Book excerpt: In this book, a leading expert on Cisco routing offers in-depth coverage of four key intra-domain protocols -- RIP, IGRP, OSPF, and EIGRP. Unlike other books on Cisco protocols, Alex Zinin shows you exactly what's happening inside your routers when you use these protocols -- so you can maximize your control over them, and leverage their full power. Cisco IP Routing demystifies even the most complex internals of Cisco IP routing with clear explanations, extensive visuals, and many real-world examples, configurations, and network designs. The heart of the book is its coverage of dynamic routing, starting with theory and then moving to the practical details of effective configuration. Alex Zinin also presents in-depth coverage of controlling routing by altering update flow, redistribution, and policy routing. For all network administrators, other Cisco networking professionals, and anyone preparing for Cisco's top-of-the-line CCIE exam.