On Thursday evening, Oracle announced to much surprise that founder and CEO Larry Ellison will step down from his long-held post. He’ll become executive chairman and CTO, ceding the top spot to SafraCatz and Mark Hurd after 37 years. Ellison, 70, is by far the longest-serving chief in tech, but he’s hardly the only one whose time at the top can be measured by the decade.

Cisco CEO John Chambers took the helm of the San Jose, Calif.-based networking company in January 1995 and presided over one of the great runs in the industry, pushing the company onto the Fortune 500 list (#332, in 1997) and past a market capitalization of $100 billion (1998) to become, for a brief moment in 2000, the most valuable company in the world (at about $550 billion). Then the market’s bottom fell out in the dot-com bust.

In 2012, Chambers said that he expected to retire in two to four years, naming development and sales president Robert Lloyd, field operations SVP Chuck Robbins, and services SVP EdzardOverbeek as possible successors. For this reason, an unusual amount of anxiety and breathless anticipation accompanied Cisco’s most recent earnings report. The date, August 14, was just nine days before Chambers’ 65th birthday. Could investors expect succession news with the financial results?

It came and passed with little leadership news, of course—another debunked retirement rumor in a long line of them that stretches back well over a decade. Chambers’ retirement has been “imminent” for years, yet the test of time has shown each and every rumor to be greatly exaggerated. This one was no exception, despite news of thousands of layoffs.

“John has consistently said that the next time he talks about succession is when he announces succession,” a company spokesman tells Fortune. “This has not changed.”

Two things have changed, however. First, Chambers is now 65, the symbolic age that at many companies would mandate retirement. Second, the research firm Gordon Haskett issued a report stating that the firm still expects Chambers to announce his retirement soon, calling Cisco “a company operating without a named successor.”

The average tenure of a CEO is roughly eight years. Chambers has been in the role for almost 20. What has allowed him to buck that trend—and how much longer can he last?

‘Networking is a brutal business’

“John Chambers has had a remarkable ride by any measure,” says Charles King, principal analyst with Pund-IT.

That ride began back in 1995, when Chambers, then 46, took Cisco’s top job. At the time, the rise of the Internet had put a lusty wind in Cisco’s sails, and the company’s routers and switches soon came to be viewed as key vertebrae in the backbone of an increasingly connected world. Since March 2000, when Cisco briefly edged out Microsoft as the world’s most valuable company, there have been plenty of rough patches: several rounds of layoffs, failed acquisitions (remember the Flip camcorder?), and lackluster stock performance.

Cisco under Chambers has also been under considerable pressure in recent years from emerging technology trends that challenge its core businesses. One example? Software-defined networking, an approach that is considered to be cheaper and more flexible than the traditional networking equipment upon which Cisco built its name.

Cisco does have an answer for that, which it calls Insieme. (“I see SDN as something we’ll embrace and get the benefits of,” Chambers said in the company’s most recent earnings call.) Still, there has been “some public grumbling about the company being late to that game and with less innovative products than some others,” King points out, even as Cisco remains the leader in its core networking markets and performs well in newer areas like x86 servers.

“Networking as a whole is a brutal business because, unlike computing, applications haven’t changed that much—switching is switching and routing is routing—while semiconductor progress has commoditized costs and put downward pressure on prices,” says Peter Christy, a research director for networking with 451 Research. “Chambers has driven many attempts to broaden Cisco’s portfolio and grab more wallet share. Some, like server computing or IP telephony, have succeeded brilliantly. Others, like consumer efforts—e.g. the Flip camera—not so.”

Those failed bets are fodder for critics calling for Chambers to retire. Supporters, meanwhile, say he has shown resilience as well as the confidence to make bets that may not work out.

Christian Renaud, a senior analyst also with 451 Research, worked under Chambers at Cisco for more than a decade in the late 1990s and early 2000s. He credits Chambers’ tenure for a long-view perspective that short-term CEOs often miss. “He steered the company from just over a thousand people when I started working for him to over 65,000 when I left,” Renaud recalls. “Under his leadership, Cisco has successfully weathered large market transitions, and not only survived but thrived.”

