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.
SAJUDIYA
Staff
Staff
Article Id 354252
Description

This article describes that FortiGate does not detect any ISL or ICL the command 'diagnose switch-controller switch-recommendations fabric-lockdown-disablereturns successful but the option remains enabled.

 

That is expected behavior when there is only one FortiLink interface because Locking down ISLs and ICLs is one of the recommendations in the Security Rating report (Security Fabric -> Security Rating).


However, if there is more than one FortiSwitch and at least one ISL or ICL, then it should be able to disable that option (either from GUI or CLI).

Scope FortiSwitch, FortiOS.
Solution

To disable Lockdown ISL, need to have more than one FortiLink, it can disable ISL from GUI as below:

 

LockdownISL.png

 

To disable from CLI, run the below command:

 

diagnose switch-controller switch-recommendation fabric-lockdown-disable

 

Note: From FortiOS 7.0.2 and above:

Add commands to lock down ISL/ICL links between FortiSwitches so that they become static configurations:

 

diagnose switch-controller switch-recommendation fabric-lockdown-check

diagnose switch-controller switch-recommendation fabric-lockdown-disable

diagnose switch-controller switch-recommendation fabric-lockdown-enable

 

This adds stability during events such as cable disconnection or power outages.

 

Note: The issue is now resolved on the new FortiGate v7.4.8 GA and v7.6.3 GA and higher versions:

 

1015992 - WiFi & Switch Controller -> FortiLink Interface: When a FortiLink interface is down and the 'Lockdown ISL' toggle is set to 'disable' on the GUI, the setting is not retained.

FortiOS 7.4.8 resolved issues.

FortiOS 7.6.3 resolved issues.

 

Related documents: