Created on
03-05-2025
09:51 PM
Edited on
10-27-2025
08:08 AM
By
Jean-Philippe_P
This article discusses the 'Single FortiGuard license for FortiGate A-P HA cluster' feature detailed in the FortiOS Administration Guide, with the aim being to demystifying when the feature can be used and what it affects from a licensing perspective.
FortiGate v7.2.9, v7.4.6, v7.6.1 and above.
Traditionally, FortiGate HA clusters have required each cluster member to be individually licensed for a given set of features.
If those HA members have differences in their licensing, then the cluster will negotiate down to the lowest common denominator (for example, if one FortiGate has FortiGuard Web Filtering service and the other does not, then the cluster as a whole will not be able to use FortiGuard-based Web Filtering features).
The new 'Single FortiGuard license for FortiGate A-P HA cluster' feature (supported in v7.2.9, v7.4.6, v7.6,.1, and later) allows administrators to purchase HA-specific FortiGate SKUs that can be registered to FortiCare and associated with a Virtual Serial Number (vSN).
This vSN can then have a singular license applied to it, which is then usable for both members of the HA cluster (as opposed to needing licensing for each FortiGate individually). For reference, check out the following documentation on the Fortinet Docs Library:
There are some key caveats to this new feature that administrators should take into consideration. This is covered in the section below.
Caveats and Other Considerations:
This feature is only supported for new HA-specific FortiGate SKUs (and only for a specific selection of FortiGate models at this time). Notably, this means that it is not possible to enable this vSN/single license HA feature for existing HA clusters made up of standard FortiGates (i.e., this feature is only supported for new deployments and HA SKU FortiGates only).
For example, to utilize this feature, an administrator would need to purchase a pair of HA-SKU FortiGates (such as 2x of the FG-40F-HA SKU for the FortiGate-40F), register them to FortiCare, and then follow the setup steps as detailed in the Administration Guide (see links above). In particular, the enabling of the logical-sn option under 'config system ha' will result in the FortiGates registering and receiving a Virtual SN, after which the single set of licenses can be registered to the vSN in FortiCare.
Example of the ordering process for a 40F HA:
Ordering Process:
2x FortiGate-40F-HA.
1x FC-10-0040F-809-02-DD (Enterprise).
Important Note:
The logical-sn option does technically appear in the CLI for non-HA FortiGate SKUs, but it will not work when enabled (FortiCare/FortiGuard will not register a vSN for non-HA SKU FortiGates, so the feature cannot be used for existing FortiGates).
Some features are not yet available for devices that have Virtual SN enabled.
Features requiring individual device subscription:
Features are not currently supported for devices in a logical-sn cluster:
The vSN/single license HA feature only supports Active-Passive HA cluster configurations (no Active-Active support), and it also only supports clusters with two members. Changing a vSN-based cluster from Active-Passive to Active-Active will result in the FortiGate cluster losing its vSN, which in turn will result in service entitlements no longer being applied to the cluster members.
This could cause impacts on user traffic, depending on the security profiles being utilized (for example, Web and DNS Filtering in particular may be disrupted due to FortiGuard rating errors).
Note:
There is a known issue with ID 1137565 for 10xF models where the logical-sn command is missing and is fixed in v7.4.8, v7.6.3, as well as with upcoming v7.2.12. Refer to the release notes for further information.
The serial number for vSN should appear in the Product list on the support portal, with the prefix FGxxxFHAyyyyyyy, where 'x' stands for the type of unit and 'y' is part of the serial number.
Related articles:
Technical Tip: The HA Cluster requirements
Technical Tip: FortiGate Models and FortiOS support for HA Licenses
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