By: Jeff Patterson on August 6th, 2018

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IPv4 To IPv6 Migration: Why the wait?

Data Center | Cybersecurity | Data Center Networking

Have you transitioned your company’s network away from IPv4 and over to IPv6 yet? If not, why? For years now, we’ve heard apocalypse-type theories of how we need to move to IPv6 or the internet will die. IPv4 exhaustion has been rumored since the 1990s and IPv6 has been around for 19 years, so if you haven’t made the jump, you’re not alone. Google tracks IPv6 statistics and, as of December 2017, only 18.67% of the world has deployed IPv6, with the United States adopting at a faster approximate 25% rate. If we all know that IPv6 will be the standard at some point, then why is it taking so long to transition?


One of the main factors is that changing the Internet Protocol (IP) can’t be done one connection at a time. A sending system that creates an IPv6 packet needs all the routers, firewalls, and load balancers that are in its path to understand and be able to process the IPv6 packet. Plus, the receiving system needs to able to understand the IP packet for everything to work correctly. We can’t just upgrade a server and a client application; it also requires upgrading everything in between.


Another driving factor is that we still haven’t run out of IPv4 addresses. The Internet Assigned Number Authority (IANA) is responsible for the global coordination of all IP addresses, which they in turn allocated to the five Regional Internal Registries (RIR). The IANA exhausted its IPv4 address pool in February 2011 when they allocated the last five /8 address blocks, one to each of the five RIRs. Only AFRINIC still has available IPv4 addresses, although they estimate it will also run out sometime in 2018. These two facts sure make it sound like we’ve run out of IPv4 addresses and are in big trouble, right? Not to worry, the Internet Service Providers (ISP) still have IPv4 addresses that can be assigned to customers.


The main reason we haven’t run out of IPv4 addresses is the use of Network Address Translation (NAT), the method of remapping one IP address space into another. Most of NATs map private hosts to one publicly exposed IP address, which reduces the public IPV4 addresses required. ISPs take this one step further with the use of carrier grade NAT. This allows them to use private address space within their network and perform the mapping to a public address at the demarcation point to the Internet. The use of Classless Inter-Domain Routing (CIDR) and ISPs pulling back unused address space from customers has also helped preserve IPv4 addresses.


Although the exhaustion of IPv4 has taken longer than expected, it will happen. The prolific use of mobile devices and the Internet of Things (IoT) will only speed that process up. Don’t wait! Get started on the process and be prepared to the make the change. Here’s how:

  1. Start evaluating the devices on your network to determine which ones are IPv6 capable and which ones need to be upgraded.
  2. Obtain an IPv6 prefix and develop an addressing plan.
  3. Discuss migration options and document transition methods. Microsoft has been enabling IPv6 on Windows as the default for years now, so chances are you already have IPv6 traffic on your network.


Need help with a plan for migrating your IPv4 to IPv6, or just have questions? Reach out to our Intelligent Infrastructure team. Our engineers are highly experienced to assist with developing and executing a transition plan that’s tailored to your unique environment and capabilities. Set your business up for IPv6 success today!




About the Author

Jeff Patterson has worked in technology for over 20 years and has experience working with enterprise networks, security, collaboration, and mobility.  He currently holds a CCIE in route switch and a CCDE.  Jeff is a Solutions Consultant with Internetwork Engineering where he works with clients to design solutions that support both their business and technical needs.