New possibilities offered by IPv6

The new Internet protocol version 6 (IPv6) has many simplifications and new features compared to the older Internet protocol version 4 (IPv4). The new header is very simple. A fixed format is assigned to all headers. Some new fields were added to the header. Flow ID indicates that the packet belongs to a certain flow. A flow is identified by the source address, destination address, and the flow ID. It is possible to set up a cached flow-handling state as the first packet of the flow is processed on network layer (layer 3). The following packets are forwarded based on the information in cache. This makes an enormous saving of time in layer 3 processing delay. The transitioning to IPv6 requires dual stacks at routers, i.e. the ability to handle both IPv6 and IPv4. IPv6 islands can be connected to one another through IPv4 tunneling