Cisco Cookbook

Chapter 2. Router Management

2.0. Introduction

Like the previous chapter, this chapter also looks at system management issues on the router. So far we’ve looked primarily at general system administration issues such as filesystem management, but here we will discuss management and tuning issues related to router performance. You’ll also learn some of the techniques needed to deal with disaster scenarios, such as how to create exception dumps.

Cisco’s IOS supports a variety of special purpose protocols and services. Some of these are useful for network management and administration, while others are more useful for testing purposes. One of the handiest features is the Cisco Discovery Protocol (CDP), which allows you to see useful information about the Layer 2 connections between Cisco devices. This chapter shows how to use CDP and covers some of its well-known security problems.

Disabling is often the best strategy for several other services. Some, like the HTTP management interface and various test protocols (lumped together under the title of the TCP and UDP “small servers”), serve no real purpose in most production networks and are disabled by default. Others, like DNS, do have useful functions and are enabled by default.

We will discuss several important administrative features such as different methods for handling the hostnames of other network devices and command aliases to make complex commands easier to remember and type. The chapter concludes with a set of four useful scripts ...