“IPV what?” 

Phil Benchoff, then a network engineer, recalls the day in 1997 when Jeff Crowder, then program director for Network Virginia, came into his office and said, “Erv wants us to support ECE in their IPv6 research. He says it will be important.” 

Erv Blythe, then vice president for information technology and now vice president emeritus, was right. Today, IPv6 is keeping the internet from running out of address space. As one of the earliest adopters of IPv6, Virginia Tech has played a pioneering role in shaping how networks can be configured to keep up with an expanding internet.

“Two enthusiastic Ph.D. students in electrical and computer engineering were ready to deploy a prototype network using this new protocol called ‘IPv6,’” said Scott Midkiff, then a  faculty member in the Department of Electrical and Computer Engineering (ECE). “I knew we needed the help of the university’s network team to make this happen. Erv Blythe was always supportive of researchers and new ideas, so he volunteered the team to help with this project.”

Midkiff now serves as vice president for information technology and chief information officer for Virginia Tech.

Why does IPv6 matter?

No one is in charge of the internet. It works because those who build and run the networks, devices, and servers we all depend on have mutually agreed to use an Internet Protocol, or IP, standard. Every device, server, or domain that connects to the internet gets assigned a unique IP address, which is used to determine where information is sent and received.

Internet Protocols have been codified by the Internet Engineering Task Force, a loosely organized international body where proposed innovations can be tested and considered before being adopted. This process has been vital in creating and upholding an open internet.

The first widely adopted Internet Protocol — version four, commonly known as IPv4 — uses a 32-bit, numerical address structure providing for a maximum of 4.3 billion IP addresses. With nearly 8 billion people — and all their devices, including an estimated 6.92 billion smartphones alone — on the planet today, the limitations of IPv4 are rather apparent. IPv4 simply does not provide enough addresses to meet the world’s needs.

Network providers and device manufacturers have devised a number of workarounds to artificially expand the number of devices that can connect through a single public IPv4 address. However, these workarounds are not optimal and have the potential to compromise the free and open nature of the internet. For example, those who hold public IP addresses could potentially charge customers high fees to connect. 

IPv6 was designed to address the addressing problem while allowing for innovation as the internet continues to grow and evolve. Each IPv6 address is 128 bits long, which provides roughly 3.4 x 1038 unique IP address possibilities, offering room for network scaling that was not possible with IPv4.

According to Eric Brown, senior network architect in Virginia Tech's Network Infrastructure and Services, the internet is far from complete.

“As new technologies are developed, the internet will need to adapt. IPv6, with the much longer address structure, removes constraints on what we can do with it, and leaves the design space open to future engineers to build capabilities we have yet to even imagine.” said Brown.

Eric Landgraf, a network engineer who joined the team in 2016, said, “With IPv6, we have the flexibility to scale our network as needed, and we can encode additional information such as building details or customer ID into a network address.”

IPv4 address example The Network ID contains network information and could include the first one to three sets of numbers. The Host ID or rest field contains device information and uses the remaining number sets. IPv6 address example 2001:db8:26:012a:8008:6c9a:ffbd:b011. The Network ID, first half of address, includes global routing prefix, subnet ID, and other network information. The Interface ID, second half of address, includes information about the connected device and has room to add more information as needed.
IPv6 has a much longer and more flexible address structure compared to IPv4.

Becoming one of the earliest adopters of IPv6

The first specifications for IPv6 were presented in 1995, and it has taken decades for most network providers to begin implementing it. In contrast, Virginia Tech was a very early adopter.

“Like most things at Virginia Tech, it started out as a research project,” said Benchoff, who is now a senior escalation engineer with Network Infrastructure and Services.

An ECE research team that included Ph.D. candidates David Lee and Dan Lough and faculty members Nat Davis and Midkiff, were experimenting with IPv6. Blythe asked Benchoff to collaborate with the research team so that they could expand testing of the new protocol to include the university’s network infrastructure. 

“My first actions were to enable IPv6 on my desktop and create a virtual link to the router ECE was running,” Benchoff said. “We spent nearly a year finding things we could patch to support IPv6, setting up domain name service, figuring out how to do a broader deployment in a reasonably safe manner, and enlisting interested members of the campus community to test our progress.”

Lee, who now works as a consultant in San Jose, California, said, "As a Ph.D. student, I wanted the biggest field of possibility I could get for the experiments I needed to do. Sometimes student projects can sort of trample over things on the operational side, but I had made some good connections with the folks in [NI&S], and we took the approach of doing this in a cooperative way that worked really well."

Earving Blythe stands in front of large antenna.
Earving "Erv" Blythe pictured in the 1992-93 President’s Report, on the eve of the Blacksburg Electronic Village project that made Blacksburg the “most wired community” in the mid-1990s and just a few years before Virginia Tech first deployed IPv6.

On Jan. 30, 1998, the university launched the first production IPv6 network on the Virginia Tech campus. From that point forward, Virginia Tech users who wanted to communicate over IPv6 could do so with a small but expanding community of IPv6 users in the U.S. and abroad.

