3. Reliability: LSN devices potentially introduce a single point of failure in the ISP network. The Internet was designed so that traffic can take any number of paths to reach its destination, but since LSN requires all packets in a flow to take the same path through the LSN device as we discussed above, an LSN failure can isolate the ISPs customers from the IPv4 Internet. Continuing with the Golden Gate Bridge analogy, imagine if the bridge was closed for repair, or worse, collapsed.
Now you may be thinking, "These are the ISPs' problems, not mine." And you would be right. However, the ISPs' problems become your problems when the result is your Web site not being accessible to your clients and customers.
So as we can see, even though ISPs are planning on providing a mechanism for maintaining IPv4 connectivity to their IPv6 subscriber base, the effects may be undesirable. To put it bluntly, you simply can't rely on someone else (in this case, ISPs) to do the heavy lifting for you. Only you can ensure your application is accessible to your customer base, whether the customers are on IPv4 or IPv6. And the way to do that is to ensure your application is accessible via IPv4 or IPv6.
So, the world isn't going to end if you don't deploy IPv6 today, but the writing is on the wall. So, where to begin? If you haven't begun your organization's IPv6 transition, don't panic, there are plenty of resources out there to help. And here are a few pointers to help get you started.
1. First, focus on the big picture. You (or whoever the IPv6 "transition manager" will be) needs to stay out of the weeds. There are tons of small tasks that need to be done to get to IPv6, and it is easy to get sucked in. Someone needs to direct activities across the entire organization, and that person simply will not have time to be making configuration changes on routers and servers. Make sure you are seeing the forest and not getting lost in the trees.
2. Second, don't go it alone. If you will be focused on the big picture, who will do all the actual work of transitioning the organization to IPv6 (such as software upgrades, hardware upgrades, routing changes, OS changes, firewall policies, etc.). This is where the concept of "Transition Areas" comes into play. The basic idea is to break down the organization into functional groups and to spread the load around the entire organization, using slices of time from nearly everyone to do small tasks. This not only takes the burden off of a small number of individuals, but also achieves another critical goal - introducing IPv6 into the culture and getting everyone thinking about it.