FortiGate
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.
FortiArt
Staff
Staff
Article Id 387951
Description This article describes the effect of disabling the multiple interfaces feature on already configured firewall policies with multiple interfaces in FortiGate. In addition, it shows a CLI command for a quick check for policies configured with multiple interfaces.
Scope FortiGate.
Solution

It is assumed that the multiple interfaces feature is enabled and the firewall policies have multiple interfaces configured on them (neglecting interfaces in down status):

 

feature enabled.png

 

policy with multiple interfaces.png

 

There is a requirement to disable this feature, and there is a concern on what's the effect on the already configured firewall policies with multiple interfaces. FortiOS is smart enough that it will not break the existing configuration; however, for any newly configured firewall policy, the feature will not be available. 

 

Here, the feature is disabled; however, the screenshot shows that the multiple interfaces policy ID 1 still has multiple interfaces attached to it:

 

feature disabled.png

 

policy with multiple interfaces.png

 

policy in CLI.png

 

The following CLI command lists multiple interface policies by ID in large implementations:

 

CLI command.png

 

In summary, if the feature is disabled, it will be applicable ONLY to newly configured firewall policies, NOT the existing ones.

 

Related articles: 

Technical Tip: How to configure multiple interfaces on a firewall policy (GUI) 

Technical Tip: How to allow the configuration of policies with multiple source/destination interface...