Introduction... 1 Book I: Overview... 5

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1 Contents at a Glance Introduction... 1 Book I: Overview... 5 Chapter 1: Looking at the Cisco Network World...7 Chapter 2: Exploring Cisco Network Design...23 Chapter 3: Knowing as Little as Possible about Math...47 Chapter 4: Testing Your Core Networking Knowledge...59 Chapter 5: Getting into the Cisco Internetwork Operating System...95 Book II: Internet Protocols Chapter 1: Making the Most of IPv Chapter 2: Choosing between Protocols: TCP and UDP Chapter 3: Working with ARP, the IP Communication Model, and Data Link Layer Troubleshooting Chapter 4: Preparing for the Advent of IPv Book III: Switching Chapter 1: Reviewing the Enterprise LAN Chapter 2: Switching Basics Chapter 3: Configuring Switches Chapter 4: Easing Device Discovery with CDP Chapter 5: Virtualizing Networks with VLANs and VTP Chapter 6: Adding Fault Tolerance with STP Chapter 7: Adding Fault Tolerance with EtherChannel Chapter 8: Speeding Configuration with Smartport Macros COPYRIGHTED MATERIAL Book IV: Routing Chapter 1: Making the Wide Area Network (WAN) Wide Chapter 2: Cozying Up to Routing Basics Chapter 3: Router Configuration Chapter 4: Setting Up Static Routes Chapter 5: Configuring Serial Connections and WAN Links Chapter 6: Meeting the Routing Protocols Chapter 7: Checking Out RIP and EIGRP Characteristics and Design Chapter 8: Getting Comfortable with the OSPF and IS-IS Protocols Chapter 9: Routing with BGP and IP Multicast...451

2 Book V: Wireless Chapter 1: Getting Wise to Wireless LANs Chapter 2: Planning Your WLAN Chapter 3: Securing Your WLAN Chapter 4: Building a Cisco Wireless Network Book VI: Security Chapter 1: Defending against Common Attacks with Basic Security Tools Chapter 2: Securing Networks with Cisco s Adaptive Security Appliance Chapter 3: Securing Networks with ACLs and NAT Chapter 4: Cisco Security Best Practices Index

3 Table of Contents Introduction... 1 About This Book...1 Conventions Used in This Book...1 Foolish Assumptions...2 How This Book Is Organized...2 Book I: Overview...2 Book II: Internet Protocols...2 Book III: Switching...2 Book IV: Routing...3 Book V: Wireless...3 Book VI: Security...3 Icons Used in This Book...3 Where to Go from Here...4 Book I: Overview... 5 Chapter 1: Looking at the Cisco Network World Glazing Over the OSI Network Layer Model...8 Connecting with Switches...13 Moving On Up with Routers...14 Taking the Network Wireless...15 Securing Data with Firewalls...16 Adding a Network Voice (Over IP, That Is)...17 Focusing on Small Business Networks...19 Taking Cisco Products Home...20 Chapter 2: Exploring Cisco Network Design Embracing Methodologies...23 Intelligent Information Network (IIN)...24 Service-Oriented Network Architecture (SONA)...25 Prepare, Plan, Design, Implement, Operate, and Optimize (PPDIOO)...28 Examining the Layered Network Model...37 Core layer...39 Distribution layer...40 Access layer...42 Enterprise modules...44

