Firewall

A firewall is used to filter incoming and outgoing traffic over a network, providing security by controlling the flow of data.

TryHackMe

Types of Firewalls

Firewall Type	Characteristics
Stateless Firewalls	- Basic filtering - No tracking of previous connections - Efficient for high-speed networks
Stateful Firewalls	- Recognizes traffic patterns - Supports complex rules - Monitors network connections
Proxy Firewalls	- Inspects packet content - Provides content filtering and application control - Can decrypt and inspect SSL/TLS traffic
Next-Generation Firewalls	- Advanced threat protection - Includes Intrusion Prevention System (IPS) - Uses heuristic analysis to identify anomalies - Decrypts SSL/TLS traffic

Firewall Solutions

Pfsense

Firewall oriented OS for devices.

Windows

Windows Defender Firewall: Built-in firewall that offers protection against both inbound and outbound threats.

Linux

• iptables: Commonly used in many Linux distributions, it uses the Netfilter framework to control network traffic.

• nftables: Successor to iptables, offering enhanced packet filtering and NAT (Network Address Translation) capabilities, also based on the Netfilter framework.

• firewalld: Uses predefined rule sets and zone configurations for easier management and better performance. It’s different from iptables and nftables.

• ufw (Uncomplicated Firewall): A user-friendly firewall that simplifies the process of configuring firewall rules by providing an easier interface to iptables or nftables.