Introduction

Routing is an essential element of all but the smallest data communications networks. At one level, routing and the configuration of routers are quite simple. But as internetworks grow in size and complexity, routing issues can become at once both large and subtle. Perversely, perhaps, I am grateful for the difficult problems large-scale routing can present ”as a network systems consultant, these problems are my bread and butter. Without them, the phrase "You want fries with that?" could be an unfortunate part of my daily vocabulary.

Cisco Certified Internetwork Experts are widely recognized for their ability to design, troubleshoot, and manage large internetworks. This recognition comes from the fact that you cannot become a CCIE by attending a few classes and then regurgitating some memorized facts onto a written test. A CCIE has proven his or her expertise in an intense , famously difficult hands-on lab exam.