4 xii Cisco Networking All-in-One For Dummies Chapter 3: Knowing as Little as Possible about Math Why These Number Systems Are Important...48 Working with Bits and Bytes...50 Pondering the Significance of the Significant Bit...52 Making Conversions...52 Converting Base 2 (binary) to Base 10 (decimal)...53 Converting binary to Base 8 (octal)...55 Converting binary to Base 16 (hexadecimal)...56 Chapter 4: Testing Your Core Networking Knowledge Layering the OSI Model...60 Layer 1: The physical layer...61 Layer 2: The data link layer...62 Layer 3: The network layer...63 Layer 4: The transport layer...65 Layer 5: The session layer...66 Layer 6: The presentation layer...68 Layer 7: The application layer...70 Troubleshooting by Layers...72 Troubleshooting the physical layer...72 Troubleshooting the data link layer...73 Troubleshooting network and transport layers...73 Troubleshooting the application layer...74 Framing Data...75 Figuring Out Packets...77 Looking at packets...78 Viewing packet structure...79 Getting the Lowdown on Low-Level and High-Level Addressing...80 Taking control of MAC addresses...80 Structuring the IP address...82 Reviewing Internetwork Packet Exchange...82 Getting the basics with NetBIOS Extended User Interface...83 Watching the Traffic Go By...83 CSMA/CD...83 CSMA/CA...84 Choosing CSMA/CD or CSMA/CA...86 Sharking the Network Data...87 Capture options...91 Filtering captured data...92 Chapter 5: Getting into the Cisco Internetwork Operating System...95 Working with the Internetwork Operating System...95 Checking out the show command...96 Understanding operating modes Getting going with the command line...107

5 Table of Contents xiii Tinkering with Device Connections Connecting directly via a Cisco rollover cable Connecting remotely via Telnet or SSH Graphical configuration interfaces Upgrading Firmware and Booting an IOS Image Upgrading the IOS image Managing the boot process Book II: Internet Protocols Chapter 1: Making the Most of IPv Meeting TCP/IP, Belle of the Networking Ball Comparing TCP/IP with the OSI Network Model Comprehending the Structure of an IP Address Knowing Your Network Classes Class A Class B Class C Class D Class E Public, private, and automatic IP addresses Examining special IP addresses Breaking Up Networks with Subnetting Subnetting Mulling the number of hosts Modifying the subnet mask Explaining Classless InterDomain Routing (CIDR) CIDR notation Variable Length Subnet Masks (VLSM) Supernetting ( ) route summarization Chapter 2: Choosing between Protocols: TCP and UDP Understanding the UDP and TCP Structure Examining packet structure TCP and UDP header structures Sockets and ports Checking out which services use which ports Knowing When to Use TCP Services that use TCP Three-way handshaking Sliding windows Knowing When to Use UDP...175

6 xiv Cisco Networking All-in-One For Dummies Chapter 3: Working with ARP, the IP Communication Model, and Data Link Layer Troubleshooting Watching Address Resolution Protocol in Action The logical AND Using ARP Troubleshooting with ARP Checking out arp command options Looking through your ARP cache with arp -a Adding a static ARP entry Seeing how ARP is useful Using Other Troubleshooting Tools ping traceroute/tracert PathPing Chapter 4: Preparing for the Advent of IPv Reviewing Address Structure Collapsing Addresses Identifying Special Addresses Assigning Addresses Integration with IPv Book III: Switching Chapter 1: Reviewing the Enterprise LAN Identifying Features of an Enterprise LAN Working with Cisco Switching Technologies Small-to-medium business products Classical enterprise products Reviewing Switching Standards Purchasing Support Chapter 2: Switching Basics Switching and the OSI Model Communicating with Duplex/Simplex Colliding and Broadcasting Powering Up Your Switch Viewing status lights Connecting the client cables Chapter 3: Configuring Switches Switching with the Internetwork Operating System (IOS) Connecting to Your Switch...238

7 Table of Contents xv Revealing Basic Switch Configuration Setting a hostname Examining ports and speeds Configuring interfaces Configuring the management interface Setting the default gateway Setting passwords Working with Users Creating a user in the account database Removing a user Enable user-level protection Running Setup Wizard Working with Web Console Dashboard Configure Monitor Maintenance Network Assistant Chapter 4: Easing Device Discovery with CDP Discovering How CDP Operates Working with CDP Seeing whether CDP is operating on a device Enabling CDP Disabling CDP Viewing information about devices Checking traffic data Ogling CDP s debug options Overlooking CDP miscellany Building Your Network Layout Chapter 5: Virtualizing Networks with VLANs and VTP Implementing Virtual Local Area Networks (VLANs) Understanding how VLANs work Setting up VLANs Configuring a range of interfaces VLAN database Getting Started with VLAN Trunking Protocol (VTP) Learning how VTP works Implementing VTP Being leery of the VTP configuration revision number Pruning in the VTP tree Configuring VTP Viewing your VTP settings...292

