Troubleshooting Tip: How to troubleshoot VXLAN interface is disappearing after reboot problem

[seyuboglu]

Description	This article describes how to troubleshoot If the VXLAN interface is disappearing after each reboot.
Scope	FortiGate v7.4.4.
Solution	This issue is reported in the v7.4 branch. If a VXLAN's interface's underlying interface has 'set mode dhcp',  the interface disappears after each reboot.   Detailed information about VXLAN can be found in the link below. General VXLAN configuration and topologies Example configuration when the interface is created successfully:  config system vxlan     edit "VXLAN"         set interface "port1"         <----- Underlying interface.         set vni 1600         set remote-ip "10.10.10.10"     next end diagnose ip address list IP=11.11.11.11->12.12.12.12/255.255.255.0 index=5 devname=port3 IP=14.14.14.14->15.15.15.15/255.255.255.0 index=6 devname=port4 IP=169.254.40.1->169.254.40.1/255.255.255.252 index=22 devname=VXLAN diagnose sys vxlan device list vf=root name=VXLAN rip=10.10.10.10 sip=10.10.10.1 port=4898 vni=1600 flags=0x01 config system interface      edit port1                  <-----  Underlying interface.         set mode dhcp               <----- Triggering condition.     next end After rebooting the device for any reason (warm reboot, power cycle, etc.) the interface disappears.  Example output is shown below after reboot :  diagnose sys vxlan device list total device num: 0 diagnose ip address list IP=11.11.11.11->12.12.12.12/255.255.255.0 index=5 devname=port3 IP=14.14.14.14->15.15.15.15/255.255.255.0 index=6 devname=port4 The VXLAN interface will not be listed. Workaround : Re-configure the VXLAN interface a few seconds after the system reboots. As an alternative solution, EVPN VXLAN can be used. However, this involves additional configurations on routing and EVPN. Detailed information about VXLAN can be found in the link below. Using MP-BGP EVPN with VXLAN This issue will be fixed in v7.6.3 and v7.4.8.