Firewall Types

Firewalls control network traffic by allowing or denying the flow of data between different networks based on a set of security rules.

OSI Layers

  • Layer 4: Traditional firewalls operate at the transport layer, filtering TCP and UDP traffic based on IP addresses and port numbers.
  • Layer 7: Next-Generation Firewalls (NGFW) operate at the application layer, providing more granular control by analyzing application-specific traffic.

UTM - Unified Threat Management

  • An older type of firewall that combines multiple security functions, such as antivirus, intrusion detection, and content filtering, into a single device.
  • Often referred to as an "all-in-one" security appliance.

NGFW - Next-Generation Firewall

  • A more advanced firewall that operates at the application layer (Layer 7 of the OSI model), capable of inspecting and monitoring traffic at a deeper level to provide comprehensive security.

WAF - Web Application Firewall

  • A firewall specifically designed to protect web applications by analyzing and filtering HTTP traffic, blocking malicious inputs such as SQL injection and cross-site scripting (XSS).