Fuzzball routers were the first modern routers on the Internet. They were DEC LSI-11 computers loaded with the Fuzzball software written by David L. Mills (of the University of Delaware). The name "Fuzzball" was the colloquialism for Mills's routing software. Six Fuzzball routers provided the routing backbone of the first 56 kbit/s NSFNET, allowing the testing of many of the Internet's first protocols. It allowed the development of the first TCP/IP routing protocols, and the Network Time Protocol. They were the first routers to implement key refinements to TCP/IP such as variable-length subnet masks.
- Carl Malamud (1992). Exploring the Internet: a technical travelogue. Prentice Hall. pp. 88. ISBN 0-13-296898-3.
- "Fuzzball: The Innovative Router". Archived from the original on 2011-05-20.
- Mills, D.L. (August 1988). The Fuzzball (PDF). ACM SIGCOMM 88 Symposium. Palo Alto, CA. pp. 115–122.
- Mills, D.L.; Braun, H.-W. (August 1987). The NSFNET Backbone Network (PDF). ACM SIGCOMM 87 Symposium. Stoweflake, VT. pp. 191–196.
- David L. Mills (29 November 2007). "The NSFnet Phase-I Backbone and The Fuzzball Router" (PDF). Presentation at the NSFNET Legacy event, 2007. pp. 38–48.
- Fuzzball: A page by David L. Mills, including links to some of his papers on the Fuzzball.
- Charles M. Kozierok (2005). The TCP/IP guide: a comprehensive, illustrated Internet protocols reference. No Starch Press. pp. 679–681. ISBN 1-59327-047-X.
- "Technical History of NTP", Computer Network Time Synchronization, 2010, pp. 377–396, doi:10.1201/b10282-20, ISBN 978-1-4398-1463-5
- John T. Moy (1998). OSPF: anatomy of an Internet routing protocol. Addison-Wesley Professional. p. 20. ISBN 978-0-201-63472-3.