In this article we will describe a commercial service that will use distributed resources, such as storage or bandwidth, in a cooperative effort. We name this service "durable storage". This service is able to guarantee the existence of the data it contains in "any circumstance" at "any time". Although the solution is based on a P2P paradigm, we use a centralized approach that matches the commercial side of the service. We have designed the system with anonymity, confidentiality and security in mind. The ISP, or service provider, will not only assure several of the main functions, such as authentication or directory maintenance, but constitutes as well the only billing point for every user. We will describe the architecture or the service and the implementation of the prototype which is a dual stack IPv4/IPv6 application. Finally we will point out that the solution is not only IPv6 compatible, but it could clearly benefit from an IPv6 only version.