The 25 Most Influential Executives Of 2012

2. John Chambers

Chairman and CEO

Chambers has led Cisco a number of times through major industry changes. But his biggest management makeover was his most audacious, pulling the networking giant back from the brink by doubling down on its core networking business. Chambers himself took the lead by in the turnaround, driving major restructuring changes, improving the company's partner relations and building up a stronger presence in the data center and virtualization markets -- all while keeping competitors such as HP and Huawei at bay.