searches for troubleshooting, sizing calculators, community discussions, and Azure-specific networking considerations. I'll execute these searches now. have gathered a substantial amount of information from the search results. Now I need to synthesize this into a comprehensive article. The article will cover key sections such as introduction, licensing models, VM types and sizing, network interface considerations, high availability and autoscaling, cost optimization, common pitfalls, and a checklist. I'll structure the article to be informative and practical.izing a FortiGate virtual machine on Microsoft Azure isn't just a technical decision—it's a strategic one that sits at the heart of your cloud's security and performance. A properly sized deployment ensures you're not overpaying for idle capacity or, worse, discovering a throughput bottleneck during a critical traffic spike.
To avoid performance bottlenecks, ensure your chosen size supports Accelerated Networking . This offloads packet processing from the CPU to the NIC, drastically reducing latency and jitter. 2. Matching FortiGate Licenses to Azure Sizes
If you need to upscale your deployment, follow these steps to prevent data loss:
This design can also incorporate , allowing you to maintain compliance while having a backup instance ready to go.
: Pay-as-you-go (PAYG) licenses are tied to VM size changes—resizing may break licensing. BYOL (Bring Your Own License) is more flexible. fortigate vm sizing azure
Use or Ultra Disks to prevent disk I/O bottlenecks. Slow disk write times can cause backpressure on the logging daemon, leading to elevated system memory utilization and triggering FortiOS "Conserve Mode." 6. Verification and Monitoring Strategy
Use the following architectural tiers as a baseline for your deployment planning. Deployment Tier Typical Use Case Recommended Azure Size FortiGate License Key Capabilities Secure SD-WAN, light remote access, minimal DPI. Standard_F2sv2 Standard_D2sv5 VM-02 (2 vCPU) Up to 1.5 Gbps Firewall ~300 Mbps NGFW Medium / Mid-Market Corporate internet edge, active-passive HA hub. Standard_F4sv2 Standard_D4sv5 VM-04 (4 vCPU) Up to 3.5 Gbps Firewall ~800 Mbps NGFW Large / Enterprise Datacenter inspection, high-density IPsec VPN hub. Standard_F8sv2 Standard_D8sv5 VM-08 (8 vCPU) Up to 7.5 Gbps Firewall ~1.8 Gbps NGFW Ultra / High-Performance Multi-tenant core, heavy SSL inspection, cloud DMZ. Standard_F16sv2 VM-16 (16 vCPU) Up to 15 Gbps Firewall ~3.5 Gbps NGFW
Licenses are typically sold by vCPU count (e.g., VM-02, VM-04, VM-08). If you license a (2 vCPUs) but deploy it on a Standard_D4s_v5 (4 vCPUs), the FortiGate will only utilize 2 of those CPUs , wasting half of your Azure compute costs. 4. Performance Expectations
When sizing for HA, you must ensure that is sized identically. Mixing different VM sizes in an active-passive or active-active pair leads to unpredictable failover behavior and is not recommended. user wants a long article about FortiGate VM sizing on Azure
One of the most overlooked aspects of FortiGate-VM sizing on Azure is the each VM size supports. Azure strictly limits the number of NICs per VM based on its instance type.
Always choose a size that supports Azure Accelerated Networking (SR-IOV). This reduces latency and CPU overhead by bypassing the virtual switch.
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) limits how many vCPUs the FortiOS software will actually use. The plan has three rounds
RSS distributes network receive processing across multiple vCPUs, preventing a single core from becoming a bottleneck during high-volume ingress events. Verify that RSS is active within FortiOS to guarantee that traffic flows are evenly balanced across all available vCPU worker threads. Disk Subsystem Sizing (IOPS)
: This Azure feature is essential for high throughput. It offloads network processing to dedicated hardware (FPGA), significantly reducing latency and jitter. Ensure your chosen Azure size supports it.
| Use Case | VM Size | vCPU | RAM (GB) | Max NICs | Est. Real Throughput | |----------|---------|------|----------|----------|----------------------| | (<500 Mbps) | D2s v3 / D2ds v4 | 2 | 8 | 4 | ~500-800 Mbps | | Medium branch (1-2 Gbps) | D4s v3 / D4ds v4 | 4 | 16 | 8 | ~1.5-2 Gbps | | Large branch / DC (2-4 Gbps) | D8s v3 / D8ds v4 | 8 | 32 | 8 | ~3-4 Gbps | | Enterprise / VPN hub (5-8 Gbps) | D16s v3 / D16ds v4 | 16 | 64 | 8 | ~6-8 Gbps | | Heavy SSL inspection (4-6 Gbps) | E8s v3 / E8ds v4 | 8 | 64 | 8 | ~4-5 Gbps |
Not all Azure VM families work well for firewalls. The following are field-proven:
