NetworkingLesson 8Free preview
CS Firewalls
This lesson is part of Cyber Security · All levels
Summary
A firewall is a device or software that filters network traffic in and out according to security rules set by an administrator. Firewalls can be host-based on one device or network-based on an intermediate device like a router. Modern firewalls are also stateful in nature so they understand the status of active connections.
Key points
- The firewall works based on a set of rules: IP addresses, ports, and protocols.
- Host-based firewalls protect one device; network-based protects multiple devices.
- Stateful firewalls track the status of active connections and assess the context of the package.
- Firewalls are not an antivirus replacement; they protect the path, not the file content.
- Apply the least privilege: only open the ports you really need.
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