v4/v6 Domain Name Conversion. This method, originally proposed in [23], is similar to the technique used to provide virtual hosting service in HTTP 1.1, which makes it possible to support multiple websites on the same web server, sharing the same IPv4 address, by exploiting the information contained in the HTTP Host header to identify the specific web site requested by the user. Similarly, it is possible to program the DNS servers in such a way that, upon a DNS request for the domain name of an IoT web service, the DNS returns the IPv4 address of an HTTP-CoAP cross proxy to be contacted to access the IoT node. Once addressed by an HTTP request, the proxy requires the resolution of the domain name contained in the HTTP Host header to the IPv6 DNS server, which replies with the IPv6 address that identifies the final IoT node involved in the request. The proxy can then forward the HTTP message to the intended IoT via CoAP.