Cisco's web site was offline for three hours yesterday following an electrical overload during maintenance at the company's San Jose data center. In a blog post last night, Cisco attributed the electrical problem to human error:
The issue occurred during preventative maintenance of one of our data centers when a human error caused an electrical overload on the systems. This caused Cisco.com and other applications to go down. Because of the severity of the overload, the redundancy measures in some of the applications and power systems were impacted as well, though the system did shut down as designed to protect the people and the equipment. As a result, no data were lost and no one was injured. Cisco has plans already in process to add additional redundancies to increase the resilience of these systems.
The outage came as Cisco was releasing a series of security advisories detailing new vulnerability's in the company's networking equipment.