Todd Lammle's CCNA/CCENT iOS Commands Survival Guide

Todd Lammle, CCSI, CCNA/CCNP R/S, CCNA/CCNP Voice, CCNA/CCNP Data Center, CCNA/CCNP Wireless, CCNA/CCNP Security, is the authority on Cisco networking. His three decades of real-world experience is prevalent in his writing. He is an experienced networking engineer with practical experience working for the largest networks in the world at such companies as Xerox, Hughes Aircraft, Texaco, AAA, Cisco, and Toshiba, among others. Todd has published over 60 books, including the best-selling CCNA Study Guide. You can reach Todd at www.lammle.com.

Introduction xi Chapter 1 Basic IOS Commands 1 Booting the Router 2 Setup Mode 4 Router Configuration Modes 4 Editing and Help Features 6 Configuring a Router 8 Hostnames 9 Banners 9 Passwords 10 Router Interfaces 14 Viewing, Saving, and Erasing Configurations 18 Using the show Command 19 Troubleshooting with the show interfaces Command 22 Chapter 2 Managing a Cisco Internetwork 25 Understanding the Internal Components of a Cisco Router 26 Managing the Configuration Register 27 Checking the Current Configuration Register Value 27 Changing the Configuration Register 28 Recovering Passwords 30 Using Boot System Commands 32 Backing Up and Restoring the Cisco IOS 33 Verifying Flash Memory 33 Backing Up the Cisco IOS 34 Restoring or Upgrading the Cisco Router IOS 36 Using the Cisco IOS File System (Cisco IFS) 36 Backing Up and Restoring the Cisco Configuration 39 Backing Up the Cisco Router Configuration 39 Restoring the Cisco Router Configuration 41 Erasing the Configuration 41 Using the Cisco IOS File System to Manage Your Router's Configuration (Cisco IFS) 42 Using Cisco Discovery Protocol (CDP) 43 Getting CDP Timers and Holdtime Information 44 Gathering Neighbor Information 45 Gathering Interface Traffic Information 47 Gathering Port and Interface Information 47 Using Telnet 48 Telnetting into Multiple Devices Simultaneously 49 Checking Telnet Connections 50 Checking Telnet Users 50 Closing Telnet Sessions 51 Resolving Hostnames 52 Building a Host Table 52 Using DNS to Resolve Names 54 Checking Network Connectivity and Troubleshooting 55 Using the ping Command 56 Using the traceroute Command 56 Debugging 57 Using the sh processes Command 59 Chapter 3 IP Routing 61 Routing Basics 62 Static Routing 65 Default Routing 67 Routing Protocol Basics 69 Administrative Distances (ADs) 69 Routing Information Protocol (RIP) 70 RIP Timers 71 Enabling RIP 72 Holding Down RIP Propagations 73 RIP Version 2 (RIPv2) 73 Verifying RIP 75 The show ip protocols Command 75 The debug ip rip Command 76 Chapter 4 Enhanced IGRP (EIGRP) and Open Shortest Path First (OSPF) 79 Understanding EIGRP Basics 80 Configuring EIGRP 80 Holding Down EIGRP Propagations 81 Setting Maximum Paths and Hop Count 82 Using Redistribution Commands 83 Configuring Discontiguous Networks 84 Load Balancing with EIGRP 85 Using Route Authentication with EIGRP 89 Verifying EIGRP 90 Understanding Open Shortest Path First (OSPF) Basics 94 Configuring OSPF 95 Enabling OSPF 95 Configuring OSPF Areas 96 Verifying OSPF Configuration 96 Using the show ip ospf Command 98 Using the show ip ospf database Command 99 Using the show ip ospf interface Command 99 Using the show ip ospf neighbor Command 100 Using the show ip protocols Command 101 Debugging OSPF 102 Chapter 5 Layer-2 Switching and Spanning-Tree Protocol (STP) 105 Switching Services 106 Three Switch Functions at Layer 2 107 Basic Switch Configurations 108 Switch Security 109 Spanning-Tree Operations 111 Optimizing Spanning-Tree Operations 113 EtherChannel 117 Verifying Cisco Catalyst Switches 119 Chapter 6 Virtual LANs (VLANs) 127 Understanding VLAN Basics 128 Configuring VLANs 128 Verifying VLAN Creation 130 Assigning Switch Ports to VLANs 130 Configuring Trunk Ports 132 Configuring Inter-VLAN Routing 136 Configuring VTP 137 Telephony: Configuring Voice VLANs 139 Configuring the Voice VLAN 140 Chapter 7 Security 143 Perimeter Routers, Firewalls, and Internal Routers 144 Recognizing Security Threats 144 Using Cisco IOS Firewall 146 Introduction to Access Lists 147 Standard Access Lists 148 Wildcard Masking 150 Controlling VTY (Telnet) Access 151 Extended Access Lists 151 Named Access Lists 157 Switch Port ACLs 159 Time-Based ACLs 161 Monitoring Access Lists 163 Chapter 8 Network Address Translation (NAT) 167 When Do We Use NAT? 168 Types of Network Address Translation 169 NAT Names 170 Static NAT Configuration 171 Dynamic NAT Configuration 172 PAT (Overloading) Configuration 173 Simple Verification of NAT 174 Chapter 9 Internet Protocol Version 6 (IPv6) 177 Why Do We Need IPv6? 178 IPv6 Addressing and Expressions 179 Shortened Expression 180 Configuring Cisco Routers with IPv6 181 Stateless Auto Configuration 182 IPv6 Static Routing 182 IPv6 Routing Protocols 183 RIPng 183 EIGRPv6 184 OSPFv3 185 Verifying RIPng 187 Verifying EIGRPv6 190 Verifying OSPFv3 191 Chapter 10 Wide Area Networks (WANs) 195 Introduction to Wide Area Networks 196 Defining WAN Terms 197 WAN Support 197 Point-to-Point Serial Links 200 High-Level Data-Link Control (HDLC) Protocol 201 Point-to-Point Protocol (PPP) 202 Configuring PPP on Cisco Routers 203 Configuring PPP Authentication 204 Verifying PPP Encapsulation 205 Introduction to Frame Relay Technology 210 Frame Relay Encapsulation Types 211 Data Link Connection Identifiers (DLCIs) 212 Local Management Interface (LMI) 213 Frame Relay Implementation and Monitoring 216 GRE Tunnels 225 Verifying a GRE Tunnel 226 Chapter 11 IP Services 227 Network Monitoring and Management Services 228 Simple Network Management Protocol (SNMP) 228 Syslog 230 First Hop Redundancy and Load Balancing 231 Hot Standby Routing Protocol (HSRP) 232 Gateway Load Balancing Protocol (GLBP) 234 Index 237