Leonard Bosack
Co-founder 1984Background
Leonard Bosack was the director of computer facilities for Stanford University's Department of Computer Science in the early 1980s. A computer engineer by training Bosack was instrumental in developing the multi-protocol router technology that allowed Stanford's disparate campus networks to communicate. His technical expertise in network protocols and hardware design formed the engineering foundation upon which Cisco was built. After leaving Cisco in 1990, Bosack largely retreated from public life, focusing on philanthropic activities and private technology investments.
Role at Cisco Systems, Inc.
Cisco Systems possesses one of the most famous, romanticized, and ultimately contentious founding stories in the history of Silicon Valley. The company was founded in 1984 by a husband-and-wife team, Leonard Bosack and Sandy Lerner. They were both brilliant computer scientists working at Stanford University—Bosack managed the computer science department's mainframe computers, while Lerner managed the computers at the Graduate School of Business. The foundational technological breakthrough that birthed the company was born out of a simple, romantic necessity: they wanted to be able to email each other. However, the computer networks in their respective departments used entirely different, incompatible protocols. They could not communicate. To solve this, they designed and built a complex, multi-protocol router—a device that could translate the disparate languages of different networks, allowing them to essentially 'talk' to one another. They connected the two departments, effectively creating the first practical campus-wide local area network (LAN). Realizing the commercial implications of this technology, they founded Cisco (named after the city of San Francisco, famously retaining the lowercase 'c' in early logos and mimicking the Golden Gate Bridge). They initially built routers in their living room and funded the company by heavily mortgaging their house and running up credit card debt. In 1987, seeking scale, they brought in Don Valentine of Sequoia Capital, a legendary, aggressive venture capitalist. Valentine provided funding but demanded corporate control, eventually bringing in a seasoned CEO, John Morgridge. The relationship between the visionary founders and the ruthless, professional management team violently deteriorated. In 1990, shortly after Cisco executed a successful IPO that made the founders immensely wealthy, the board ousted Sandy Lerner. In a display of solidarity and disgust with the corporate culture, Leonard Bosack immediately resigned. While the founders walked away with $170 million, they lost control of the company they built—a company that would eventually achieve a staggering $500 billion valuation.