Cisco IT links together more than 50,000 employees at hundreds of locations worldwide over a large WAN backbone that comprises OC-12, OC-3, and DS-3 circuits that connect Cisco sites across the globe. Because Cisco relies on the WAN for business-critical applications, communications, and Internet connectivity, even a brief unplanned outage can disrupt the workflow of thousands of employees. As the network has become more complex and has evolved to handle growth, acquisitions, and technology advancements, the Cisco WAN has been able to achieve almost 99.999 (“five-nines”) percent availability.
This best practices describes in detail how the Cisco IT WAN team achieved high availability by developing a systematic approach to assessing and improving network design, operations, management, and support, including:
- Measuring availability and using outage alerts and change management
- Implementing route summarization to conserve memory and CPU resources
- Standardizing hardware and software, as well as upgrade processes
- Managing configurations, changes, and outages
