RSSAC050: RSSAC Statement on Identification of Root Server Operators

As described in RSSAC023 (History of the Root Server System), the organizations operating root servers and the way in which they are identified have evolved over time. As capacity demands grew, new operators and new root servers were added. In 1995, to accommodate further growth, a consistent nomenclature was adopted, which remains in use today. For example, Verisign currently operates a.root-servers.net, which has the IPv4 address 198.41.0.4 and IPv6 address 2001:503:ba3e::2:30.

An outcome of the 1995-era growth is that it became common to refer to root server operators (RSOs) with “letters” (i.e., the leftmost label in the host name) and more commonly as abbreviated identifiers (e.g., C-root, F-root). However, the use of letters as metonyms for operators over the years has led to misconceptions within the global community in how root servers are architected, and contributed to a lack of clarity around the organizations responsible for providing the service.