What Does Dual Stack Network Mean?
A dual stack network is a network in which all of the nodes are both IPv4 and IPv6 enabled. This is especially important at the router, as the router is typically the first node on a given network to receive traffic from outside of the network.
Many experts believe that network infrastructure will shift from IPv4 to IPv6 in order to provide more adress space and serve growing global connecitivity. Dual stack networks are one of the many IPv4 to IPv6 migration strategies that have been presented in recent years.
Techopedia Explains Dual Stack Network
A dual stack network involves nodes that are capable of processing IPv4 and IPv6 traffic simultaneously. When a node within a dual stack network receives traffic, it is programmed to prefer IPv6 over IPv4 traffic. In the event that the traffic it receives is solely IPv4, then the dual stack node is capable of processing it as well.
Dual stack networking is one of several solutions for migrating from IPv4 to IPv6, but it is also one of the most expensive.