Technology’s older generation of rebels has now almost completely disrupted itself.

Over the last few years, longtime leaders of industry giants like Microsoft, Oracle, Intel and IBM have stepped down, in departures that signal the passing of one tech era and the beginning of another. In many cases, their successors now struggle with updating their companies, which were largely built in a world of personal computers and packaged software, for one of mobile devices, cloud computing, sensors and software everywhere.

On Monday, perhaps the last veteran leader of the old guard signaled it was time to leave the corner office — if only for a move down the hall. John T. Chambers, chief executive of Cisco Systems since 1995, said he was stepping down effective July 26, to be succeeded by a longtime Cisco sales executive.

“He is the last of the lions, presiding over years of incredible growth,” said George Colony, chief executive of Forrester Research, a market research firm.

Mr. Chambers’s successor, Charles H. Robbins, is 49, and joined Cisco, the networking equipment maker, in 1997, just two years after Mr. Chambers became C.E.O. Mr. Chambers, 65, will remain as executive chairman. The company said that Mr. Chambers would spend time supporting the company’s new chief and “engaging closely with customers and governments around the world.”