Fuzzball router

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' 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 . They were the first routers to implement key refinements to TCP/IP like variable-length subnet masks.

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