Understanding Firewalls (UFW/firewalld)
Learn the concepts of firewalls and how to use common tools like UFW (Ubuntu) or firewalld (CentOS) to control network traffic.
Your Server's Digital Guard
Imagine your server as a house. A firewall acts like a security guard at the door, deciding who gets in and out. It's a critical part of server security.
Firewalls prevent unauthorized access and protect your server from malicious attacks by controlling network traffic.
How Firewalls Filter Traffic
Firewalls work by using a set of rules to inspect incoming and outgoing network traffic. These rules are based on:
- Source/Destination IP Address: Where traffic comes from or goes.
- Port Numbers: Specific 'doors' for services (e.g., port 22 for SSH, 80 for HTTP).
- Protocols: Like TCP or UDP.
They either allow or deny traffic that matches these rules.
All lessons in this course
- Basic Network Configuration
- Understanding Firewalls (UFW/firewalld)
- Port Management & Security
- DNS Configuration and Troubleshooting