Network SecurityMedium
Firewall
A network security device that monitors and controls incoming and outgoing network traffic
Skill Paths:
Network SecurityNetwork AdministrationSecurity Fundamentals
Job Paths:
Network Security EngineerNetwork AdministratorSecurity EngineerSecurity Analyst
Relevant Certifications:
CompTIA Security+Cisco CCNA SecurityCISSPSANS GSEC
Content
What is a Firewall?
Firewalls act as a barrier between trusted internal networks and untrusted external networks. They examine network traffic and decide whether to allow or block it based on predefined security rules.
Types of Firewalls
- Packet Filtering Firewalls – Basic traffic filtering
- Stateful Firewalls – Track connection state
- Application Layer Firewalls – Deep packet inspection
- Next-Generation Firewalls – Advanced threat protection
Best Practices
- Use defense in depth with multiple firewall layers
- Regularly update firewall rules
- Monitor and log all traffic
- Test firewall configurations regularly
Quick Facts
Severity Level
7/10
Types
Packet Filtering, Stateful, Application Layer
Placement
Network perimeter, internal segments
Purpose
Control network traffic flow
Example
Blocking unauthorized access to internal servers
Related Terms