A Milestone for the Region: How the B Root Server Came to Be Renumbered Using LACNIC IP Address Space

03/07/2023

By Carlos Martinez Cagnazzo, LACNIC CTO

A few days ago, LACNIC and the University of Southern California’s Information Sciences Institute jointly announced that one of the thirteen root servers —the b.root-servers.net server— will be renumbered using LACNIC IP address space to increase domain name system (DNS) stability and resilience. 

In this sense, it is important to stress how critical the structure of the Domain Name System is for the operation of the Internet: all DNS lookups begin at the root zone. There are thirteen different root servers, in addition to their anycast copies. These thirteen servers are managed by twelve Root Server Operators (RSOs), which serve the DNS root from thirteen named identifiers at thirteen IPv4 and thirteen IPv6 addresses.

The renumbering of the b.root-servers.net server is a milestone for LACNIC and confirms our commitment to the construction of a better global Internet. The decision was made after the University of Southern California’s Information Sciences Institute (USC/ISI), the operator of this server, signed an agreement with LACNIC to allow USC/ISI to renumber the IPv4 and IPv6 addresses of b.root-servers.net this coming 27 November 2023.

The history behind the number thirteen

The reasons that led to the existence of thirteen different servers to serve the DNS root zone and twelve Root Server Operators are basically historical.

The number thirteen dates back to the early 1980s when the DNS was created. At that time, there was a limitation on the maximum size of a DNS packet that could be successfully sent over IP. Given the critical nature of the root zone servers, the idea was that the entire process should be resolved quickly, so it was important to guarantee that it occurred in a single package. If the Internet were to be invented today, this limitation would probably not exist, but at the time and for a long time, thirteen machines seemed like they would be enough to serve the root zone.

On the other hand, also for historical reasons, most of the organizations that applied to operate these servers back then were based in the United States. Currently, two of the thirteen root servers use European / Middle Eastern region IP addresses (RIPE NCC), one uses Asia Pacific region IP addresses (APNIC), and the remaining ten use North American region IP addresses (ARIN). With this change, b.root-servers.net’s addresses will move from ARIN to Latin America and the Caribbean region (LACNIC) IP address space.

At some point in time, however, the need to add more servers became evident, as thirteen were no longer enough. 

This need eventually became a concern and having only thirteen servers began to be perceived as a risk, particularly due to issues related to the centralization of DNS traffic, the handling of security, and resilience in case of denial-of-service attacks.

Because it is very difficult to add new IP addresses, anycast copies began to appear. Anycast provides a way to announce the same prefix from several different locations. The routing system allows identifying the location closest to each user and is a way to create root server clones, so it counters the technical limitation that prevents adding new root servers.

This is where LACNIC’s journey leading to today’s announcement of this milestone comes into the picture.At a meeting of the Internet Engineering Task Force (IETF), I had the opportunity to talk with members of the RSO community and shared with them our intention to offer to collaborate with this community in some way.

Then, in July 2022 during another IETF meeting, I established contact with the leaders at the University of Southern California responsible for the operation of b.root-servers.net. Over the course of several meetings and conversations we were able to establish the shared aspirations of each organization. In December 2022, we signed an agreement and during the first months of 2023 we assigned them IPv4 and IPv6 space.

It should be noted that this is the first time that LACNIC and the region provide numbering to such a critical piece of infrastructure for the domain name system. Root server numbering changes are infrequent and represent a significant challenge for the RSO, which makes this collaboration even more relevant. It somehow highlights the fact that we have managed to build trust before the entire community. Undoubtedly, it represents a step towards maturity for our organization on the road to becoming a partner in the construction of the global Internet, which involves working for the region but in the understanding that the Internet must work well at the global level.