The Domain Name System is a distributed hierarchical database of resource records that permit (among other things) the translation of hostnames into IP addresses and vice versa. The root of this hierarchy is anchored on 13 domain name servers scattered across the globe. The D Root Server is operated by the Advanced Cyberinfrastructure and Internet Global Services group within the Division of Information Technology at the University of Maryland in College Park, MD. The University has been operating a root server at the request of the Internet Assigned Numbers Authority (IANA) since 1988. The University serves the root zone as published by IANA without modification. The University, as operator of d.root-servers.net, recognizes the following organizations as current root server operators and endeavors to coordinate operational service with them:
- Verisign, Inc.
- University of Southern California, Information Sciences Institute
- Cogent Communications, Inc.
- University of Maryland
- NASA Ames Research Center
- Internet Systems Consortium, Inc.
- US Department of Defense, Network Information Center
- US Army Research Laboratory
- Netnod
- RIPE NCC
- ICANN
- WIDE Project