Introduction xxxi Chapter 1 Single-Area OSPFv2 Concepts 1 Objectives 1 Key Terms 1 Introduction (1.0) 3 OSPF Features and Characteristics (1.1) 3 Introduction to OSPF (1.1.1) 3 Components of OSPF (1.1.2) 4 Routing Protocol Messages 4 Data Structures 4 Algorithm 5 Link-State Operation (1.1.

3) 6 1. Establish Neighbor Adjacencies 6 2. Exchange Link-State Advertisements 6 3. Build the Link-State Database 7 4. Execute the SPF Algorithm 8 5. Choose the Best Route 8 Single-Area and Multiarea OSPF (1.1.4) 9 Multiarea OSPF (1.

1.5) 10 OSPFv3 (1.1.6) 12 OSPF Packets (1.2) 13 Types of OSPF Packets (1.2.2) 13 Link-State Updates (1.2.

3) 14 Hello Packet (1.2.4) 15 OSPF Operation (1.3) 17 OSPF Operational States (1.3.2) 17 Establish Neighbor Adjacencies (1.3.3) 18 1.

Down State to Init State 18 2. The Init State 19 3. Two-Way State 19 4. Elect the DR and BDR 20 Synchronizing OSPF Databases (1.3.4) 20 1. Decide First Router 21 2. Exchange DBDs 21 3.

Send an LSR 22 The Need for a DR (1.3.5) 23 LSA Flooding with a DR (1.3.6) 24 Flooding LSAs 24 LSAs and DR 25 Summary (1.4) 27 OSPF Features and Characteristics 27 OSPF Packets 28 OSPF Operation 28 Practice 29 Check Your Understanding 29 Chapter 2 Single-Area OSPFv2 Configuration 33 Objectives 33 Key Terms 33 Introduction (2.0) 34 OSPF Router ID (2.1) 34 OSPF Reference Topology (2.

1.1) 34 Router Configuration Mode for OSPF (2.1.2) 35 Router IDs (2.1.3) 36 Router ID Order of Precedence (2.1.4) 36 Configure a Loopback Interface as the Router ID (2.

1.5) 37 Explicitly Configure a Router ID (2.1.6) 38 Modify a Router ID (2.1.7) 39 Point-to-Point OSPF Networks (2.2) 40 The network Command Syntax (2.2.

1) 40 The Wildcard Mask (2.2.2) 41 Configure OSPF Using the network Command (2.2.4) 41 Configure OSPF Using the ip ospf Command (2.2.6) 43 Passive Interface (2.2.

8) 44 Configure Passive Interfaces (2.2.9) 45 OSPF Point-to-Point Networks (2.2.11) 46 Loopbacks and Point-to-Point Networks (2.2.12) 48 Multiaccess OSPF Networks (2.3) 49 OSPF Network Types (2.

3.1) 49 OSPF Designated Router (2.3.2) 49 OSPF Multiaccess Reference Topology (2.3.3) 51 Verify OSPF Router Roles (2.3.4) 52 R1 DROTHER 52 R2 BDR 53 R3 DR 53 Verify DR/BDR Adjacencies (2.

3.5) 54 R1 Adjacencies 55 R2 Adjacencies 55 R3 Adjacencies 56 Default DR/BDR Election Process (2.3.6) 56 DR Failure and Recovery (2.3.7) 58 R3 Fails 58 R3 Rejoins Network 59 R4 Joins Network 59 R2 Fails 59 The ip ospf priority Command (2.3.8) 61 Configure OSPF Priority (2.

3.9) 61 Modify Single-Area OSPFv2 (2.4) 63 Cisco OSPF Cost Metric (2.4.1) 63 Adjust the Reference Bandwidth (2.4.2) 64 OSPF Accumulates Costs (2.4.

3) 66 Manually Set OSPF Cost Value (2.4.4) 67 Test Failover to Backup Route (2.4.5) 69 Hello Packet Intervals (2.4.7) 69 Verify Hello and Dead Intervals (2.4.

