Firewall
A firewall is a network security device or software that monitors and controls incoming and outgoing network traffic based on predetermined security rules.
A firewall is a network security device or software that monitors and controls incoming and outgoing network traffic based on predetermined security rules.
Types of Firewalls
Hardware Firewall
A physical device placed between your network and the internet (e.g. in routers or enterprise setups).
Software Firewall
Installed on individual devices (like Windows Defender Firewall).
Network Firewall
Protects an entire network, often in corporate environments.
Host-based Firewall
Protects a single device or host.
How Firewalls Work
They use rules to allow or block traffic. These rules are based on:
IP addresses
Port numbers
Protocols (e.g., TCP, UDP)
Applications
Packet content (in advanced firewalls)
Firewall types
Packet-filtering
Looks at packets’ headers (IP, port, protocol). Fast but basic.
Stateful inspection
Tracks active connections and makes smarter decisions.
Application-layer (Next-Gen)
Understands and filters traffic at the app level (e.g., block Facebook).
Proxy Firewall
Acts as a gateway between you and the internet, hiding your IP.
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