Explanation
According to the VMware NSX Documentation, this VPN type must be configured before enabling a L2VPN.
L2VPN stands for Layer 2 VPN and is a feature that allows you to extend your layer 2 network across different sites using an IPSec tunnel. Route-based IPSec VPN is a VPN type that uses logical router ports to establish IPSec tunnels between sites.
https://docs.vmware.com/en/VMware-NSX/4.1/administration/GUID-86C8D6BB-F185-46DC-828C-1E1876B8