About b.root-servers.net

The b.root-servers.net critical infrastructure provides Domain Name Service for the DNS root zone, handling 5 billion requests a day as a public service to the Internet and to support DNS and naming research.

More information: about us, about our principals. Please contact us if you have additional technical or operational questions.

What is the DNS?

The Domain Name System (DNS) provides names for things on the Internet like web pages (such as www.usc.edu, USC’s home page) and e-mail addresses (like the @usc.edu in example@usc.edu). Typically it maps these human-readable names into computer-relevant information like IP addresses and e-mail servers.

Learn more about the DNS.

What is a DNS Root Server?

The DNS is hierarchical, with “com”, “edu”, country codes, and many other top-level domains (TLDs) as the user-perceived starting point. A “Root Server” is where computer software goes to find how to contact all top-level domains. Simply put, the DNS root servers bootstrap the entire Internet naming system we all know and love. There are 12 organizations that collaboratively manage over 1700 root server instances. The map on root-servers.org let’s you see them all!

Learn more about root servers.

Why does ISI run a root server?

The Domain Name System was created in 1983 by Paul Mockapetris at USC/ISI. ISI’s internet DNS legacy comes from the beginning when ISI ran the only root servers and today continues to run one of them: b.root-servers.net. We continue to operate a root server as a public service to the Internet and to support DNS and naming research.

Learn more about ISI’s DNS root service.


The USC/ISI Root Server operation staff greatly appreciates and thanks the support of our donors and partners. If you are interested in sponsoring our root service with hardware, hosting, or financial support please contact us. For further information about our sponsors, please see our support page.

Our Research Focus

The b.root-servers.net server operators strive to support the DNS ecosystem through active research projects and related software development.

Current Research Projects

  • DIINER supports new new research in Internet naming and trust. Our goal is to support research and ease transition from research to operational deployment, while preserving stability. We support an accessible DNS Root testbed for use by researchers and hold annual “DINR” research workshops.
  • LocalRoot allows you to serve a cached copy of the DNS Root Zone from your recursive resolver, similar to RFC8806.
  • CLASSNET will develop a framework for collaborative, community-driven enrichment and labeling of data, enabling use of our datasets for machine learning in networking and security.

Software development highlights

Learn more about our DNS related research and DNS standardization activities.