“We did it in the safest way possible,” said Brown. “We didn't run IPv6 on the same systems that ran the rest of the network — we set it up on a kind of parallel system.” That way, if something went wrong, the network engineering team could work on the issue without disrupting the primary network. That parallel network ran for about 10 years while a team including Brown; Benchoff; Brian Jones, who is now the director of operations for NI&S; and Carl Harris, Virginia Tech’s chief technology architect, worked gradually to enable IPv6 throughout campus networks.

Reaching full implementation over a decade ahead

To most of us, IT service upgrades seem to happen with the flip of a switch. We never see the years of hard work behind the scenes that make the magic happen. Implementing IPv6 has been no exception. 

“IPv6 has to be configured on the network you're on, and that network has to be configured to talk to other networks. After that, you start modifying the devices on the network to be IPv6-enabled, and then the service on the other end needs to be both IPv6-enabled and have the ability to tell other hosts how to map the service, such as 'https://www.google.com,' to an IPv6 address,” said Landgraf.

Because so few institutions outside of Virginia Tech were equipped to support IPv6 during the early years, the university's network engineers configured "tunnels" on certain servers to allow IPv6 data packets to flow between the sending and receiving networks. As testing progressed, they gradually built a "backbone" of IPv6-enabled routers that connected various campus buildings with the university's internet service provider so that Virginia Tech networks could communicate outside the university. 

By 2008, Virginia Tech was ready to fully emerge from the testing phase. In rapid succession, Virginia Tech enabled the protocol in academic buildings and residence halls and moved off the parallel network. In 2009, the university became one of the first places where users could reach Google over IPv6. By 2010, Virginia Tech was ranked by Google as one of the top five deployments worldwide, based both on percentage of IPv6-enabled hosts and traffic volume. In 2011, the university was asked to consult with the United States Federal IPv6 Task Force to offer advice about transitioning to IPv6, and presented at the 2011 IPv6 World Congress in London.

On June 6, 2012, the university was a leading participant in World IPv6 Launch Day, a global event during which 400-plus entities permanently enabled IPv6 on their networks. Virginia Tech emerged at the top of the network operator category, with nearly 60 percent of its network hosts supporting IPv6.

Since World IPv6 Launch Day, Virginia Tech’s IPv6 deployment has steadily grown to almost 90 percent of the network compared to about 30 to 40 percent worldwide.

group photo in an office
(From left) Mark Gardner, Carl Harris, Phil Benchoff, Richard Jimmerson, and Eric Brown. Jimmerson visited Virginia Tech in 2013 as a representative of the Internet Society to discuss follow-up activities to the World IPv6 Day events that took place in the years prior. Jimmerson is now with the American Registry for Internet Numbers. Photo courtesy of Richard Jimmerson.

Shaping the internet's future

Worldwide deployment has lagged because of a reluctance on the part of network administrators to invest the time and money needed to remap all their services and addresses, even knowing that we’ve already reached the end of IPv4 addresses

However, investing in IPv6 from virtually the beginning has paid off for Virginia Tech, not only in terms of recognition, but also in the university's capacity to support research and its readiness for the future. The university is in a better position than many of its peers to support the needs of students, researchers, and industry partners. “We’ve gotten pretty good at operating an IPv6 network and know quite a bit about how systems can be brought on the network safely and reliably,” said Brown.

The university’s robust IPv6 connectivity has poised Virginia Tech to be more competitive in research. Cutting edge communications technologies such as 5G and 6G rely heavily on IPv6 from an engineering perspective because of the sheer number of devices that need to connect to these networks without delay. “IPv6 is indispensable to modern research practices,” said Calvin Winkowski, research associate with the Virginia Tech Transportation Institute. “With IPv6 and Internet2, our institute has collaborated with other universities and companies to collect and house petabytes of data, including over 1,000 years of video. Transportation safety has been improved by our research, which was built on IPv6 in a way that would not be possible with obstacles from legacy IPv4.” 

By engaging with peers in the network engineering community from the early days, said Landgraf, “we have shaped both vendor products and best practices. We certainly had our share of trial and error, but we stayed focused on figuring out solutions, instead of viewing problems we encountered as an excuse to avoid change.”

Richard Jimmerson, chief operating officer for the American Registry for Internet Numbers, is one of those peers. He said, "Virginia Tech has been a long-standing proof positive example of IPv6 deployment. To boost the confidence of other organizations who are wanting to move forward with their own IPv6 deployments, Virginia Tech has been one of the most frequently-cited successful use cases. Thank you to Virginia Tech for clearing the way for so many others."

As the internet continues to evolve, Benchoff stresses the importance of preserving an open internet where innovators don't need “permission or access from someone else to build new resources, share information, or provide novel services. What we want is to provide an environment where an internet connection and some ingenuity is all that is needed to enable that creativity.”

The time that Virginia Tech has spent on creating this type of environment over the past 25 years, and sharing lessons learned with the larger technology community, has made it easier for commercial internet service providers to enable IPv6 connectivity for their users. Benchoff said, “This is exactly what land-grant universities were created to do — to innovate and share knowledge for the sake of the greater good.”