Is it possible to simultaneously have an IPv4 and an IPv6 address?
Yes. Most of the operating systems currently supporting IPv6 also support IPv4, hence allowing for the simultaneous use of the two protocols. In this way, it is possible to communicate with both IPv4 and IPv6 networks instead of being restricted to one type of network only. In addition, the support of both protocols will permit the use of applications that are specifically designed to work with only one of the two protocols.