If you are currently planning a deployment, I can help you narrow down the exact instance size. Could you share a few details about your environment? What is your (in Gbps)?
Your Azure VM sizing must align with your Fortinet licensing model. Fortinet offers two primary licensing options in Azure: Bring Your Own License (BYOL)
F2s_v2 (Small), F4s_v2 (Medium), F8s_v2 (Large). 2. D-Series (General Purpose) fortigate vm sizing azure
If you license a FG-VM04 but deploy it on a Standard_F8sv2 (8 vCPUs) Azure instance, FortiOS will artificially cap its resource usage to 4 vCPUs, wasting paid Azure infrastructure. Pay-As-You-Go (PAYG / On-Demand)
| | Example Instance | Max NICs | |---|---|---| | Fsv2-series (small) | Standard_F4s_v2, Standard_F8s_v2 | 2-4 | | Fsv2-series (large) | Standard_F16s_v2, Standard_F32s_v2 | 4-8 | | F-series (older) | Standard_F8, Standard_F16 | 8 | | Fs-series | Standard_F8s, Standard_F16s | 8 | | DSv2/Dsv3 (general purpose) | Standard_DS4_v2, Standard_D8s_v3 | 4-8 | If you are currently planning a deployment, I
This architecture uses Azure Load Balancer (external and internal) to distribute traffic and detect failures using health probes. The failover time depends on the probe configuration: by default, two failed attempts measured every 5 seconds result in a maximum detection time of 15 seconds before the passive instance takes over. This design requires both FortiGate VMs to be sized to handle the full production traffic load individually.
Ideal if you need higher throughput for a lower price point and have high CPU demand but lower memory requirements. Your Azure VM sizing must align with your
FG-VMUL (Unlimited vCPU) licenses are significantly more expensive than lower tiers. Reserve FG-VMUL for environments where you need more than 32 licensed vCPUs. For most workloads, FG-VM16 or FG-VM32 provides ample capacity with lower costs.
A good rule of thumb for initial sizing is to match a FortiGate license with a similar number of vCPUs. For example, an FG-VM04 license is typically paired with a 4-vCPU instance like Standard_F4s .