8 xvi Cisco Networking All-in-One For Dummies Chapter 6: Adding Fault Tolerance with STP Working with Spanning Tree Protocol (STP) Building the initial topology Dealing with network changes Setting Up STP STP and issues with VLANs STP and PortFast Troubleshooting STP Debugging STP Chapter 7: Adding Fault Tolerance with EtherChannel Examining How EtherChannel Works Checking Out EtherChannel Basic Guidelines Setting Up EtherChannel Stepping through EtherChannel configuration Configuring EtherChannel load balancing Getting at Diagnostic Information for EtherChannel Debugging EtherChannel Chapter 8: Speeding Configuration with Smartport Macros Viewing Existing Smartport Macros Viewing macros using the brief option Viewing macros without the brief option Viewing details for a single macro Working with Macros Rules for creating your own Smartport macro Smartport macros and parameters Creating a sample macro Applying a Smartport macro to an interface Viewing ports that are using your macro Removing a macro Book IV: Routing Chapter 1: Making the Wide Area Network (WAN) Wide Identifying Features of a WAN Sending data long distances Implementing routing protocols Using carrier equipment Getting a handle on network size Choosing Technologies Getting the physical connection Choosing a routing protocol...345

9 Table of Contents xvii Chapter 2: Cozying Up to Routing Basics Of Routers and Routing Knowing why routers are useful Knowing what routers do Examining the routing process Viewing your router s routing table Enabling Routing Working with DHCP Setting up your DHCP server Watching the DHCP traffic go by Getting DHCP help from the IP Helper Automatic Private IP Addressing (APIPA) Chapter 3: Router Configuration Getting to Know the Internetwork Operating System (IOS) for Routers Making Router Connections Performing a Basic Configuration Setting the hostname Configuring standard router ports Configuring interfaces Configuring your router s IP settings Enabling routing Configuring passwords Setting banners Running Setup Wizard Working with Users Creating a user in the account database Removing a user Enable user-level protection Showing connected users Chapter 4: Setting Up Static Routes Knowing the Pros and Cons of Static Routing Building a Small Network with Static Routing Getting network info from your router Configuring the second router Adding a third router Running around and around with routing loops Chapter 5: Configuring Serial Connections and WAN Links Finding Out Where the Telephone Company Fits In Circuit switching Leased lines Packet switching...397

10 xviii Cisco Networking All-in-One For Dummies Connecting Your Devices Serial ports Integrated CSU/DSU ISDN ports Setting Up Your Serial Connection Configuring your serial connection Configuring serial link protocols Setting the clock rate Troubleshooting Serial Connections Showing Debugging Chapter 6: Meeting the Routing Protocols Checking Out Criteria for Routing Protocol Selection Classifying by where protocols are used Classifying by how protocols calculate routing Administrative distance Introducing the Protocols Distance-Vector Routing Examining basic function of distance-vector routing Count to infinity and routing loops Preventing count to infinity issues Link-State Routing Understanding link-state protocol Working with your strengths Chapter 7: Checking Out RIP and EIGRP Characteristics and Design Working with Routing Information Protocol (RIP) Understanding the RIP commands Troubleshooting RIP Working with Enhanced Interior Gateway Routing Protocol (EIGRP) Using the EIGRP commands Troubleshooting EIGRP Chapter 8: Getting Comfortable with the OSPF and IS-IS Protocols Open Shortest Path First (OSPF) Getting comfortable with OSPF basics Configuring OSPF Working with wildcard masks Keeping track of router IDs Troubleshooting OSPF Debugging OSPF Intermediate System to Intermediate System (IS-IS) Enabling IS-IS routing Checking that IS-IS is running Troubleshooting the IS-IS protocol...449

