Information Technology Governance Committee (ITGC)

Letters to Community: IPv4 Memo


Next Generation MITnet – June 28, 2017

June 28, 2017

To Members of the MIT Community,

As Co-Chairs of the Information Technology Governance Committee (ITGC), Professor Karen Gleason and I want to inform you about some changes that are being made to MITnet, and to address some of the concerns we’ve heard about certain aspects of these changes.

The Future of MITnet

As was announced this past April 19, in a letter sent to the community by Provost Martin Schmidt and Executive Vice President & Treasurer Israel Ruiz, MIT is migrating to IPv6, and in the process is consolidating our in-use IPv4 address space to facilitate the sale of excess IPv4 capacity. As part of the renumbering effort, we are also provisioning our infrastructure to accommodate private as well as public IPv4 addresses. All IPv6 addresses will be public.

The decision to sell a portion of this excess IPv4 space was thoroughly vetted through MIT’s IT governance process, as well as with the Academic Council. MIT is using these new funds to provide funding for research and education, and using this opportunity to upgrade and modernize MITnet.

What is the current status?

We transferred our unused IPv4 address blocks at the end of April 2017. To meet our next contractual requirement we needed to migrate a small number of in-use IPv4 addresses in June 2017. To do this, we selected address blocks associated with buildings W2, W5, W8, W64, E1, 50, W16, W15, W34, and W51c – buildings with low numbers of devices (approximately 50 total). After consulting with the occupants, none of the devices were identified as needing public addresses, so the IPv4 addresses for these devices were changed to private on Friday, June 23. Later that evening it was determined that one of these devices did in fact need a public address. A trouble-ticket was submitted at about midnight, and the problem was resolved by Saturday afternoon.

With our most pressing requirements behind us, we now have time to pause and engage with our community to coordinate plans for rolling out the new dual-stack architecture, and consolidating our in-use address space in time to meet our next milestone scheduled for June 2018.

We have already received a lot of feedback, thank you. And, we are looking forward to the opportunity to collaborate will stakeholders, thought leaders, and other members of our community over the Summer to chart the best paths forward for the Institute. We will also consult with the IT Policy Committee as these plans progress.

How can we balance openness and security?

We intend to balance openness and security by providing options for public as well as private addresses – options similar to those we used in the transition to firewalls a few years back.

MIT has operated its network in a completely open fashion since its inception over 30 years ago. During that time, the Internet has changed quite a bit, evolving beyond just a research platform into critical infrastructure for the Institute. Consequently, we are working towards a future with a more balanced approach between openness and security.

The planned inclusion of NAT technology has raised some concerns about its effect on the ability of students, faculty, and researchers to develop projects, build skills, discover, experiment and innovate. Therefore, we want to make clear our commitment to preserving these capabilities for experimentation and innovation. There will be both public and private addressing options available, and faculty, researchers, staff, and students will be able to self-select whichever option best meets their individual needs. Simply put, no servers or devices requiring public addresses will be placed behind a NAT, so the use of NAT technology for devices needing private addresses will have no impact on how devices needing public addresses operate. We plan to work out the details of this process with the community, as mentioned above.

Going Forward

IS&T is maintaining an FAQ to address the many questions we have received. If you have additional questions or concerns, we encourage you to submit them to

We appreciate your feedback, and invite you to continue to engage with us as we move to the Next Generation of MITnet. We will be reaching out to thought leaders, stakeholders, and other interested members of our MIT community over the Summer.

John Charles is available to answer any questions you may have.


Anthony Sharon
Co-Chair, IT Governance Committee
Deputy Executive Vice President