Network Security Fundamentals

Unique Characteristics of Networks

• Networks differ based on organizational goals and environment (e.g., manufacturing vs. medical).
• Despite differences, common elements exist across networks, such as firewalls.

Network Security Components

• Firewalls: Segregate network to control traffic, keeping attackers out.
• Other Security Devices:
  • Honeypots
  • Jump servers
  • Network sensors
  • Load balancers

Security Zones

• Definition: Logical separation of devices by use or access type, distinct from IP ranges/subnets.
• Basic Configuration: Trusted vs. Untrusted zones.
  • Trusted Zone: Internal, sensitive data.
  • Untrusted Zone: External, internet-facing.
• Granular Configurations:
  • Specific zones such as inside, internet, servers, databases, screened.
• Benefits:
  • Clear security rule definitions.
  • Easier management of large rule bases.

Security Zone Implementation

• Example setup with distinct zones:
  • Internet Zone
  • Screened Zone
  • Inside Zone (more granularity and precise rules)

Attack Surface

• Definition: Potential vulnerabilities in the network.
• Minimization Strategies:
  • Audit application code.
  • Block unnecessary ports.
  • Real-time traffic monitoring.

Network Connectivity Security

• Physical Security: Protect network cabling from tampering.
• Logical Security: Application-level encryption to protect data integrity.
• Remote Access Security:
  • IPsec tunnels
  • VPN concentrators for secure external connections