Technical Tip: FortiClient Sticky DNS

[kumarh]

Description	This article describes that when connecting with FortiClient, the local adapter sets the DNS and when we disconnect it should change the DNS settings back to auto. However, in some cases, it does not change them back to auto. The expected behavior is client physical adapter DNS settings should be restored automatically after FortiClient disconnection.
Scope	FortiGate.
Solution	Fortinet SSL VPN Virtual Ethernet adapter gets created when Forticlient VPN is installed. If after disconnecting the VPN, the DNS IP address is still visible, perform the following steps: Try forcefully shutdown of the PC, not regular shutdown/restart (hold down Shift while clicking Shutdown in Windows 10 and 11).  Try to update the driver. Here are some articles on the web that Windows Update might cause network connection issues and might affect third-party apps as well. If Microsoft windows 10 is used and has been recently upgraded, this can cause internet-connections problems: Microsoft Confirms Windows 10 Update Can Cause Internet Connectivity Problems Mandatory Windows 10 update causing DNS and shared folder issues If the issue still persists, this is a FortiClient software issue. Try to reinstall the FortiClient software. If it still exhibits the same behavior, upgrade the FortiClient version to the latest one. It will fix the issue.