Safer Internet: Connection: Use a Firewall

Summary | Built-in Software | Block Ports | Other Software |
References: General | macOS | Windows

Summary

• Routers typically provide some hardware firewall protection, plus a layer of anonymity.
• [1] Enable your device's built-in software firewall; default (mostly inbound) settings are usually adequate
• [2] Block/unblock specific ports/services via router or OS, e.g., if you're a gamer or server admin
• [3] Install 3rd party software for more advanced inbound and/or outbound firewall
• References

[1] Enable your device's built-in software firewall

• iOS: not necessary
• macOS: System Preferences > Security & Privacy > Firewall > Turn On
  [screenshot] you'll need to click the lock and provide your admin password
• macOS: {Figure 9. TCYOP-4: 76; TCYOP-3: 62}; Win: {Figure 8. TCYOP-4: 75; TCYOP-3: 61}

[2] Block/unblock specific ports/services

• macOS: System Preferences > Security & Privacy > Firewall > Firewall Options [screenshot]

[3] Install 3rd party software

• Install 3rd party software for more advanced inbound and/or outbound firewall {TCYOP-4: 66}
• macOS: Little Snitch; Lulu; others: Intego NetBarrier; Murus; Norton Security; Radio Silence
• macOS: access secondary built-in firewall pf via Terminal, or GUI: Murus
• Windows: ZoneAlarm; Windows 8 Firewall Control

References

• {TCYOP-4: 74-77; TCYOP-3: 61-63; Use an Outbound Firewall; Beware Analog Snooping, Too}
• sections: Refs: macOS, Windows
• Wikipedia: Firewall controls incoming and outgoing network traffic; router
• Wikipedia: Firewalls and Internet security; Personal firewall
• HowStuffWorks: How Firewalls Work

macOS

• Apple: firewall
• Little Snitch 6.0.4 TB; 8/5/2024
• How to Enable or Disable Firewall on MacOS Ventura OSXD; 5/17/2023
• Apple has removed a controversial feature in macOS 11.2 beta 2 that allowed its own apps to bypass third-party firewalls, security tools, and VPNs ZD; 1/14/2021

Win

• Wikipedia: Windows firewall