As a novel network technology, P2P connects the clients in the network artfully and accelerates the data communication between clients. Clients could share their resources with limited network bandwidth efficiently. With the popularization of IPv6 address, more and more network clients would use IPv6 address while original P2P applications could not support IPv6 users effectively. Users with IPv4 address and users with IPv6 address could not communicate effectively. Based on a practical P2P website, this paper investigates how to extend IPv4 website to dual stack application.