He should know. After passing a Cisco certification written exam once, Campbell failed the lab test several weeks later. "I thought that I had it after the written, but then I took the lab. Oh boy," he recalled.

Cisco runs a boot camp to prepare for the tests, but Campbell said most engineers self-study for the written portion. "You have to have a good base of engineering knowledge first," from school and work, he said, if only to fully understand the textbooks.

For the CCIE security exam, one Cisco expert in an online blog recommended using seven different text books to prepare for the two-hour written exam. The 100-question security test has multiple-choice and fill-in-the blank questions. For the lab test, the online testing rubric lists more than 100 devices, software and security attacks that engineers must be prepared to troubleshoot.

The average pass rate has been 26% for both written and lab tests since the start of the program in 1993, although many people take the exam again if they fail, a Cisco spokeswoman said. About 12,000 people take the written exam each year, with about 9,000 taking the lab test annually. In all, there are fewer than 14,000 CCIEs in the world in five areas including voice, routing and switching, security, service provider and storage networking.

Several engineers taking last week's exam said the CCIE is expected to confer a status on them that can lead to better job assignments, pay raises and perhaps an easier pathway to another job. Jason Witty, director of IT for Southern Wine and Spirits in Miami, said he recently opened a new warehouse with wireless and other communications technology with the help of a CCIE working for IBM as a consultant. The CCIE, Joe Tejeda, was able to train technical staffers at the warehouse and helped in preparing the warehouse launch.