Fortigate Vm Sizing Azure

: Determines the parallel processing capacity for traffic and security inspection (IPS, Antivirus, Application Control).

FortiGate supports various instance families, primarily leveraging or General Purpose (D-series) . Feature Need Recommended Azure Series Standard DPI D-Series (e.g., D2s_v3, D4s_v3) Good balance of compute and memory for general UTM tasks. High Performance DPI F-Series (e.g., F4s, F8s)

: Shut down the VM from the Azure Portal, navigate to Availability + Scale > Size , select the new instance, and power it back on.

💡 If you anticipate high growth, size your Azure VM for your "future" needs but use a BYOL license that allows for easy CPU upgrades without redeploying the instance.

FortiGate on Azure supports various VM families, each with a , which can be a critical factor.

Unlike on-premises hardware with fixed ASIC chips, FortiGate VM (FGT-VM) relies entirely on allocated from Azure compute resources. Sizing directly impacts: fortigate vm sizing azure

This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later.

: Always over-provision by one VM size in Azure—you can scale down later, but undersizing causes production packet loss. Use Azure’s reserved instances for 1-3 year commitment to reduce cost.

:

| Estimated Traffic Throughput | Recommended VM Tier (Approx) | vCPU / RAM | Notes | | :--- | :--- | :--- | :--- | | | Standard D2s_v5 | 2 vCPU / 8GB | Good for VPN hub or small spoke. | | 1 - 2 Gbps | Standard D4s_v5 | 4 vCPU / 16GB | Common mid-size hub. Enable Accelerated Networking. | | 3 - 5 Gbps | Standard D8s_v5 | 8 vCPU / 32GB | Ideal for heavy inspection/UTM. | | > 5 Gbps | Standard D16s_v5 or Fxs_v4 | 16+ vCPU | Check Azure bandwidth caps carefully here. |

Intense SSL/TLS decryption, heavy threat protection, and high-throughput environments. : Determines the parallel processing capacity for traffic

Scans files and traffic on the fly without buffering the entire payload. This mode maximizes throughput for Antivirus, IPS, and Application Control.

To ensure long-term stability and performance of your FortiGate cluster in Azure, follow these architectural best practices:

Verify if memory exhaustion is forcing the unit into conserve mode: diagnose hardware sysinfo memory

To get the performance you sized for, you must enable specific features:

: Expect a brief period of downtime during the restart. High Performance DPI F-Series (e

High-performance instances (e.g., Standard_F2 , Standard_F4 ) are often preferred for firewall workloads because they offer a high CPU-to-NIC ratio and strong compute power for packet inspection.

These are typically the best choice for network virtual appliances (NVAs) like FortiGate:

Sizing is more than just picking a VM; it's about aligning your license, VM instance type, and anticipated network load.

Writing logs directly to the local virtual disk consumes valuable CPU cycles and IOPS. Offload your firewall logs to FortiAnalyzer , FortiCloud , or an Azure Log Analytics workspace via syslog to free up system resources.