Cisco Networking All-in-One For Dummies. 2 Ed

Title Page....5 Copyright Page....6 Table of Contents....9 Introduction....23 About This Book....23 Conventions Used in This Book....23 Foolish Assumptions....24 How This Book Is Organized....24 Book 1: Overview....25 Book 2: Internet Protocols....25 Book 3: Switching....25 Book 4: Routing....25 Book 5: Wireless....25 Book 6: Security....25 Icons Used in This Book....26 Where to Go from Here....26 Book 1 Overview....29 Chapter 1 Looking at the Cisco Network World....31 Glazing Over the OSI Network Layer Model....32 Connecting with Switches....37 Moving On Up with Routers....38 Taking the Network Wireless....39 Securing Data with Firewalls....40 Adding a Network Voice (Over IP, That Is)....41 Focusing on Small Business Networks....43 Chapter 2 Exploring Cisco Network Design....45 Embracing Methodologies....46 Intelligent Information Network (IIN)....47 Service-Oriented Network Architecture (SONA)....48 Prepare, Plan, Design, Implement, Operate, and Optimize (PPDIOO)....51 Prepare....51 Plan....53 Design....57 Implement....58 Operate....60 Optimize....60 Examining the Layered Network Model....61 Core layer....62 Distribution layer....63 Access layer....65 Enterprise modules....68 Enterprise Campus....69 Enterprise Edge modules....69 Service Provider Edge modules....69 Remote modules....70 Recent Cisco infrastructure focus....70 AI-ready infrastructure and AgenticOps....70 Unified management....71 Zero Trust and secure edge....71 Intent-based Networking (IBN)....71 Distributed Policy Enforcement....72 Chapter 3 Knowing as Little as Possible about Math....73 Why These Number Systems Are Important....74 Working with Bits and Bytes....76 Pondering the Significance of the Significant Bit....78 Making Conversions....78 Converting Base 2 (binary) to Base 10 (decimal)....79 Converting binary to Base 8 (octal)....82 Converting binary to Base 16 (hexadecimal)....83 Chapter 4 Testing Your Core Networking Knowledge....87 Layering the OSI Model....88 Layer 1: The physical layer....89 Layer 2: The data link layer....90 Layer 3: The network layer....91 Layer 4: The transport layer....93 Layer 5: The session layer....94 Layer 6: The presentation layer....96 Layer 7: The application layer....98 Troubleshooting by Layers....100 Troubleshooting the physical layer....101 Troubleshooting the data link layer....101 Troubleshooting network and transport layers....102 Troubleshooting the application layer....103 Framing Data....104 Figuring Out Packets....106 Looking at packets....106 Viewing packet structure....107 Getting the Lowdown on Low-Level and High-Level Addressing....108 Taking control of MAC addresses....108 Structuring the IP address....110 Reviewing Internetwork Packet Exchange....111 Getting the basics with NetBIOS Extended User Interface....111 Watching the Traffic Go By....112 CSMACD....112 CSMACA....114 Choosing CSMACD or CSMACA....114 Sharking the Network Data....115 Capture options....120 Saving captured data....121 Chapter 5 Getting into the Cisco Internetwork Operating System....125 Working with the Internetwork Operating System....126 Checking out the show command....126 Examining show version on a switch....127 Examining show version on a router....130 Examining show version on the Cisco ASA firewall....131 Understanding operating modes....134 User EXEC mode....134 Privileged EXEC mode....136 Global Configuration mode....137 Interface Configuration Mode....138 Saving your work....140 Getting going with the command line....141 Getting a commands options....142 Autocomplete....142 Using the command buffer....143 Tinkering with Device Connections....143 Connecting directly via a Cisco rollover cable....144 Connecting remotely via Telnet or SSH....149 Telnet....149 Secure Shell (SSH)....149 Graphical configuration interfaces....151 Small Business devices....151 Enterprise devices....152 Upgrading Firmware and Booting an IOS Image....155 Upgrading the IOS image....156 Managing the boot process....158 Recovering a Cisco device....158 Choosing a boot image....161 Recovering a device with a lost password....162 Book 2 Internet Protocols....165 Chapter 1 Making the Most of IPv4....167 Meeting TCPIP, Belle of the Networking Ball....168 Comparing TCPIP with the OSI Network Model....169 Comprehending the Structure of an IP Address....170 Knowing Your Network Classes....171 Class A....171 Class B....172 Class C....172 Class D....172 Class E....173 Public, private, and automatic IP addresses....174 Examining special IP addresses....176 Breaking Up Networks with Subnetting....178 Subnetting 101....178 