Cisco Certified Network Associate (CCNA) - Security
1 Network Security and Secure Connectivity
1-1 Introduction to Network Security
1-1 1 Definition and Importance of Network Security
1-1 2 Threats and Vulnerabilities in Networks
1-1 3 Security Policies and Compliance
1-2 Secure Network Design
1-2 1 Network Segmentation and Zoning
1-2 2 Secure Network Topologies
1-2 3 Designing Secure Network Architectures
1-3 Secure Connectivity
1-3 1 VPN Technologies (IPsec, SSLTLS, GRE)
1-3 2 Remote Access Security
1-3 3 Site-to-Site and Remote Access VPNs
2 Secure Access
2-1 AAA (Authentication, Authorization, and Accounting)
2-1 1 AAA Protocols (RADIUS, TACACS+)
2-1 2 Implementing AAA in Network Devices
2-1 3 Role-Based Access Control (RBAC)
2-2 Identity Management
2-2 1 User Authentication Methods (Passwords, Tokens, Biometrics)
2-2 2 Single Sign-On (SSO) and Federated Identity
2-2 3 Identity Federation and Directory Services
2-3 Access Control Lists (ACLs)
2-3 1 Standard and Extended ACLs
2-3 2 Applying ACLs to Network Devices
2-3 3 ACL Best Practices and Troubleshooting
3 Secure Routing and Switching
3-1 Secure Routing Protocols
3-1 1 OSPF and EIGRP Security
3-1 2 BGP Security (MD5, TCP MD5 Signature Option)
3-1 3 Secure Routing Protocol Configuration
3-2 Secure Switching
3-2 1 Switch Security Features (Port Security, DHCP Snooping)
3-2 2 Implementing Secure VLANs
3-2 3 Switch Security Best Practices
3-3 Network Address Translation (NAT) Security
3-3 1 NAT Types and Security Considerations
3-3 2 Configuring Secure NAT on Routers
3-3 3 NAT and Firewall Integration
4 Secure Wireless Networks
4-1 Wireless Security Protocols
4-1 1 WPA2 and WPA3 Security
4-1 2 RADIUS Integration with Wireless Networks
4-1 3 Wireless Encryption (TKIP, CCMP)
4-2 Secure Wireless Deployment
4-2 1 Wireless Network Design Considerations
4-2 2 Implementing Secure Wireless Access Points
4-2 3 Wireless Intrusion Detection and Prevention Systems (WIDSWIPS)
4-3 Wireless Threats and Mitigation
4-3 1 Common Wireless Attacks (Rogue AP, Evil Twin)
4-3 2 Mitigating Wireless Threats
4-3 3 Wireless Security Best Practices
5 Network Threat Defense
5-1 Intrusion Detection and Prevention Systems (IDSIPS)
5-1 1 IDSIPS Technologies and Architectures
5-1 2 Signature-Based and Anomaly-Based Detection
5-1 3 Implementing and Managing IDSIPS
5-2 Firewalls and Network Security
5-2 1 Firewall Types (Stateful, Stateless, Next-Generation)
5-2 2 Firewall Policies and Rules
5-2 3 Configuring and Managing Firewalls
5-3 Network Access Control (NAC)
5-3 1 NAC Architectures and Protocols
5-3 2 Implementing NAC Solutions
5-3 3 NAC Best Practices and Troubleshooting
6 Secure Network Management and Monitoring
6-1 Network Management Protocols
6-1 1 SNMP Security (v1, v2c, v3)
6-1 2 Secure Network Management Practices
6-1 3 Implementing Secure SNMP
6-2 Network Monitoring and Logging
6-2 1 Network Monitoring Tools and Techniques
6-2 2 Log Management and Analysis
6-2 3 Monitoring and Logging Best Practices
6-3 Network Device Hardening
6-3 1 Device Hardening Techniques
6-3 2 Secure Device Configuration
6-3 3 Device Hardening Best Practices
7 Cryptography and VPNs
7-1 Cryptographic Concepts
7-1 1 Symmetric and Asymmetric Encryption
7-1 2 Hashing and Digital Signatures
7-1 3 Public Key Infrastructure (PKI)
7-2 VPN Technologies
7-2 1 IPsec VPN Architecture
7-2 2 SSLTLS VPNs
7-2 3 VPN Deployment and Management
7-3 Secure Communication Protocols
7-3 1 Secure Email (SMIME, PGP)
7-3 2 Secure Web Protocols (HTTPS, SSLTLS)
7-3 3 Secure Communication Best Practices
8 Security Incident Response and Management
8-1 Incident Response Planning
8-1 1 Incident Response Process (IRP)
8-1 2 Incident Handling and Containment
8-1 3 Incident Response Best Practices
8-2 Forensics and Evidence Collection
8-2 1 Network Forensics Techniques
8-2 2 Evidence Collection and Preservation
8-2 3 Forensics Best Practices
8-3 Disaster Recovery and Business Continuity
8-3 1 Disaster Recovery Planning (DRP)
8-3 2 Business Continuity Planning (BCP)
8-3 3 Disaster Recovery and BCP Best Practices
5.1.2 Signature-Based and Anomaly-Based Detection

5.1.2 Signature-Based and Anomaly-Based Detection

Key Concepts

Signature-Based Detection

Signature-Based Detection is a method used by Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS) to identify malicious activities by comparing network traffic against a database of known attack patterns, or signatures. These signatures are specific patterns, such as specific byte sequences or command sequences, that are characteristic of known cyber threats.

Example: A signature-based IDS detects a network packet containing a specific sequence of bytes that matches the signature of a known malware variant. The IDS flags this packet as malicious and takes appropriate action, such as blocking the packet or alerting the administrator.

Analogies: Think of signature-based detection as a fingerprint identification system. Just as a fingerprint is unique to an individual, a signature is unique to a specific cyber threat.

Anomaly-Based Detection

Anomaly-Based Detection is a method used by IDS and IPS to identify potential security threats by monitoring network traffic for deviations from established normal behavior patterns. This method involves creating a baseline of normal network activity and then flagging any activity that significantly deviates from this baseline as suspicious.

Example: An anomaly-based IDS monitors the network for unusual spikes in traffic volume or unexpected changes in user behavior. If the IDS detects a sudden increase in outbound traffic from a user's workstation, it may flag this activity as suspicious and investigate further.

Analogies: Consider anomaly-based detection as a thermostat that monitors room temperature. Just as a thermostat detects deviations from the set temperature and takes action, an anomaly-based IDS detects deviations from normal network behavior and responds accordingly.

Conclusion

Understanding Signature-Based and Anomaly-Based Detection is crucial for implementing effective Intrusion Detection and Prevention Systems. Signature-Based Detection relies on known attack patterns to identify threats, while Anomaly-Based Detection identifies threats by detecting deviations from normal network behavior. By combining these methods, organizations can create a robust security framework that protects against both known and emerging cyber threats.