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akomurlu
Staff
Staff
Nov 24, 2025 10:21 AM UTC

Troubleshooting Tip: Using loopback Interface for LocalOut

Description This article describes the issue of using a loopback interface as the source interface for LocalOut in FortiGate, and provides a step-by-step solution to resolve the problem. The article explains how to configure an alternative interface as the source for DNS and FortiGuard services.
Scope FortiGate.
Solution

To resolve the issue of using a loopback interface as the source interface for LocalOut in FortiGate, follow these steps:

  1. Go to Network -> Interface and create a new interface or use an existing one that is not connected to any network.
  2. Configure the new interface with the public IP address that was previously assigned to the loopback interface.
  3. Go to System -> FortiGuard and set the source IP address to the IP address of the new interface.
  4. Verify that the FortiGate can reach the FortiGuard servers using the new interface.

 

From CLI Console:

 

config system fortiguard
    set source-ip xx.xx.xx.xx    <- Replace xx.xx.xx.xx with the loopback IP.
end

 

By following these steps, configure an alternative interface as the source for DNS and FortiGuard services, resolving the issue of using a loopback interface as the source interface for LocalOut.

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