The Cisco website went down for three hours on Wednesday, preventing users gaining access to online training materials and support documentation for Cisco equipment.
"Cisco experienced some facility issues that impacted on services to Cisco.com," the company said in a post to its official blog -- which was still operational.
Cisco confirmed that the outage was down to human error at one of its datacentres. No data had been lost as a result of the downtime, the company added.
Bloggers were keen to move on the news about what was happening, and asked why such a site, normally known for its reliance, could have been brought down before Cisco was aware of the problem in the datacentre.
"With all its mighty power, the 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."