Comparison
Now that you know the available techniques, I’ll summarize them by listing advantages and disadvantages. This summary should help you determine which way to go.
Dual Stack
This technique is easy to use and flexible. Hosts can communicate with IPv4 hosts using IPv4 or communicate with IPv6 hosts using IPv6. As soon as everything has been upgraded to IPv6, the IPv4 stack can simply be disabled or removed. Disadvantages of this technique include the following: you have two separate protocol stacks running, so you need additional CPU power and memory on the host. All the tables are kept twice, one per protocol stack. Also, you need to deal with different commands for each protocol because each command has a different set of command-line options. A DNS resolver running on a dual-stack host must be capable of resolving both IPv4 and IPv6 address types. Generally, all applications running on the dual-stack host must be capable of determining whether this host is communicating with an IPv4 or IPv6 peer. If you are using dual-stack techniques, make sure that you have firewalls in place that protect not only your IPv4 network, but also your IPv6 network.
Tunneling
Tunneling allows you to migrate to IPv6 just the way you want to. There is no specific upgrade order that needs to be followed. You can even upgrade single hosts or single subnets within your corporate network and connect separated IPv6 clouds through tunnels. You don’t need your ISP to support IPv6 in order to access ...