Network Security Fundamentals

Course Overview

• Instructor: Chris, Chief Information Security Officer, Google Fiber
• Focus: Understanding the structure of networks, network operations, protocols, and security hardening practices

Importance of Network Security

• Rising frequency and complexity of network-based attacks
• Essential for security analysts to protect organizational networks

Network Basics

Structure of Networks

• Local Area Network (LAN): Small geographical area (e.g., home, office)
• Wide Area Network (WAN): Large geographical area (e.g., city, country)

Network Devices

• Hub: Broadcasts information to all devices
• Switch: Sends data to specific devices, more secure than hubs
• Router: Connects multiple networks, directs data to its destination network
• Modem: Connects router to the internet
• Virtualization Tools: Software performing network operations, cost-saving and scalable

Cloud Networks

• Use of remote servers instead of local physical devices
• Offers cost savings and efficiency
• Important for organizations moving to cloud services

Network Protocols

TCP/IP Model

• Transmission Control Protocol (TCP): Establishes connections, streams data
• Internet Protocol (IP): Routes and addresses data packets

Common Protocols

• HTTPS: Secure web communication
• DNS: Translates domain names into IP addresses

Firewalls and Security Zones

Firewalls

• Types: Hardware, software, cloud-based
• Functionality: Stateless vs. stateful inspection, Next Generation Firewalls (NGFW)

VPNs and Proxies

• VPN: Changes public IP, encrypts data
• Proxy Servers: Adds security by hiding private network’s IP address

Network Attacks

Common Attacks

• Denial of Service (DoS) / Distributed DoS (DDoS): Overloads network to disrupt operations
• Packet Sniffing: Unauthorized monitoring of network data
• IP Spoofing: Impersonating authorized systems to gain access

Security Hardening

• OS Hardening: Regular updates, strong password policies, multi-factor authentication
• Network Hardening: Port filtering, network segmentation, use of encryption
• Cloud Hardening: Maintaining security in cloud networks, shared responsibility with providers

Conclusion

• Understanding network architecture and security practices is crucial for security analysts
• Next steps: Computing basics for security analysts, focusing on Linux command line and SQL