We all want high availability in our networks, but what does this really mean? What technologies and techniques can bring high availability to the enterprise? In this course, you'll learn about high availability and some of the tried and true techniques that make it a reality. You'll explore the powerful Layer 2 feature Bidirectional Forwarding Detection along with its key design principles. Next, you'll examine many aspects of designing a successful Layer 2 infrastructure in your enterprise, including important design decisions. You'll learn about the design of the most critical parts of the SD-Access solution, the network underlay and overlay. Finally, you'll explore the complexities of an SD-Access solution and how to ensure components are designed and implemented properly for an SD-Access deployment. This course can be used in preparation for the 300-420: Designing Cisco Enterprise Networks (ENSLD) certification exam.