During the transition from IPv4 to IPv6, the IPv6 islands inside the IPv4 networks need to communicate with each other and with the native IPv6 network. The drawback of existing IPv6 transition methods is that relay gateways become potential communication bottlenecks. In this paper, a new method-PS64-is presented to connect IPv6 islands together over IPv4 network and reduce the reliance on these relays by shifting the burden to edge gateways on each island. In this method, direct tunnels are set up between the IPv6 islands, and a P2P network is maintained between edge gateways of these islands to propagate information of tunnel end points. After describing the algorithm, we analyze the connectivity of the P2P network, the scalability of this algorithm, and present the prototype and experiments. The results of our analysis and experiments show that the proposed method is reliable, scalable and effective. Obviously, this technique works for all IPvX over IPvY situations.