The main task of the VTEP controller is to allocate IPs to nodes.

Adequate validation and status reporting should be considered.

A managed VTEP subnet cannot conflict with existing IPs on the nodes.
An unmanaged VTEP could validate that all nodes are allocated with the appropriate IPs from the subnet.

Consider allocating an ID per VTEP that we can use across all the node to identify related interfaces.

A finalizer needs to be implemented so that a VTEP cannot be deleted while in use by a CUDN.