8) 70 Modify OSPFv2 Intervals (2.4.9) 71 Default Route Propagation (2.5) 73 Propagate a Default Static Route in OSPFv2 (2.5.1) 74 Verify the Propagated Default Route (2.5.2) 75 Verify Single-Area OSPFv2 (2.

6) 77 Verify OSPF Neighbors (2.6.1) 77 Verify OSPF Protocol Settings (2.6.2) 79 Verify OSPF Process Information (2.6.3) 80 Verify OSPF Interface Settings (2.6.

4) 81 Summary (2.7) 83 OSPF Router ID 83 Point-to-Point OSPF Networks 83 OSPF Network Types 84 Modify Single-Area OSPFv2 85 Default Route Propagation 86 Verify Single-Area OSPFv2 86 Practice 87 Check Your Understanding 88 Chapter 3 Network Security Concepts 93 Objectives 93 Key Terms 93 Introduction 95 Ethical Hacking Statement (3.0.3) 95 Current State of Cybersecurity (3.1) 95 Current State of Affairs (3.1.1) 95 Vectors of Network Attacks (3.1.

2) 96 Data Loss (3.1.3) 97 Threat Actors (3.2) 98 The Hacker (3.2.1) 98 Evolution of Hackers (3.2.2) 99 Cyber Criminals (3.

2.3) 100 Hacktivists (3.2.4) 100 State-Sponsored Hackers (3.2.5) 100 Threat Actor Tools (3.3) 101 Introduction to Attack Tools (3.3.

2) 101 Evolution of Security Tools (3.3.3) 102 Attack Types (3.3.4) 104 Malware (3.4) 106 Overview of Malware (3.4.1) 106 Viruses and Trojan Horses (3.

4.2) 106 Other Types of Malware (3.4.3) 108 Common Network Attacks (3.5) 109 Overview of Network Attacks (3.5.1) 109 Reconnaissance Attacks (3.5.

3) 109 Access Attacks (3.5.5) 110 Trust Exploitation Example 111 Port Redirection Example 112 Man-in-the-Middle Attack Example 112 Buffer Overflow Attack 112 Social Engineering Attacks (3.5.6) 114 DoS and DDoS Attacks (3.5.9) 115 DoS Attack 116 DDoS Attack 116 IP Vulnerabilities and Threats (3.6) 117 IPv4 and IPv6 (3.

6.2) 118 ICMP Attacks (3.6.3) 118 Amplification and Reflection Attacks (3.6.5) 119 Address Spoofing Attacks (3.6.6) 120 TCP and UDP Vulnerabilities (3.

7) 122 TCP Segment Header (3.7.1) 122 TCP Services (3.7.2) 123 TCP Attacks (3.7.3) 124 TCP SYN Flood Attack 124 TCP Reset Attack 125 TCP Session Hijacking 126 UDP Segment Header and Operation (3.7.

4) 126 UDP Attacks (3.7.5) 127 UDP Flood Attacks 127 IP Services 127 ARP Vulnerabilities (3.8.1) 127 ARP Cache Poisoning (3.8.2) 128 ARP Request 128 ARP Reply 129 Spoofed Gratuitous ARP Replies 130 DNS Attacks (3.8.

4) 131 DNS Open Resolver Attacks 131 DNS Stealth Attacks 132 DNS Domain Shadowing Attacks 132 DNS Tunneling (3.8.5) 132 DHCP (3.8.6) 133 DHCP Attacks (3.8.7) 134 1. Client Broadcasts DHCP Discovery Messages 134 2.

DHCP Servers Respond with Offers 134 3. Client Accepts Rogue DHCP Request 136 4. Rogue DHCP Acknowledges the Request 136 Network Security Best Practices (3.9) 137 Confidentiality, Integrity, and Availability (3.9.1) 137 The Defense-in-Depth Approach (3.9.2) 138 Firewalls (3.

