the hierarchical Domain Name System that supports most modern Internet communication. Verisign also generates the globally recognized root zone file and is also responsible for processing changes to that file once they are ordered by ICANN via IANA and approved by the U.S. Department of Commerce. Changes to the root zone were originally distributed via the A root server, but now they are distributed to all thirteen servers via a separate distribution system which Verisign maintains. Verisign is the only one of the 12 root server operators to operate more than one of the thirteen root nameservers. The A and J root servers are "anycasted” and are no longer operated from any of the company's own datacenters as a means to increase redundancy and availability and mitigate the threat of a single point of failure. In 2016, the Department of Commerce ended its role in managing the Internet's DNS and transferred full control to ICANN. While this initially negatively impacted VeriSign's stock, ICANN eventually chose to contract with Verisign to continue its role as the root zone maintainer. VeriSign's naming services division dates back to 1993 when Network Solutions was awarded a contract by the National Science Foundation to manage and operate the civilian side of the Internet's domain name registrations. Network Solutions was the sole registrar for all of the Internet's non-governmental generic top-level domains until 1998 when ICANN was established and the new system of competitive registrars was implemented. As a result of these new policies, Network Solutions divided itself into two divisions. The NSI Registry division was established to manage the authoritative registries that the company would still operate, and was separated from the customer-facing registrar business that would have to compete with other registrars. The divisions were even geographically split with the NSI Registry moving from the corporate headquarters in Herndon, Virginia, to nearby Dulles, Virginia. In 2000, VeriSign purchased Network Solutions taking over its role in the Internet's DNS. The NSI Registry division eventually became VeriSign's naming services division while the remainder of Network Solutions was later sold by Verisign in 2003 to Pivotal Equity Group. Company properties Following the sale of its authentication services division in 2010, Verisign relocated from its former headquarters in Mountain View, California, to the headquarters of the naming division in Sterling, Virginia (originally NSI Registry's headquarters). Verisign began shopping that year for a new permanent home shortly after moving.