Other former colleagues tell a similar tale. “Having known him for more than two decades, I am amazed at his nonstop energy and decisive courage in navigating Cisco through both its highs and lows,” says ex-Cisco exec Jayshree Ullal, who is now chief executive of Arista Networks, which competes with Cisco.

It is an inherent part of the CEO role that you get credit for the good times and blame for the bad. Take Cisco’s layoffs, for example—Chambers is equally responsible for those as he is for the company’s growth, Renaud says. “I know how much the layoffs in 2001 emotionally impacted John, as I suspect the layoffs in 2009 did as well,” he says. “This can’t be easy for him, but it is part of the cycle of every business.”

Chambers spent many years in sales during the early part of his career. It’s possible that background may be part of what has helped him endure. “Great salesmen run on a special kind of real-world optimism. You know—head in the clouds, feet on the ground,” says John Waters, editor-at-large for Application Development Trends and author of John Chambers and the Cisco Way. “Add an almost devout focus on the customer, and you’ve got a combo of personal traits that surely helped to keep him in the big chair.”

‘I expect some investors are wondering’

Chambers’ two-decade tenure is relatively unusual in the technology industry, but it’s far from unprecedented. Of those chief executives active in the role today, Activision Blizzard’s Robert Kotick, Microchip Technology’s Steve Sanghi, and Nvidia’s Jen-Hsun Huang exceed Chambers’ tenure. Concur’s Steven Singh and Amazon’s Jeff Bezos aren’t far behind.

“IT CEOs typically call the shots on their career paths until they lose the faith of their customers or shareholders,” King says. That usually happens in one of three ways: Either the CEO misses a key evolutionary shift in the industry, wastes money on unsuccessful products, or fails to deliver the returns desired by large institutional investors, he says.

In Chambers’ case, the last reason is the most pressing. “Much like Microsoft under [Steve] Ballmer, Cisco shares have for the past decade been mired in a fairly narrow trading range—between $15 and $30—and the stock has mostly failed to catch fire in major market advances, including the one currently under way,” King says. “Since the company offers only relatively small dividends—currently $0.19 per share, compared to $0.28 per share for Microsoft and $1.10 per share for IBM—I expect some Cisco investors are wondering how the company might fare under a different leader.”

Cisco has plenty of top talent in its executive suite, says Robert Bradford, president and CEO of the Center for Simplified Strategic Planning. “If the company were in a more difficult strategic situation, they might look outside,” he says. “Given their performance, I wouldn’t.”

Chambers has done all the right things to ensure a smooth succession, says Scott Saslow, founder and CEO of the Institute of Executive Development. The process so far seems “near perfect,” he says: Chambers has pre-announced his intentions years in advance; he has mentioned specific executives who are internal candidates for the job; he would leave the company on very solid financial footing. “It is rare to see all three of these conditions,” Saslow says.

Most boards of directors facing a transition aren’t as lucky as Cisco’s will be, Saslowadds. “The vast majority don’t think they have enough ready successors for the CEO position,” Saslow says. “Given that Chambers has stated that Cisco has several, they appear to be way ahead of the market.”

Cisco’s retirement rumors once worried Renaud, the 451 Research analyst. That’s no longer so. “John has done a great job in recent years of building a succession plan and strong bench in preparation for an inevitable transition,” Renaud says. “That wasn’t always the case, and I’d say his bench now is the strongest I’ve ever seen it. If he was going to retire, the company would be left in good shape.”

