Cisco Systems was founded in December 1984 by two members of Stanford University computer support staff: Leonard Bosack who was in charge of the computer science department's computers, and Sandy Lerner, who managed the Graduate School of Business' computers.

Despite founding Cisco in 1984, Bosack, along with Kirk Lougheed, continued to work at Stanford on Cisco's first product which consisted of exact replicas of Stanford's "Blue Box" router and a stolen[7] copy of the University's multiple-protocol router software, originally written some years earlier at Stanford medical school by William Yeager a Stanford research engineer which they adapted into what became the foundation for Cisco IOS. On July 11, 1986, Bosack and Kirk Lougheed were forced to resign from Stanford and the university contemplated filing criminal complaints against Cisco and its founders for the theft of its software, hardware designs and other intellectual properties. In 1987, Stanford licensed the router software and two computer boards to Cisco.