11 Table of Contents xix Chapter 9: Routing with BGP and IP Multicast Routing with Border Gateway Protocol (BGP) Routing via weights Understanding BGP commands Viewing routes in your routing table Viewing how the protocol is functioning Troubleshooting BGP Routing IP Multicast Traffic Knowing when to use multicast routing Getting to know the protocols Configuring multicast routing Troubleshooting multicast routing Book V: Wireless Chapter 1: Getting Wise to Wireless LANs Understanding the Benefit of Wireless LANs Learning the Wireless Technologies Following the Standards Licensed radio bands Unlicensed radio bands Sending Data Over the Airwaves Understanding signals Modulating signals Introducing RF modulation techniques Battle of the Bands Checkin Out the 2.4-GHz band Keep on Rockin with the 5-GHz band Technologies that support the 2.4-GHz and 5-GHz bands Chapter 2: Planning Your WLAN Setting Your Operation Mode Ad Hoc mode Infrastructure mode Grouping Your Clients with SSID SSID basics Using multiple SSIDs with a single AP Basic service set (BSS) Extended service set (ESS) Planning Around Interference RF signal factors Conducting a site survey Working with Multiple APs Selecting channels AP layout Automatic tuning...518

12 xx Cisco Networking All-in-One For Dummies Chapter 3: Securing Your WLAN Understanding the Benefits of a Secure WLAN Finding balance between functionality and security Recognizing security risks Checking Out Security Risk Mitigation Methods Authentication and data encryption Filtering the MAC address Hiding the service set identifier (SSID) Intrusion detection and prevention Isolating users with VLANs Securing the Management Interface Changing default passwords Getting even more secure with SSH, SSL, TLS, HTTPS Management access Isolating the entire WLAN Chapter 4: Building a Cisco Wireless Network Introducing the Cisco Unified Wireless Networks Architecture (CUWN) Keeping it simple with Wireless LAN Controllers Going mobile with Cisco WLAN access point (AP) devices Cisco Wireless Control System (WCS) Lightweight Access Point Protocol (LWAPP) Setting Up Your Wireless LAN Setting up and verifying the wired LAN to which the WLAN will connect Setting up the Cisco Wireless LAN Controller(s) Configuring WLAN security Configuring WEP keys Setting up Cisco access points Configuring backup controllers Web authentication process Using the Cisco graphical user interface (GUI) Book VI: Security Chapter 1: Defending against Common Attacks with Basic Security Tools Knowing Your Enemy Handling attacks from within Dealing with external attacks Implementing Firewalls Types of firewalls Ingress and egress filtering Defending data with the DMZ...568

13 Table of Contents xxi Defending Your Network against Attacks Perimeter defense Active tools Defense in depth Security Tools Personal firewalls Antivirus software Anti-malware Spam filters Intrusion detection Vulnerability scanners User common sense Chapter 2: Securing Networks with Cisco s Adaptive Security Appliance Locating Firewalls in the OSI Model Getting to Know the Internetwork Operating System Making Connections Running the ASA Setup Wizard Performing a Basic Configuration Device name Standard firewall ports Interfaces IP addresses Security zones Passwords Banners Setting Up User Accounts Configuring Dynamic Host Configuration Protocol Examining Your License Chapter 3: Securing Networks with ACLs and NAT Securing Networks with ACLs Creating ACLs Standard ACLs Extended ACLs Applying an ACL Using ACLs as a Virus Detection Tool Where You Can Use ACLs Setting up Network Address Translation Requirements for NAT Types of NAT Setting up NAT Viewing translations...631

14 xxii Cisco Networking All-in-One For Dummies Chapter 4: Cisco Security Best Practices Management Areas Finding Out About Known Issues with Cisco Devices Leveraging Authentication, Authorization, and Accounting Authentication fallback Avoiding Type 7 passwords Centralizing Log Collection and Monitoring Collecting logs in one location Choosing a logging level Dealing with logging in the console, monitor, and buffer Implementing Secure Protocols Managing Configurations Password management Managing services Setting up timeouts Keeping alive TCP Leaving room for management Securing SNMP Replacing and rolling back Taking the talking stick with terminal lock Using logs to tell you what is going on Managing network features Getting Physical with Security Index