Computer Network Security

Description

Developed in collaboration with a training and certification team from Cisco, Computer Network Security is an exploration of the state-of-the-art and good practices in setting up a secure computer system. Concrete examples are offered in each chapter, to help the reader to master the concept and apply the security configuration.

This book is intended for students preparing for the CCNA Security Exam (210-260 IINS) ? whether at professional training centers, technical faculties, or training centers associated with the “Cisco Academy” program. It is also relevant to anyone interested in computer security, be they professionals in this field or users who want to identify the threats and vulnerabilities of a network to ensure better security.

Table of Contents

1. Preface xi
2. Introduction xiii
3. Chapter 1. Fundamentals of Network Security 1
   1. Introduction 1
   2. The main objectives of securing a network 2
   3. Information security terminology 2
   4. Types of network security 4
   5. Physical security 4
   6. Logical security 4
   7. Administrative security 5
   8. The main risks related to the logical security of the network 5
   9. Different kinds of network attacks 5
   10. Network security measures 7
   11. Vulnerability audit measures 8
   12. Exercises to test learning 8
4. Chapter 2. Securing Network Devices 15
   1. Types of network traffic 15
   2. Securing the management plan 16
   3. Securing passwords 16
   4. Implementing connection restrictions 17
   5. Configuring a login banner 17
   6. Configuring connection parameters 17
   7. Securing access through console lines, VTY and auxiliaries 18
   8. Securing access through the console line and deactivating the auxiliary line 18
   9. Securing VTY access with ssh 18
   10. Allocation of administrative roles 19
   11. Privilege levels of the IOS system 19
   12. Configuring a privilege level 19
   13. Setting a privilege level per user 20
   14. Setting a privilege level for console, VTY, and auxiliary line access 20
   15. Securing access with the management of “views” and “super-views” 21
   16. Securing configuration files and the IOS system 22
   17. Using automated security features 23
   18. Securing the control plane 24
   19. Introduction 24
   20. MD5 authentication 24
   21. Configuring OSPF protocol authentication 24
   22. Configuring EIGRP protocol authentication 25
   23. Configuring RIP authentication 26
   24. Exercises for application 26
5. Chapter 3. Supervising a Computer Network 41
   1. Introduction 41
   2. Implementing an NTP server 42
   3. Introduction to the NTP 42
   4. How the NTP works 42
   5. NTP configuration 43
   6. Implementing a Syslog server 44
   7. Introduction to the Syslog 44
   8. How Syslog works 45
   9. Configuring a Syslog client 46
   10. Implementing the Simple Network Management Protocol (SNMP) 46
   11. Introducing the SNMP 46
   12. How SNMP works 47
   13. SNMP configuration 49
   14. Exercises for application 50
6. Chapter 4. Securing Access Using AAA 67
   1. Introduction 67
   2. AAA authentication 68
   3. Local AAA authentication 68
   4. AAA authentication based on a server 69
   5. AAA authorizations 71
   6. AAA traceability 71
   7. Exercises for application 72
7. Chapter 5. Using Firewalls 79
   1. Introducing firewalls 80
   2. Types of firewalls 80
   3. Setting up a firewall 80
   4. Different firewall strategies 81
   5. ACL-based firewalls 81
   6. Introduction 81
   7. The location of ACLs 81
   8. IPv4 ACLs 81
   9. IPv6 ACLs 82
   10. ACL recommendation 83
   11. Zone-based firewalls 84
   12. Introduction 84
   13. Types of security zones in a network 84
   14. Rules applied to interzone traffic 85
   15. Terminology 86
   16. Configuring a ZFW 86
   17. Creating zones 86
   18. Creating Class-Maps 86
   19. Creating the Policy-Map to apply the Class-Maps 87
   20. Defining the zone pairs 87
   21. Applying the policy maps to the zone pairs 87
   22. Assigning interfaces to zones 87
   23. Exercises for application 88
8. Chapter 6. Putting in Place an Intrusion Prevention System (IPS) 101
   1. Introduction to a detector 102
   2. The differences between an IDS and an IPS 102
   3. Types of IPS 103
   4. Cisco IP solutions 103
   5. Modes of deploying IPS 103
   6. Types of alarms 104
   7. Detecting malicious traffic 104
   8. Modes of detection 104
   9. Signature-based detection 104
   10. Other modes of detecting malicious traffic 105
   11. Signature micro-engines 106
   12. Severity levels of the signatures 107
   13. Monitoring and managing alarms and alerts 108
   14. List of actions to be taken during an attack 108
   15. Configuration of an IOS IPS 109
   16. Recommended practices 111
   17. Exercises for application 112
9. Chapter 7. Securing a Local Network 125
   1. Introduction 125
   2. Types of attacks on Layer 2 126
   3. MAC address flooding attacks 126
   4. MAC spoofing attack 127
   5. The DHCP starvation attack 127
   6. VLAN hopping attacks 128
   7. STP-based attacks 130
   8. The best security practices for protecting Layer 2 131
   9. Exercises for application 132
10. Chapter 8. Cryptography 143
    1. Basic concepts in cryptography 143
    2. Definition 143
    3. Terminology 144
    4. The different classifications of cryptology 144
    5. Traditional cryptography 145
    6. Modern cryptography 146
    7. Symmetric and asymmetric encryption 147
    8. Key management 149
    9. Introduction 149
    10. Diffie-Hellman key exchange 149
    11. Hash functions 151
    12. HMAC codes 151
    13. Asymmetric cryptography 151
    14. Introduction 151
    15. How it works 152
    16. Digital signatures 153
    17. Public key infrastructure 155
    18. Exercises for application 159
    19. Chapter 9. IPsec VPNs 173
    20. The IPsec protocol 173
    21. Objectives of IPsec 173
    22. Basic IPsec protocols 174
    23. The IPsec framework 174
    24. The IPsec security association 175
    25. IPsec modes 175
    26. IKE protocol 176
    27. Introduction 176
    28. Components of IKE 176
    29. IKE phases 176
    30. The site-to-site VPN configuration 178
    31. Introduction 178
    32. Configuration of IPsec VPN 179
    33. Exercises for application 181
11. Chapter 10. Studying Advanced Firewalls 189
    1. Cisco ASA firewalls 189
    2. Introduction 189
    3. ASA models 190
    4. Modes for using ASA devices 190
    5. An overview of ASA 5505 191
    6. ASA levels of security 192
    7. Configuring an ASA with CLI 193
    8. Exercises for application 198
    9. Configuring Cisco elements with graphical tools 210
    10. An overview of the CCP 210
    11. An overview of the ASDM 210
    12. Using CCP and ASDM 210
    13. The TMG 2010 firewall 211
    14. Introduction 211
    15. Installation and configuration 211
    16. References 243
    17. Index 245

Author Biography

Ali Sadiqui is a trainer-researcher at the Office de la Formation Professionnelle et de la Promotion du Travail (OFPPT), Morocco. He is a member of several research laboratories and obtained his doctorate from the Sidi Mohamed Ben Abdellah University, Morocco.