9.3) 139 IPS (3.9.4) 140 Content Security Appliances (3.9.5) 141 Cisco Email Security Appliance (ESA) 142 Cisco Web Security Appliance (WSA) 142 Cryptography (3.10) 143 Securing Communications (3.10.

2) 143 Data Integrity (3.10.3) 144 Hash Functions (3.10.4) 145 MD5 with 128-Bit Digest 145 SHA Hashing Algorithm 146 SHA-2 146 SHA-3 146 Origin Authentication (3.10.5) 147 HMAC Hashing Algorithm 147 Creating the HMAC Value 148 Verifying the HMAC Value 149 Cisco Router HMAC Example 149 Data Confidentiality (3.10.

6) 150 Symmetric Encryption (3.10.7) 151 Asymmetric Encryption (3.10.8) 152 Diffie-Hellman (3.10.9) 155 Summary (3.11) 157 Current State of Cybersecurity 157 Threat Actors 157 Threat Actor Tools 157 Malware 157 Common Network Attacks 158 IP Vulnerabilities and Threats 158 TCP and UDP Vulnerabilities 158 IP Services 158 Network Security Best Practices 159 Cryptography 159 Practice 159 Check Your Understanding 160 Chapter 4 ACL Concepts 163 Objectives 163 Key Terms 163 Introduction (4.

0) 164 Purpose of ACLs (4.1) 164 What Is an ACL? (4.1.1) 164 Packet Filtering (4.1.2) 165 ACL Operation (4.1.3) 166 Wildcard Masks in ACLs (4.

2) 168 Wildcard Mask Overview (4.2.1) 168 Wildcard Mask Types (4.2.2) 169 Wildcard to Match a Host 169 Wildcard Mask to Match an IPv4 Subnet 169 Wildcard Mask to Match an IPv4 Address Range 170 Wildcard Mask Calculation (4.2.3) 170 Example 1 171 Example 2 171 Example 3 171 Example 4 172 Wildcard Mask Keywords (4.2.

4) 172 Guidelines for ACL Creation (4.3) 173 Limited Number of ACLs per Interface (4.3.1) 173 ACL Best Practices (4.3.2) 174 Types of IPv4 ACLs (4.4) 175 Standard and Extended ACLs (4.4.

1) 175 Numbered and Named ACLs (4.4.2) 176 Numbered ACLs 176 Named ACLs 177 Where to Place ACLs (4.4.3) 177 Standard ACL Placement Example (4.4.4) 179 Extended ACL Placement Example (4.4.

5) 180 Summary (4.5) 182 Purpose of ACLs 182 Wildcard Masks 182 Guidelines for ACL Creation 183 Types of IPv4 ACLs 183 Practice 184 Check Your Understanding Questions 184 Chapter 5 ACLs for IPv4 Configuration 187 Objectives 187 Key Term 187 Introduction (5.0) 188 Configure Standard IPv4 ACLs (5.1) 188 Create an ACL (5.1.1) 188 Numbered Standard IPv4 ACL Syntax (5.1.2) 188 Named Standard IPv4 ACL Syntax (5.

1.3) 189 Apply a Standard IPv4 ACL (5.1.4) 190 Numbered Standard IPv4 ACL Example (5.1.5) 191 Named Standard IPv4 ACL Example (5.1.6) 193 Modify IPv4 ACLs (5.

2) 195 Two Methods to Modify an ACL (5.2.1) 196 Text Editor Method (5.2.2) 196 Sequence Numbers Method (5.2.3) 197 Modify a Named ACL Example (5.2.

4) 198 ACL Statistics (5.2.5) 199 Secure VTY Ports with a Standard IPv4 ACL (5.3) 200 The access-class Command (5.3.1) 200 Secure VTY Access Example (5.3.2) 200 Verify the VTY Port Is Secured (5.

3.3) 202 Configure Extended IPv4 ACLs (5.4) 203 Extended ACLs (5.4.1) 203 Number.