Twenty-five years ago Saturday, on August 3, 1999, IPv6 history was made: ESnet was issued its IPv6 production netblock, which is still in use today.  The American Registry for Internet Numbers (ARIN) assigned the very first block out of its 2001:400::/23 allocation, and since then, ESnet has numbered its production IPv6 services out of 2001:400::/32.  (The netblock would have originally been a /35, later increased to /32 automatically by the RIRs.)  

This was the first production IPv6 address allocation in North America, and possibly the world.  Akira Kato, a global Internet pioneer, member of the WIDE Project, and a professor at Keio University, notes that the WIDE project did receive the first allocation in the Asia-Pacific region 8 days after the allocation of ESnet’s space.  WIDE, along with its sub-project, KAME, would go on to develop critical IPv6 software, some of which is still in use today.  (WIDE continues to have the numerically-lowest globally routable production IPv6 address, 2001:200::/32.)

IPv6 is the current generation Internet Protocol, and it has been in an extended process of supplanting the now-legacy IPv4.  Developed in the early 1990s, it was adopted by ESnet as part of a larger effort to lead by example–by embracing cutting-edge protocols and technologies.  IPv6’s massive address space was originally seen as a way of effectively “saving the Internet” from potential collapse due to the exhaustion of IPv4’s more limited address space.  While mechanisms such as network address translation (NAT) were developed to extend IPv4’s life, ESnet quickly recognized the drawbacks that these mechanisms created, especially in the high-performance computing and networking environments ESnet supported.  Hence, the move to IPv6 was an obvious one for ESnet, and the organization encouraged other National Labs to follow suit.

Before Production

ESnet’s involvement in IPv6 predates our effective move to production by at least three years.  As we noted in 2021:

Bob Fink, Tony Hain, and Becca Nitzan [all ESnet staff at the time, circa 1996] spearheaded early IPv6 adoption processes, and their efforts reached far beyond ESnet and the Department of Energy (DOE).  The trio were instrumental in establishing a set of operational practices and testbeds under the auspices of the Internet Engineering Task Force–the body where IPv6 was standardized–and this led to the development of a worldwide collaboration known as the 6bone.  6bone was a set of tunnels that allowed IPv6 “islands” to be connected, forming a global overlay network.  More importantly, it was a collaboration that brought together commercial and research networks, vendors, and scientists, all with the goal of creating a robust internet protocol for the future.

In addition to 6bone, ESnet was one of three principals that created and managed 6tap, one of the first IPv6 internet exchanges.  Collocated at the Starlight research and education network exchange in Chicago, 6tap represented a collaboration between ESnet and Canadian partners CANARIE and Viagenie.

Moving to Native IPv6

With experience gained in the 6bone and 6tap projects, ESnet staff, with other partners in the Internet, began to advance the cause of the creation of a production IPv6 network.  The goal would ultimately be a native IPv6 network–no overlays, no tunnels.  This would require new blocks of address space to be delegated to the still-nascent Regional Internet Registries (at the time, ARIN in the Americas, APNIC in Asia-Pacific, and RIPE-NCC in Europe and the Middle East/Africa).  Those RIRs would need policies and procedures for allocating IPv6 address space.  But first, they needed to get their own blocks from the Internet Assigned Numbers Authority (IANA).  After nearly two years of deliberation (and much input from ESnet staff to bodies like the IETF and RIRs), IANA made the assignments on July 14, 1999:

After much discussion concerning the policy guidelines for the deployment of IPv6 addresses, in addition to the years of technical development done throughout the Internet community, the IANA has delegated the initial IPv6 address space to the regional registries in order to begin immediate worldwide deployment of IPv6 addresses.

We would like to thank the current Regional Internet Registries (RIR) for their invaluable work in the construction of the policy guidelines, which seem to have general consensus from the Internet community. We would also like to thank the efforts of the IETF community and the support of the IAB in making this effort a reality.

The stage was now set for ESnet to receive the first public production IPv6 addresses, and help usher in a new era for the Internet.  Thus, while Tony Hain and Bob Fink were busy chairing IETF working groups and writing RFCs, Becca Nitzan began building a production IPv6 network within ESnet.  Nitzan configured her DEC Alpha workstation, hershey.es.net, to be dual stack–possibly the first workstation in North America, if not the world, to be on a production IPv6 network.

ESnet continues to maintain hershey’s historic EUI64-based IPv6 AAAA entry in the public es.net domain.

2008 – Present: New Generation(s) Take Over

Eventually, Hain, Fink, and Nitzan all moved on from ESnet, either into the private sector or retirement, but a new generation took over to continue IPv6 development in the Department of Energy’s research network:

• Kevin Oberman carried the torch of IPv6 evangelist in ESnet, promoting the protocol and educating DoE sites about the virtues of the new technology.
• Michael O’Connor developed the first tools for network monitoring and topology discovery in ESnet–and made them exclusively run over IPv6.
• When it came time for Oberman to retire, Michael Sinatra transferred from UC Berkeley to ESnet to become IPv6 and DNS subject matter expert.  He proceeded to unite IPv6 and IPv4 routing under a single interior routing protocol, developed tools to manage the IPv6 side of ESnet’s rich peering infrastructure, continued educating research and education and government networks on the risks of not adopting IPv6, and is currently involved in building a segment-routed network capable of carrying both IPv4 and IPv6 traffic while only using IPv6–eliminating IPv4–for the control plane.
• Nick Buraglio joined ESnet in 2013 and has continued in the tradition of Hain and Fink, spearheading DoE and other US Government agency adoption of IPv6–and, more importantly, abatement of IPv4 within those agencies.  He is now a co-chair of the IPv6 Operations (v6ops) Internet Engineering Task Force (IETF) working group, and continues to advance and evangelize for the protocol.
• Buraglio, Paul Wefel, Dylan Jacob, and John J. Christman worked to design and construct an IPv6-only management plane for the ESnet6 network, requiring substantial cooperation from vendors, some of whom had not previously had any requirements for IPv6-only management capabilities.  It has allowed ESnet to inch closer to achieving the US Government’s IPv4 abatement mandates.
• Dale Carder joined ESnet in 2016 and has recently worked on an innovative use of the IPv6 packet header flow label field as a mechanism to mark IPv6 traffic based on the scientific project that is generating and receiving the traffic.  This is providing valuable information on how, for example, the various Large Hadron Collider research projects are using the network and the relative network capacity demands they are producing.

Going into the second quarter-century of production IPv6 in ESnet, IPv6 is no longer a core component of ESnet’s services.  It is the core component.  Nick and I continue to work together in our respective roles, along with other ESnet engineers, to advance the protocol, both from a strategic perspective and in the day-to-day operations of our organization.

As we move into another new era–one characterized by the movement away from dual-stack to an IPv6-only world, expect Nick, myself, and others to continue our work in bringing the Internet beyond IPv4.  In the next few weeks, I plan to revisit my “Risks of not deploying IPv6” in an effort to determine what risks have been realized and what have been mitigated over the past dozen years.  We will also be doing an overview of the most recent LHC Data Challenge, with a focus on IPv6’s nearly exclusive role as the data-transfer substrate for this major high-energy physics project. Nick will continue to advance IPv6 operations via his role in the IETF.  Members of ESnet’s Data-centers and Facilities Team are inching closer to IPv6-only data centers and zero-touch provisioning (ZTP).  My hope is that we will make as much progress in the next five years as we have in the previous twenty-five.  Regardless, ESnet’s role in the history of IPv6 has prepared us well to lead us into a bright, IPv6-only future.