In 1984, Bosack co-founded Cisco Systems with his then partner (and now ex-wife) Sandy Lerner. Their aim was to commercialize the Advanced Gateway Server. The Advanced Gateway Server was a revised version of the Stanford router built by William Yeager and Andy Bechtolsheim. Bosack and Lerner designed and built routers in their house, and experimented using Stanford's network. Initially, Bosack and Lerner went to Stanford with a proposition to start building and selling the routers, but the school refused. It was then that they founded their own company, and named it "Cisco," taken from the name of nearby San Fran"cisco". It is widely reported that Lerner and Bosack designed the first router so that they could connect the incompatible computer systems of the Stanford offices they were working in so that they could send letters to each other. However, this is an untrue legend.