Troubleshooting Tip: Internal interface native VLAN changes after switch reboot

[sachitdas_FTNT]

Description	This article describes how to consider if FortiSwitch's internal interface native VLAN changes to a different VLAN after the switch reboot
Scope	FortiSwitch v7.2.x and above.
Solution	Starting from FortiSwitch v7.2.0, the 'auto-network' feature has been introduced. Refer to the link: Special notices By default, this is enabled for FortiSwitch to come up in FortiLink mode and the mgmt-vlan is set to 4094: config switch So, after a FortiSwitch reboot, the switch's internal interface native VLAN is changed to 4094. Command: show full-config switch interface internal If the FortiSwitch runs in standalone mode, it is possible to disable this feature. config switch auto-network     set status disable end Disable the FortiLink auto-discovery on the FortiSwitch        config switch global        set fortilink-auto-discovery disable  <----- If the FortiSwich is used in 'Fortilink over layer3' mode and if a different native VLAN needs to be configured on the internal interface, then change the mgmt-vlan. For example: On FortiSwitch: config switch auto-network     set mgmt-vlan 1     set status enable end On FortiGate: config system interface     edit <fortilink interface name>         set switch-controller-mgmt-vlan 1     end Related article: Technical Tip: FortiLink mode over a layer-3 network