FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
This article describes an issue where a valid local certificate does not appear as an option when configuring a Virtual Server on FortiGate.
Scope
FortiGate.
Solution
For a local certificate to be selectable under Policy & Objects -> Virtual Servers, the certificate must include the TLS Web Server Authentication value under the Extended Key Usage field.
To verify:
Go to System -> Certificates.
Select the certificate and review the details.
Ensure that the Extended Key Usage includes: TLS Web Server Authentication.
If this value is missing, FortiGate will not recognize the certificate as valid for Virtual Server usage.
Resolution: Request a new certificate from the Certificate Authority (CA), ensuring that the CSR (Certificate Signing Request) includes the correct Extended Key Usage extension.
