Firewall Types - CompTIA Security+ SY0-701 - 3.2
Understanding Firewalls and Their Functionality
Introduction to Firewalls
- Firewalls are essential for controlling traffic flow between two points, commonly used in homes, offices, and operating systems.
- They manage internet communication, especially crucial in large environments with numerous users.
Firewall Applications
- Firewalls can restrict access to specific websites or content, useful in corporate settings for employee monitoring.
- Home firewalls may provide parental controls while also enhancing security through antivirus and anti-malware features.
Types of Firewalls
Network-Based Firewalls
- Traditional network-based firewalls operate at OSI layer 4 (TCP/UDP ports), while next-generation firewalls function at OSI layer 7 (application layer).
Unified Threat Management (UTM)
- Older firewalls often bundle multiple features into a single device known as UTM or Unified Threat Management devices.
- UTMs can perform URL filtering, content inspection, malware identification, spam filtering, and more.
Advanced Firewall Features
Next-Generation Firewalls (NGFW)
- NGFW operates at OSI layer 7 allowing for application-specific traffic management rather than just port number reliance.
- These firewalls conduct full packet inspection to determine the nature of the traffic and make informed forwarding decisions.
Application Layer Control
- NGFW can allow or block applications based on their type regardless of port numbers; e.g., permitting SQL Server traffic but restricting social media posting.
Intrusion Prevention Capabilities
- Many NGFW include vulnerability databases that enable them to act as intrusion prevention systems by blocking known threats.
Web Application Firewall (WAF)
Web Application Firewalls and Their Importance
Overview of Web Application Firewalls (WAF)
- Web application firewalls are often used in conjunction with next-generation firewalls to enhance network security by analyzing different types of traffic and making distinct forwarding decisions.
- The implementation of a web application firewall may be mandated by security directives aimed at protecting the network infrastructure.
Regulatory Standards and WAF
- The Payment Card Industry Data Security Standard (PCI DSS) emphasizes the necessity of web application firewalls to safeguard credit card transactions and related applications.
Log File Analysis from WAF
- A log file example from a web application firewall illustrates various blocked attacks targeting web-based applications, including SQL injections and cross-site scripting.