上周四晚间，甲骨文公司（Oracle）突然宣布，创始人拉里•埃里森将卸任CEO。埃里森担任该职位已有37年，以后他将担任该公司执行董事长兼首席技术官，萨夫拉•卡茨和马克•赫德将出任思科公司联席CEO。年届七旬的埃里森，是科技领域迄今为止任职时间最长的首席执行官，不过，担任首席执行官数十年之久的，并非只有埃里森一人。

1995年1月，思科公司（Cisco）首席执行官约翰•钱伯斯开始掌舵这家位于加利福尼亚州圣荷西的网络公司，在他的领导下，思科创造了互联网历史上最辉煌的业绩之一，并跻身《财富》美国500强之列（1997年位列第332名），其市值超过1000亿美元（1998年），2000年甚至一度成为世界上最有价值的公司（估值约5500亿美元）。后来，网络泡沫破灭，市场形势急转直下。

2012年，钱伯斯表示他将在两到四年内退休，并指定开发和销售部总裁罗伯特•劳埃德、现场运营高级副总裁查克•罗宾斯以及服务部高级副总裁艾德扎德•奥弗比克作为继任者候选人。正因如此，不久前，人们在等待思科发布最新盈利报告时，怀揣着特别的焦虑和期待。那天（8月14日）离钱伯斯的65岁生日只有9天。思科在发布财务业绩时，是否会发布有关继任的消息？

当然，那天没有发布关于领导层更替的消息，再次击破传言。一直以来这种传言不胜枚举，甚至可以追溯到十年前。多年以来，一直有消息称钱伯斯即将退休，但时间证明每次都是谣言。这次也不例外，尽管有消息称思科将裁员数千人。

思科发言人向《财富》表示：“约翰一直说，下一次他提到继任问题时，他就会宣布继任者人选。这一点没有变过。”

但是，有两件事情发生了变化。首先，钱伯斯现在65岁了，在很多公司，掌门人到了这个年龄都会被强制退休。第二，调研公司Gordon Haskett发布的一份报告仍预计钱伯斯即将宣布退休，称思科是“一家没有指定接班人的公司”。

首席执行官的平均任期大约是8年。钱伯斯已担任该职位近20年。他是如何做到的？他还能干多久？

“网络行业很残酷”

Pund-IT公司首席分析师查尔斯•金表示：“无论以什么指标来衡量，约翰•钱伯斯这一路走来都取得了令人瞩目的成就。”

1995年，当时46岁的钱伯斯开始担任思科首席执行官。彼时，互联网的兴起推动思科急剧发展壮大，公司的路由器和交换机很快被视为日益网络化世界的重要支柱。2000年3月，思科曾一度超越微软(Microsoft)，成为全球最具价值的公司，此后经历了诸多困难时期：几轮裁员、并购失败（还记得收购Flip摄像机公司那场闹剧吗？），股价低迷。

近年来，随着新兴技术趋势不断挑战思科的核心业务，钱伯斯领导的这家公司也一直承受着巨大的压力。举例来说，软件定义网络(SDN)比传统的网络设备成本更低且更灵活，而思科当年正是靠传统网络设备成名的。

思科确实找到了应对之策，那就是收购Insieme。（钱伯斯在公司最近的财报电话会议上表示：“我认为SDN是未来的趋势，我们会从中受益”。）但是，金指出，尽管思科在其核心网络市场仍然是领先者，而且在x86服务器这样的新领域运营良好，仍然有人“抱怨思科行动太迟缓，创新产品也少于其他公司。”。

负责与451 Research研究公司协作的研究主管彼得•克里斯蒂表示：“整体而言，互联网是个残酷的行业，因为它不像计算机，应用程序并没有发生太大的变化，交换还是交换，路由还是路由，然而半导体的进步已使成本商品化，且对价格构成下行压力。钱伯斯推动了许多尝试，以拓展思科的产品组合，并抢占更大的市场份额。有些尝试很成功，如服务器计算和IP电话，有些并不成功，如Flip摄像机。”

那些失败的案例成为批评者们要求钱伯斯退休的理由。而支持者则表示，钱伯斯表现出了韧性和愿意冒险尝试的信心。

451 Research研究公司资深分析师克里斯汀•雷诺在20世纪90年代末和本世纪初曾在思科钱伯斯手下工作了十多年。他赞赏钱伯斯在其任期内着眼于长远视角，而这往往是任期较短的首席执行官所忽视的。雷诺回忆道：“我刚开始在他手下工作时，公司只有1000多人，我离开的时候，他已经使思科成长为拥有65000人的公司。在他的领导下，思科成功抵御了大规模市场转型，不仅存活下来，而且实现了蓬勃发展。”

