A power outage caused by an accident at a San Jose data center blacked out the Cisco.com site for three hours Wednesday.
Cisco was able to communicate the problem over its official blog, but word about the cause came via e-mail from a spokeswoman at 5 p.m. EST.
"We have traced the cause of the issue to an accident during maintenance of a San Jose data center that resulted in a power outage in that facility," the spokeswoman said. "We would like to thank our customers and partners for their patience. We expect to resolve the issue shortly."
Users around the U.S. reported the outage sometime before 2 p.m. EST via various blogs, and then noted that service was restored about 4:50 p.m. EST.
Cisco did not describe the duration of the outage or exactly what happened and why a backup system was not available to quickly restore service, as would be common with a large Web site -- especially one run by the largest networking vendor in the world.
Bloggers questioned what was happening, and asked whether such a normally resilient site could have been attacked before they found out about the data center accident.
"With all its mighty power, network behemoth's main website www.cisco.com is down," wrote slidersv at Slashdot. "No news describing the reason as of now. I have tried accessing the site for the past hour, since our operations heavily rely on Cisco online documentation, with no luck. After all the advocacy of high-availability, security and performance.... Oh, the irony."