IPv6 is an Internet Layer protocol for packet-switched networks providing end-to-end datagram transmission across multiple domains. IPv6 was formally described for the first time in the Request for Comments (RFC) 2460, published in December 1998. In addition to offering a larger addressing space, IPv6 also defines some features not present in the previous version of the protocol (IPv4). For example, IPv6 simplifies the aspects of address assignment, network renumbering, and router announcements when changing network connectivity providers. Moreover, it simplifies packet processing in routers by placing the need for packet fragmentation at end points. IPv6-related patents cover issues or extensions not defined by RFCs. In this research article, we present and discuss the state of the art of such patents.