This is a known issue affecting VMware NSX for vSphere 6.2.x, 6.3.x and 6.4.x.
Currently, there is no resolution.
Note: Your physical hardware switch may not have support for nested VXLAN with both the inner and outer VXLAN encapsulation using the same port (4789).
Workaround:
To work around this issue, change the VXLAN port either in NSX or in the physical switches so that they are both not using port 4789.
Note: Starting with NSX 6.2.3, the default VXLAN port is 4789, the standard port assigned by IANA. Before NSX 6.2.3, the default VXLAN UDP port number was 8472.
For more information on instructions to change the port in NSX-v to port 8472, see the
Change VXLAN Port section of the
NSX Upgrade Guide. If you are using Cross-vCenter NSX, see the Change VXLAN Port in
Cross-vCenter NSX section of the
NSX Upgrade Guide.