EIGRP for IP

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 EIGRP's 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.

Table of contents

Preface

Chapter 1: EIGRP Fundamentals

Distance Vector and Link State Protocols

Distance Vector Protocols

Link State Protocols

EIGRP Compared to Other Protocols

EIGRP: The Basics

Neighbor Relationships

Reliable Multicast

Limiting Bandwidth Consumption

EIGRP's Foundation: DUAL

The Metric

A More Practical Example

Split Horizon and Querie

Queries with No Feasible Successor

Where Does the Query End?

Deciding Where to Use EIGRP

Chapter 2: EIGRP Configuration

Starting and Running EIGRP

The network Command

The Autonomous System (AS) Number

Redistribution

Externals and Internals

Caveats

Configuring Summarization

Autosummarization

Manual Summarization

Distribution Lists

Standard Access Lists as Distribution Lists

Extended Access Lists as Distribution Lists

Hello and Hold Timers

Logging Neighbor Status

Passive Interface

Stub Neighbors

Chapter 3: EIGRP Network Design

Network Topology

Hierarchy

Redundancy

Minimizing Query Range

Summarization

Route Filtering

Stub Routers

Multiple Autonomous Systems

Multiple Routing Protocol

Path Selection Issues

Changing the Metric Components on an Interface

Offset Lists

Changing K Values

Variance

Asymmetrical Routing

Default Routing Strategy

WAN and Dial Issue

Frame Relay and Bandwidth Statements

Point-to-Point Subinterfaces

Multipoint Interfaces and Subinterfaces

Dual-Homed Remotes

Low-Speed NBMA Links and SIAs

NBMA and Split Horizon

Frame-Relay Broadcast Queue

Dial Backup Strategies

Redistribution Issues

General Issues

Forms of Redistribution

Administrative Distance

Source of Redistributed Routes

Other Design Considerations

Chapter 4: EIGRP Troubleshooting

Problems with Neighbor Relationships

One-Way Communication between Two Routers

Unicast-Only between Two Routers

Multicast-Only between Two Routers

Overburdened or Dirty Link

Stuck in Active Routes

Why Did the Route Go Active?

Why Did the Route Stay Active So Long?

Duplicate Router Ids

Failure to Converge

Simplifying the Network

Isolate Misbehaving Routers

Diagnose the Event

Glossary

Recommended Reading

Index