The No. 1 thing the co-inventor of the ethernet learned from his mentor, Steve Jobs

3Com went on to go public in 1984, and in 1999, its peak year for sales, the networking tech company did $5.7 billion in sales. In 2010, 3Com merged with Hewlett Packard. Metcalfe considered Jobs a mentor. “He was 10 years younger than me, so that was odd. I had...