钱伯斯的其他前同事也有类似看法。前思科高管杰西瑞•乌拉尔现在是思科竞争对手Arista Networks公司首席执行官，他说，“我认识他超过二十年，他领导思科经历起起伏伏，始终干劲十足、果断无畏，这令人钦佩。”

担任首席执行官，在公司顺风顺水时会得到褒奖，在公司陷入困境时则会遭到指责。以思科的裁员为例，钱伯斯是促进公司增长的功臣，但同样要为裁员负责。雷诺表示：“我知道2001年的裁员令约翰很不好受，2009年的裁员也是一样。这对他来说也不容易，但这是每个企业发展周期的必经之路。”

在其职业生涯的早期阶段，钱伯斯从事过多年的销售工作。可能正是这种背景，帮助他坚持了下来。《应用开发趋势》(Application Development Trends)特约编辑，《钱伯斯的思科之道》(John Chambers and the Cisco Way)一书作者约翰•沃特斯表示：“伟大的推销员都有一种特别的现实乐观主义态度。他们异想天开，同时又脚踏实地。此外，钱伯斯对客户极其关注，这些个性使他能稳坐首席执行官交椅。”

“我预计部分投资者有想法”

在科技行业，钱伯斯担任首席执行官达二十年，这确实不寻常，但并非前所未有。目前的首席执行官中，动视暴雪（Activision Blizzard）的罗伯特•科蒂克、微芯科技（Microchip Technology）的史蒂夫•桑吉和Nvidia的黄仁勋，任期都超过了钱伯斯。Concur公司的史蒂芬•辛格和亚马逊（Amazon）的杰夫•贝佐斯的任期也没短多少。

金说道：“IT行业首席执行官通常对自己的职业道路有决定权，除非客户或股东对他们失去信心。这通常有三种情况：首席执行官错过了行业的关键变革，在失败的产品上浪费大量资金，或未能向大型机构投资者提供理想的回报。”

就钱伯斯的情况来看，最后一个原因是最迫切的问题。金说道：“就像在鲍尔默领导下的微软一样，过去十年，思科的股价一直陷于每股15美元至每股30美元的狭窄交易区间，而且思科股票也未能从重大的市场上涨中受益，在目前的市场涨势中也是如此。由于公司提供的股息较少，目前每股股息为0.19美元，而微软每股股息为0.28美元，IBM每股股息为1.10美元，我预计部分思科投资者可能有更换领导人的想法。”

简化战略规划中心(Center for Simplified Strategic Planning)总裁兼首席执行官罗伯特•布拉德福德表示，思科的高管人员中有大量顶尖人才。他说：“如果公司处于更加艰难的战略形势下，思科可能会从外部聘请领导者。鉴于公司高管人员的表现，我认为不会从外部聘任。”

高管理发展协会（Institute of Executive Development）创始人兼首席执行官斯科特•萨洛表示，钱伯斯已为顺利交接做好了一切准备。目前看来这个过程“近乎完美”，他表示，钱伯斯在几年前就宣布了退休的意图；他提出了具体高管人员作为继任者内部候选人；他离任时公司的财务状况将非常稳健。萨洛说：“同时做到这三点很难得。”

萨洛补充道：“大部分董事会在面临转型时没有思科那么幸运。绝大多数董事会认为，他们没有足够的继任者来担任首席执行官一职。而钱伯斯表示，思科有好几位候选人，在这方面，该公司似乎遥遥领先于同行。”

思科的退休传闻，一度令451 Research公司的分析师雷诺甚为担忧。现在他不再担忧了。雷诺说：“最近几年，约翰制定了良好的继任计划，并为不可避免的过渡，准备了强大的候选人阵容。不是每个首席执行官都能做到这一点，我要说，他的候选人阵容是我见过最强大的。如果钱伯斯退休，思科将运营良好。”