As we start to plan for IPv6 and start to deploy it on our networks we should try to anticipate the operational costs related to running both IPv6 and IPv4. IPv6 provides more addresses and some minor opportunities for cost savings. IPv4 addresses are becoming scarce and IPv4 networks are becoming increasingly costly to maintain. The combination of these operating costs and the long-tail of IPv4 will burden most organizations.
Transitioning to IPv6 is an inevitability because we will not be able to sustain the current level of Internet growth solely with IPv4. Eventually, all Internet systems will need to embrace IPv6. When planning for IPv6 deployment it is customary to review the plentiful transition techniques. Of all the IPv6 transition techniques, the dual-protocol approach is the most feasible. Even though tunnels and translation are options, it is far better to "go native" when it comes to IPv6. Even though the industry is looking for ways to prolong the lifespan of IPv4, the transition to IPv6 will necessitate running IPv4 in parallel with IPv6 for many years. The fact is that we do not anticipate decommissioning IPv4 anytime in the next 10 years.
Increasing scarcity of IPv4 addresses requires network administrators, system administrators, security administrators to spend their time on address reclamation activities. These IT administrators will have their plates full with identifying blocks of public IPv4 addresses and removing those addresses from internal systems and changing them to private IPv4 blocks. These public IPv4 addresses on the internal networks will need to be replaced with private IPv4 addresses, and those public IPv4 addresses used for public Internet-facing applications. Public IPv4 addresses will also be needed for public NAT/PAT pools due to the increased load on NAT systems. Today, many large organizations that use private IPv4 addresses internally will need to groom their private IPv4 address space to endure the long-term use of IPv4 while IPv6 adoption becomes ubiquitous.
IPv6-related capital expenditures (CAPEX) will not be substantial because much of an organization's IT systems are already IPv6 capable. Many computer operating systems, routers, and firewalls are now IPv6 capable by default. However, there are many organizations that are still using older operating systems like Windows XP. Windows XP does not come with IPv6-enabled by default, but although it can be manually enabled, it does not include a DHCPv6 client and it only performs DNS queries over IPv4 transport. Organizations will want to upgrade to at least Windows 7 before deploying IPv6 on their internal networks. Besides the licensing cost for the new operating system, upgrading to Windows 7 will likely require upgrading computer hardware to support the increased memory, CPU, and storage requirements. Similar upgrades may be required for other operating system brands and versions. This upgrade may require significant CAPEX, but it might be required regardless of the eminent IPv6 migration.
If a company has old systems that do not support IPv4, they will need to be upgraded to support IPv6 at some point, but their function may determine when that capital expenditure is required. It may be acceptable if the computer room UPS does not support IPv6 over its management interface. However, if the perimeter firewall does not support IPv6 then you will likely need to purchase a new one. The perimeter firewall is one device that is on the critical path of your IPv6 deployment project plan, and that capital expenditure will likely occur sooner rather than later.
Some organizations have been planning to reduce the cost to migrate to IPv6 by simply upgrading IT systems on an multi-year lifecycle basis. The assumption is that if they start to procure new IPv6-capable systems on a 6 to 8 year cycle, eventually everything in their infrastructure will be IPv6-ready. However, many organizations have not held fast to these procurement guidelines and have perpetuated purchasing IPv4-only systems. These organizations have also created IPv6 upgrade cost models by only considering the cost of hardware or software licenses, but not considering the investment of people's time to migrate to IPv6. The hardware and software upgrade costs are just the tip of the iceberg compared to the amount of human effort required to migrate to IPv6.
Organizations must consider the operating expenses (OPEX) related to the transition to IPv6 and the long-term operation of IPv6. Initially, the significant cost related to IPv6 is the training that IT staff will need to become proficient with IPv6. Few people in organization's IT staff have invested their own time to learn about IPv6 and virtually all IT staff will need to become knowledgeable about the new protocol, addressing and troubleshooting. After these people are trained, then they will be working to apply IPv6 configurations to routers, firewalls, DNS, computers, applications, and many other systems. This level of effort will be significant and occur in addition to their normal IPv4-related responsibilities.