Will my IPv6 setup break my access to IPv4 networks?

No. Recent operating systems are dual-stack, which mean that they are designed to talk IPv4 and IPv6 at the same time.

What can IPv6 do for me that IPv4 cannot?

• My operating system can get its IP address and default gateway without any configuration and any DHCP server.
• Thanks to the large address space, I can avoid NAT translation. This could simplify my network infrastructure, and clients could potentially benefit from lower latency.
• With IPv6 I can define specific groups of machines which will receive my multicast packets.
• IPv6 is adapted to Mobility (RFC3775).

Which applications are benefiting from IPv6-specific features?

An example is the IPv6-based earthquake alert system in Japan. Alerts are sent to a multicast group of machines, with a low latency.

Is IPv6 difficult to use and configure?

IPv6 is already enabled in all recent operating systems. Moreover you may want to benefit from the auto-configuration. Or, if you want a specific configuration (DHCPv6-based for example) the set up will be similar to the one you would need for IPv4.

How is evolving the IPv4 pool?

A drawing is better than a long talk: