The Enhanced Interior Gateway Protocol (EIGRP) from Cisco Systems is one of the most widely used intra-domain routing protocols in todayis corporate networks. Although EIGRP is easily configured, the inner workings are generally not well understood. The result: nonoptimized networks that lead to chronic and costly problems requiring time and energy to solve.

EIGRP for IP is a concise, complete, and practical guide to understanding and working with EIGRP. It focuses on EIGRP in the context of IP, although the principles learned from this guide can be applied to the other major network protocols that EIGRP supports, including IPX and AppleTalk.

The book provides an overview of essential concepts, terminology, and EIGRP mechanisms, in addition to a look at the most important configuration options. It examines network design with regard to EIGRPis capabilities, offering concrete tips for specific design issues that arise in EIGRP networks. Also featured is an experience-based guide to EIGRP troubleshooting, with solutions to many commonly encountered problems.

Specific topics covered include:

• The foundations of EIGRP, including the Diffusing Update Algorithm (DUAL)
• A comparison of EIGRP to other interior gateway routing protocols
• Configuring summarization
• Standard and extended access distribution lists
• Hierarchy and redundancy in network topology
• Path selection
• Multiple EIGRP autonomous systems
• Isolating misbehaving routers
• Solving problems with neighbor relationships
• Stuck in Active (SIA) routes

Serving as both a complete reference and a practical handbook, EIGRP for IP is an essential resource for network professionals charged with maintaining an efficient, smoothly functioning network.