IS-IS is making a big comeback, EIGRP is still in use in many organizations, and OSPF is considered the most scalable and advanced protocol we can use for an IGP. In this course, you'll learn about all three. First, you'll examine the techniques behind scalable IS-IS routing designs and have a chance to review key IS-IS concepts. Next, you'll move on to learn about key design concepts that can help ensure your EIGRP implementation is successful. Finally, you'll also explore the techniques for building a scalable and robust OSPF infrastructure. This course can be used in preparation for the 300-420: Designing Cisco Enterprise Networks (ENSLD) certification exam.