Mulling the number of hosts....179 Modifying the subnet mask....180 Class A subnetting....182 Class B subnetting....183 Class C subnetting....183 Explaining Classless InterDomain Routing (CIDR)....185 CIDR notation....186 Variable Length Subnet Masks (VLSM)....187 Supernetting....189 Chapter 2 Choosing between Protocols: TCP and UDP....193 Understanding the UDP and TCP Structure....194 Examining packet structure....194 TCP and UDP header structures....198 TCP headers....198 UDP header....200 Sockets and ports....201 Checking out which services use which ports....203 Knowing When to Use TCP....204 Services that use TCP....204 Three-way handshaking....205 Sliding windows....206 Knowing When to Use UDP....209 Chapter 3 Working with ARP, the IP Communication Model, and Data Link Layer Troubleshooting....211 Watching Address Resolution Protocol in Action....212 The logical AND....213 Using ARP....216 ARP requests for local hosts....218 ARP requests for remote hosts....221 Troubleshooting with ARP....223 Checking out ARP command options....224 Looking through your ARP cache with arp -a....224 Adding a static ARP entry....225 Seeing how ARP is useful....228 Using Other Troubleshooting Tools....228 ping....229 traceroutetracert....234 PathPing....236 Chapter 4 Working with IPv6....239 Reviewing Address Structure....240 Collapsing Addresses....241 Identifying Special Addresses....242 Assigning Addresses....244 Integration with IPv4....245 Book 3 Switching....249 Chapter 1 Reviewing the Enterprise LAN....251 Identifying Features of an Enterprise LAN....252 Working with Cisco Switching Technologies....253 Small-to-medium business products....254 Classical enterprise products....255 Reviewing Switching Standards....256 Purchasing Support....260 Cisco SMARTnet Total Care (SNTC) Support....260 CX Cloud....261 Chapter 2 Switching Basics....263 Switching and the OSI Model....264 Communicating with DuplexSimplex....265 Colliding and Broadcasting....266 Powering Up Your Switch....268 Viewing status lights....268 Connecting the client cables....273 Chapter 3 Configuring Switches....277 Switching with the Internetwork Operating System (IOS)....277 Connecting to Your Switch....278 Revealing Basic Switch Configuration....280 Setting a hostname....280 Examining ports and speeds....280 Configuring interfaces....281 Configuring the management interface....283 Setting the default gateway....286 Setting passwords....287 Setting the enable password....287 Setting the Telnet password....288 Setting the SSH password....290 Setting the console port password....291 Knowing where passwords sleep....292 Banners....292 Working with Users....294 Creating a user in the account database....294 Removing a user....295 Enable user-level protection....295 Running Setup Wizard....295 Working with Web Console....299 Dashboard....299 Configure....300 Smartports....300 Port Settings....304 Restart and Reset....304 Monitor....304 Trends....305 Port Status....305 Port Statistics....305 Maintenance....305 Network Assistant....306 Chapter 4 Easing Device Discovery with CDP....307 Discovering How CDP Operates....308 Working with CDP....309 Seeing whether CDP is operating on a device....309 Enabling CDP....310 Disabling CDP....310 Viewing information about devices....311 Checking traffic data....314 Overlooking CDP miscellany....314 Building Your Network Layout....315 Chapter 5 Virtualizing Networks with VLANs and VTP....319 Implementing Virtual Local Area Networks (VLANs)....320 Understanding how VLANs work....321 Haggling with gargantuan packet sizes....322 VLAN frames....322 Passing traffic from VLAN to VLAN....323 Setting up VLANs....324 Configuring a range of interfaces....326 VLAN database....327 Getting Started with VLAN Trunking Protocol (VTP)....328 Learning how VTP works....329 Implementing VTP....330 Being leery of the VTP configuration revision number....330 Pruning in the VTP tree....331 Configuring VTP....333 Viewing your VTP settings....335 Chapter 6 Adding Fault Tolerance with STP....337 Working with Spanning Tree Protocol (STP)....338 Building the initial topology....338 Identifying Root Ports....339 Identifying Designated Ports....340 Blocking loops....341 Dealing with network changes....342 Setting Up STP....346 STP and issues with VLANs....347 STP and PortFast....348 Setting PortFast on all ports....349 Setting PortFast on specific ports....350 Troubleshooting STP....351 Debugging STP....354 Chapter 7 Adding Fault Tolerance with EtherChannel....359 Examining How EtherChannel Works....360 Checking Out EtherChannel Basic Guidelines....363 Setting Up