In recent versions of FortiSASE (starting from version 24.4 and later), the platform has increased its scalability to support larger enterprise environments.

Maximum Hub Support : According to the FortiSASE Mature Administration Guide and the FortiSASE 25.3.148 Feature Release Notes , administrators can now configure a maximum of 12 SPA Service Connections (SPA hubs) . Previously, this limit was restricted to 4 hubs.

Scalability for Large Enterprises : This enhancement allows organizations with complex, geographically dispersed networks—such as those with multiple regional datacenters or cloud hubs—to integrate up to 12 distinct FortiGate SD-WAN hubs into their SASE infrastructure.

Service Connection Licensing : Each SPA hub requires a dedicated FortiGate SPA Service Connection license . In MSSP environments using FortiCloud Organizations, a single FortiSASE instance can inherit these licenses from a root OU, supporting up to the same cumulative maximum of 12 service connections.

Routing and Performance : These 12 hubs form the " Private Access " backbone, where FortiSASE security PoPs act as spokes. The use of BGP (either per-overlay or on loopback) ensures that traffic is dynamically routed to the optimal hub based on the destination network and defined SLA priorities.

The core of this issue lies in the difference between Certificate Inspection and Deep SSL Inspection within the FortiSASE security framework.

The Limitation of Certificate Inspection: When " Force Certificate Inspection " is enabled in a FortiSASE firewall policy, the system only inspects the SSL handshake—specifically the SNI (Server Name Indication) and certificate headers. It does not decrypt the actual data payload of the HTTPS session.

Antivirus Scanning Requirements: To detect and block malicious files like the EICAR test file when they are downloaded over an encrypted HTTPS connection (such as https://eicar.org), the FortiSASE antivirus engine must be able to " see " inside the encrypted tunnel. This requires Deep Inspection (Full SSL Inspection), where FortiSASE acts as a " man-in-the-middle " to decrypt, scan, and then re-encrypt the traffic.

Exhibit Analysis: The Secure Internet Access policy exhibit clearly shows the toggle for Force Certificate Inspection is enabled (set to " ON " ). As specified in the Fortinet technical documentation, enabling this option forces the policy to use Certificate Inspection only, overriding any Deep Inspection settings that might be defined in the Profile Group.

Conclusion: Because the traffic is only undergoing certificate-level inspection, the antivirus engine cannot analyze the encrypted eicar.com-zip file payload, allowing the download to proceed even though an antivirus profile is active in the group.

Based on the provided exhibits, the reason why the Win7-Pro endpoint can no longer access the internet through FortiSASE is due to exceeding the total vulnerability detected threshold. This threshold is used to determine if a device is compliant with the security requirements to access the network.

Endpoint Compliance:

FortiSASE monitors endpoint compliance by assessing various security parameters, including the number of vulnerabilities detected on the device.

The compliance status is indicated by the ZTNA tags and the vulnerabilities detected.

Vulnerability Threshold:

The exhibit shows that Win7-Pro has 176 vulnerabilities detected, whereas Win10-Pro has 140 vulnerabilities.

If the endpoint exceeds a predefined vulnerability threshold, it may be restricted from accessing the network to ensure overall network security.

Impact on Network Access:

Since Win7-Pro has exceeded the vulnerability threshold, it is marked as non-compliant and subsequently loses internet access through FortiSASE.

The FortiSASE endpoint profile enforces this compliance check to prevent potentially vulnerable devices from accessing the internet.

SSL deep inspection (DPI) is a critical security function that allows FortiSASE to decrypt and inspect the actual payload of encrypted traffic (such as HTTPS, SMTPS, and FTPS) to identify and block hidden threats.

The Role of the CA: For this process to occur, FortiSASE must act as a " man-in-the-middle " by intercepting the SSL session, decrypting it for inspection, and then re-encrypting it before sending it to the endpoint. 2 To re-encrypt the traffic, FortiSASE acts as a Certificate Authority (CA) and signs a new certificate for the destination website on the fly.

Certificate Types: This CA role can be fulfilled using the default self-signed certificate provided by Fortinet (typically Fortinet_CA_SSL) or a certificate issued by an organization ' s internal/private CA . Publicly trusted third-party CAs (like DigiCert or Let ' s Encrypt) do not sell CA-capable certificates that can be used for this type of inspection.

Client Machine Requirement: Because the endpoint’s browser or operating system will not natively trust a certificate signed by a private or self-signed CA, the root CA certificate must be imported into the Trusted Root Certification Authorities store on all managed client machines. Failure to do so results in persistent certificate warnings or blocked connections for the end user.

Supported Features: Once enabled, SSL deep inspection provides the necessary visibility for high-level security features to function, including Antivirus , Web Filtering , Data Loss Prevention (DLP) , File Filter , and Application Control .