IT execs know they will have to deploy IPv6 at some point, but where to begin? One approach that establishes some IPv6 capability without spending a lot of time or money is to start at the perimeter.
IPv6-enabling routers, firewalls and DNS servers should be straightforward. If an organization were to deploy an IPv6-capable Server Load Balancer (SLB) or, using the most current term, Application Delivery Controller (ADC), they could configure an IPv6 Virtual IP (VIP) and an IPv4-only server farm.
This would allow Web apps hosted on IPv4-only servers to appear to the Internet user as IPv6-applications. The way it works is that clients would connect to the IPv6 VIP, and the ADC would perform a reverse-proxy function and terminate the IPv6 HTTP Internet connection, then create a new IPv4 HTTP back-end connection to the IPv4-only application servers. The server would not necessarily know the IP version being used by the client and it would happily return the data to the ADC appliance using IPv4. The ADC appliance takes that IPv4 response from the server, copies the HTTP application data and transmits it back to the IPv6-connected client.