EtherChannel....364 Stepping through EtherChannel configuration....365 Configuring EtherChannel load balancing....367 Getting at Diagnostic Information for EtherChannel....368 Debugging EtherChannel....370 Chapter 8 Speeding Configuration with Smartport Macros....373 Viewing Existing Smartport Macros....374 Viewing macros using the brief option....374 Viewing macros without the brief option....374 Viewing details for a single macro....378 Working with Macros....379 Rules for creating your own Smartport macro....379 Smartport macros and parameters....380 Creating a sample macro....380 Applying a Smartport macro to an interface....381 Enabling Auto Smartport macros....382 Viewing ports that are using your macro....384 Removing a macro....385 Book 4 Routing....387 Chapter 1 Making the Wide Area Network (WAN) Wide....389 Identifying Features of a WAN....389 Sending data long distances....390 Implementing routing protocols....390 Using carrier equipment....390 Getting a handle on network size....391 CANs....391 MANs....393 WANs....393 Choosing Technologies....393 Getting the physical connection....393 Choosing a routing protocol....395 Routing Information Protocol (RIP)....396 Enhanced Interior Gateway Routing Protocol (EIGRP)....398 Open Shortest Path First (OSPF)....399 Intermediate System to Intermediate System (IS-IS)....400 Border Gateway Protocol (BGP)....400 Chapter 2 Cozying Up to Routing Basics....401 Of Routers and Routing....401 Knowing why routers are useful....402 Knowing what routers do....403 Examining the routing process....404 Viewing your routers routing table....405 Enabling Routing....406 Working with DHCP....407 Setting up your DHCP server....409 Watching the DHCP traffic go by....412 Getting DHCP help from the IP Helper....414 Automatic Private IP Addressing (APIPA)....415 Chapter 3 Router Configuration....417 Getting to Know the Internetwork Operating System (IOS) for Routers....417 Making Router Connections....418 Performing a Basic Configuration....418 Setting the hostname....419 Configuring standard router ports....419 Configuring interfaces....420 Connecting to your router....421 Using auto settings....421 Adding a description....422 Configuring a VLAN identifier....422 Setting a routing interface....422 Enabling your interface....422 Double-checking your settings....423 Configuring your routers IP settings....424 Enabling routing....425 Configuring passwords....426 Setting the enable password....427 Setting the secret password....427 Setting the Telnet password....428 Setting the SSH password....429 Setting the console port password....431 Setting the Auxiliary Port (AUX) password....431 Finding out where passwords live....432 Setting banners....433 Running Setup Wizard....434 Working with Users....436 Creating a user in the account database....437 Removing a user....437 Enable user-level protection....437 Showing connected users....438 Chapter 4 Setting Up Static Routes....439 Knowing the Pros and Cons of Static Routing....440 Building a Small Network with Static Routing....441 Getting network info from your router....441 Configuring the second router....442 Adding a third router....447 Running around and around with routing loops....448 Crossing VLANs with Routed Traffic....450 Passing Traffic in the Switch....450 Routing Back and Forth....452 Chapter 5 Configuring Serial Connections and WAN Links....455 Finding Out Where the Telephone Company Fits In....456 Circuit switching....457 Leased lines....457 Packet switching....458 Connecting Your Devices....459 Serial ports....459 Integrated CSUDSU....461 ISDN ports....461 Setting Up Your Serial Connection....461 Configuring your serial connection....461 Configuring serial link protocols....462 Working with HDLC....462 Working with PPP....462 Setting the clock rate....463 Troubleshooting Serial Connections....464 Showing....464 Debugging....466 Chapter 6 Meeting the Routing Protocols....469 Checking Out Criteria for Routing Protocol Selection....470 Classifying by where protocols are used....470 Classifying by how protocols calculate routing....470 Distance-vector protocols....470 Link-state protocols....471 Other types of protocols....471 Administrative distance....471 Introducing the Protocols....472 Distance-Vector Routing....473 Examining basic function of distance-vector routing....474 Count to infinity and routing loops....475 Preventing count to infinity issues....477 Split horizon....477 Route poisoning....478 Hold-down timers....479 Triggered updates....479 Link-State Routing....480 Understanding link-state protocol....480 Working with your strengths....480 