Cisco IOS in a Nutshell

Routers are the glue that holds the Internet together, and Cisco Systems--holding roughly 70% of the market--is the most prominent router manufacturer. Cisco's routers come in all shapes and sizes and almost all of them, from the smallest to the largest, run the IOS operating system. IOS is an extremely powerful and complex operating system, with an equally complex configuration language. There are many commands, with many options, and if one thing is configured incorrectly, the entire company could find itself offline.

Cisco IOS in a Nutshell covers IOS configuration for the TCP/IP protocol family. The book is divided into two parts: the first part includes chapters on the user interface, configuring lines and interfaces, access lists, routing protocols, and dial-on-demand routing and security; the second part is a classic O'Reilly-style quick reference to all the commands that you need to work with TCP/IP, including the lower-level protocols on which it relies, and lots of examples of the most commonly encountered configuration steps for the routers themselves.

Table of Contents

Preface   

Chapter 1. Getting Started  

      Introduction   

      IOS User Modes   

      Command-Line Completion   

      Get to Know the Question Mark   

      Command-Line Editing Keys   

      Pausing Output   

      show Commands   

Chapter 2. IOS Images and Configuration Files  

      IOS Images   

      Using the IOS Filesystem for Images   

      The Router's Configuration   

      Loading Configuration Files   

Chapter 3. Basic Router Configuration  

      Configuration Soapbox   

      Setting the Router Name   

      Setting the System Prompt   

      Configuration Comments   

      The Enable Password   

      Mapping Hostnames to IP Addresses   

      Setting the Router's Time   

      Enabling SNMP   

      Cisco Discovery Protocol   

      System Banners   

Chapter 4. Line Commands  

      What Is a Line?   

      The line Command   

      The Console Port   

      Virtual Terminals (VTYs)   

      Asynchronous Ports (TTYs)   

      The Auxiliary (AUX) Port   

      show line   

Chapter 5. Interface Commands  

      Naming and Numbering Interfaces   

      Basic Interface Configuration Commands   

      The Loopback Interface   

      The Null Interface   

      Ethernet and Fast Ethernet Interfaces   

      Token Ring Interfaces   

      ISDN Interfaces   

      Serial Interfaces   

      Asynchronous Interfaces   

      Interface show Commands   

Chapter 6. Frame Relay and ATM  

      Frame Relay   

      ATM   

Chapter 7. Lists and Queues  

      Access Lists   

      Specific Topics   

      Managing Priorities with Queues   

Chapter 8. IP Routing Topics  

      Routing Protocol Topics   

      Static Routes   

      Split Horizon   

      Passive Interfaces   

      Fast Switching and Process Switching   

Chapter 9. Interior Routing Protocols  

      RIP   

      IGRP   

      EIGRP   

      OSPF   

Chapter 10. Border Gateway Protocol  

      Introduction to BGP   

      A Simple BGP Configuration   

      Route Filtering   

      An Advanced BGP Configuration   

      Neighbor Authentication   

      Peer Groups   

      Route Reflectors   

      BGP Confederacies   

Chapter 11. Dial-on-Demand Routing  

      Configuring a Simple DDR Connection   

      Sample Legacy DDR Configurations   

      Dialer Interfaces (Dialer Profiles)   

      Multilink PPP   

      Snapshot DDR   

Chapter 12. Special Topics  

      Bridging   

      Hot Standby Routing Protocol (HSRP)   

      Network Address Translation (NAT)   

      Tunnels   

      Encrypted Tunnels   

Chapter 13. Router Security  

      The enable Password   

      Features to Disable on Your Gateway Routers   

      Use a Warning Banner   

      Protect VTYs with an Access List   

Chapter 14. Troubleshooting and Logging  

      ping   

      trace   

      Debugging   

      Logging   

Chapter 15. Quick Reference  

Index