code: func ConfigVXLANUDPPort(vxlanPort uint32) error {
  	if vxlanPort == 0 {
  		vxlanPort = defaultVXLANUDPPort
  	}
  	// IANA procedures for each range in detail
  	// The Well Known Ports, aka the System Ports, from 0-1023
  	// The Registered Ports, aka the User Ports, from 1024-49151
  	// The Dynamic Ports, aka the Private Ports, from 49152-65535
  	// So we can allow range between 1024 to 49151
  	if vxlanPort < 1024 || vxlanPort > 49151 {
  		return fmt.Errorf("VXLAN UDP port number is not in valid range (1024-49151): %d", vxlanPort)
  	}
  	mutex.Lock()
  	vxlanUDPPort = vxlanPort
  	mutex.Unlock()
  	return nil
  }
docs: // ConfigVXLANUDPPort configures the VXLAN UDP port (data path port) number.
  // If no port is set, the default (4789) is returned. Valid port numbers are
  // between 1024 and 49151.