Chapter 7 Checking Out RIP and EIGRP Characteristics and Design....483 Working with Routing Information Protocol (RIP)....484 Understanding the RIP commands....484 Enabling RIP....484 Showing routes coming from a specific routing protocol....486 Configuring your RIP version....486 Troubleshooting RIP....488 Getting network information....488 Seeing information RIP receives....490 Debugging RIP....490 Working with Enhanced Interior Gateway Routing Protocol (EIGRP)....491 Using the EIGRP commands....491 Auto-summary....492 Split horizon....493 Load balancing....494 Clearing your IP route....496 Troubleshooting EIGRP....496 The interfaces option....497 The neighbors option....497 The topology option....498 The traffic option....498 The debug command....499 Chapter 8 Getting Comfortable with the OSPF and IS-IS Protocols....501 Open Shortest Path First (OSPF)....502 Getting comfortable with OSPF basics....502 OSPF as a link-state protocol....502 OSPF packet types....503 Knowing areas and Autonomous Systems....504 The Hello packet....505 Checking out the base cost....505 Configuring OSPF....506 Working with wildcard masks....508 Keeping track of router IDs....509 Troubleshooting OSPF....511 Viewing routes in the routing table....511 Viewing your IP protocols....512 Viewing options for the show ip ospf command....513 Viewing information about interfaces....514 Viewing detailed info about neighbors....515 Debugging OSPF....515 Viewing events....516 Intermediate System to Intermediate System (IS-IS)....517 Enabling IS-IS routing....517 Checking that IS-IS is running....519 Troubleshooting the IS-IS protocol....520 Viewing the show options....520 Looking at debug options....521 Chapter 9 Routing with BGP and IP Multicast....523 Routing with Border Gateway Protocol (BGP)....523 Routing via weights....524 Understanding BGP commands....525 Viewing routes in your routing table....526 Viewing how the protocol is functioning....526 Troubleshooting BGP....527 BGP show commands....528 BGP debug commands....530 Routing IP Multicast Traffic....532 Knowing when to use multicast routing....532 Getting to know the protocols....532 Working with IGMP....533 Getting into PIM....534 Managing MLD....536 Configuring multicast routing....536 Enabling multicast routing....536 Supporting Sparse-Dense mode....536 Using Auto-RP rather than RPs....537 Testing connectivity....537 Troubleshooting multicast routing....538 Getting information with show....538 Debugging multicast routing....541 Book 5 Wireless....545 Chapter 1 Getting Wise to Wireless LANs....547 Understanding the Benefit of Wireless LANs....548 Learning the Wireless Technologies....548 Following the Standards....549 Licensed radio bands....549 Unlicensed radio bands....550 Sending Data Over the Airwaves....552 Understanding signals....552 Modulating signals....553 Introducing RF modulation techniques....555 Frequency-hopping spread spectrum (FHSS)....555 Direct-sequence spread spectrum (DSSS)....555 Orthogonal frequency division multiplexing (OFDM)....556 Multiple-in, multiple-out (MIMO)....556 Battle of the Bands....557 Checkin out the 2.4-GHz band....557 IEEE 802.11....558 IEEE 802.11b (also called Wi-Fi 2)....562 IEEE 802.11g (Wi-Fi 3) and beyond....562 Keep on Rockin with the 5-GHz band....563 Moving on with 6-GHz....564 Technologies that support the 2.4-GHz, 5-GHz, and 6-GHz bands....564 Chapter 2 Planning Your WLAN....565 Setting Your Operation Mode....565 Ad Hoc mode....566 Understanding Ad Hoc mode networking....566 Configuring an Ad Hoc mode WLAN....567 Configuring a Mobile Hotspot WLAN with Windows 11....568 Configuring Nearby Sharing with Windows 11....569 Infrastructure mode....572 Connecting to a wireless network in Windows 11....573 Enterprise infrastructure access point types....574 Grouping Your Clients with SSID....576 SSID basics....576 Using multiple SSIDs with a single AP....577 Basic service set (BSS)....578 Extended service set (ESS)....578 Planning Around Interference....579 RF signal factors....579 Conducting a site survey....580 Working with Multiple APs....583 Selecting channels....583 AP layout....584 Automatic tuning....587 Chapter 3 Securing Your WLAN....589 Understanding the Benefits of a Secure WLAN....590 Finding balance between functionality and security....590 Recognizing security risks....590 Checking Out Security Risk Mitigation Methods....591 Authentication and data encryption....592 Reviewing WEP....592 Getting serious with WPA....594 Getting even more serious with WPA2....595 Getting the most serious with WPA3....596 Filtering the MAC address....597 Hiding the service set identifier (SSID)....597 Intrusion detection and prevention....598 Isolating users with VLANs....598 Securing the Management Interface....601 Changing default passwords....601 Getting even more secure with SSH, SSL, TLS, HTTPS....602 Management access....603 Isolating the entire WLAN....603 Chapter 4 Building a Cisco Wireless Network....605 Introducing the Cisco Catalyst Wireless Network Solution....606 Modern Wireless Controllers....606 Legacy Wireless LAN Controller equipment....607 Common Wireless Controller features....607 Controller features with LWAPPCAPWAP....608 Setting Up Your Wireless LAN....610 Setting up and verifying the wired LAN to which the WLAN will connect....610 Setting up the modern Catalyst Wireless Controller....610 Initial Setup....611 Associating your APs....614 Setting up a legacy Cisco Wireless LAN Controller....616 Mucking about with the Startup Wizard....616 Verifying connectivity to the wired LAN....617 Enabling the 802.11 bands....617 Configuring the SSID....618 Configuring WLAN security....618 Configuring WPA keys....619 Setting up Legacy Cisco access points....620 Web authentication process (Guest Captive Portal)....621 Using the Cisco graphical user interface (GUI)....623 Book 6 Security and Management....627 Chapter 1 Defending against Common Attacks with Basic Security Tools....629 Knowing Your Enemy....630 Handling attacks from within....630 Packet sniffing....630 Man in the middle....632 VLAN hopping....632 DHCP attack....633 Cracking cached credentials....633 Masquerade....633 Network scanning....634 Dealing with external attacks....637 SYN flooding....638 Smurf attacks....639 Distributed denial of service (DDoS)....639 Password attacks....640 Implementing Firewalls....641 Types of firewalls....641 Ingress and egress filtering....642 Defending data with the DMZ....642 Defending Your Network against Attacks....644 Perimeter defense....645 Active tools....645 Defense in depth....646 Security Tools....647 Personal firewalls....647 Antivirus software....647 Anti-malware....648 Spam filters....650 Intrusion detection....651 Vulnerability scanners....651 User common sense....651 Chapter 2 Securing Networks with Ciscos Adaptive Security Appliance....653 Getting to Know the Internetwork Operating System....654 Making Connections....655 Running the ASA Setup Wizard....656 Performing a Basic Configuration....667 Device name....667 Standard firewall ports....668 Interfaces....668 IP addresses....671 Security zones....671 Passwords....672 Setting the enable password....673 Setting the SSH password....673 Creating users in the ASDM....675 Banners....677 Setting Up User Accounts....678 Configuring Dynamic Host Configuration Protocol....679 Examining Your License....681 Chapter 3 Securing Networks with ACLs and NAT....685 Securing Networks with ACLs....685 ACL Processing....686 Creating ACLs....687 Standard ACLs....687 Wildcard masks....688 Access Control Entries....689 Modifying ACLs....691 Adding remarks....694 Extended ACLs....695 Applying an ACL....698 Using ACLs as a Virus Detection Tool....701 Where You Can Use ACLs....703 Setting Up Network Address Translation....703 Requirements for NAT....704 Types of NAT....705 Setting up NAT....707 Policy NAT....710 Viewing translations....711 Chapter 4 Cisco Security Best Practices....713 Management Areas....714 Finding Out About Known Issues with Cisco Devices....715 Leveraging Authentication, Authorization, and Accounting....715 Authentication fallback....716 Avoiding Type 7 passwords....716 Centralizing Log Collection and Monitoring....719 Collecting logs in one location....720 Choosing a logging level....721 Dealing with logging in the console, monitor, and buffer....722 Implementing Secure Protocols....723 Managing Configurations....724 Password management....725 Password Retry Lockout....725 Service Password Recovery....726 Managing services....727 Setting up timeouts....728 Keeping alive TCP....729 Leaving room for management....730 Securing SNMP....730 Replacing and rolling back....731 Taking the talking stick with terminal lock....733 Using logs to tell you what is going on....734 Managing network features....735 Port security....736 Anti-spoofing ACLs....737 Getting Physical with Security....737 Chapter 5 AI, Management Tools, and Automation....741 Cisco Automation Tools....742 Cisco Workflows....742 Cisco DNA Center....742 Programmable Infrastructure....743 YANG Models....743 Application Programming Interface (API)....744 NETCONF versus RESTCONF....745 Terraform and Ansible....745 AI in Cisco Products....746 Index....747 EULA....787