Firewall

For linux, iptables is a tried-and-true solution for a system firewall.

https://www.digitalocean.com/community/tutorials/iptables-essentials-common-firewall-rules-and-commands

See currently configured rules

iptables -nvL | less

http://firehol.org/guides/firehol-welcome/
FireHOL - FireHOL Welcome Guide
http://firehol.org/documentation/#firehol
FireHOL - Documentation
http://firehol.org/
FireHOL - Linux firewalling and traffic shaping for humans
https://github.com/firehol/firehol
firehol/firehol: A firewall for humans...
https://github.com/trimstray/iptables-essentials
trimstray/iptables-essentials: Iptables Essentials: Common Firewall Rules and Commands.
https://major.io/2010/04/12/best-practices-iptables/
Best practices: iptables | Major Hayden
https://duckduckgo.com/?t=ffab&q=iptables+init+&ia=web
iptables init at DuckDuckGo
https://github.com/BorX/iptables-init
BorX/iptables-init: Easy initialization iptables rules
https://github.com/topics/iptables
iptables · GitHub Topics
https://github.com/cloudnativelabs/kube-router
cloudnativelabs/kube-router: Kube-router, a turnkey solution for Kubernetes networking.
https://github.com/topics/firewall
firewall · GitHub Topics
https://github.com/fatedier/frp
fatedier/frp: A fast reverse proxy to help you expose a local server behind a NAT or firewall to the internet.
https://github.com/topics/bastion
bastion · GitHub Topics
https://duckduckgo.com/?q=firehol+router+hardware&t=ffab&ia=web
firehol router hardware at DuckDuckGo
https://avine.sh/b/robust-raspberry-pi-wifi-router-firewall-qos/
Building robust Raspberry Pi wireless router with firewall and QoS inbuilt - Avinesh Singh
https://wiki.archlinux.org/title/Router
Router - ArchWiki
https://www.raspberrypi.com/documentation/computers/configuration.html
Raspberry Pi Documentation - Configuration
https://github.com/RaspAP/raspap-webgui/wiki/FAQs#can-i-integrate-raspap-with-adguard-home
FAQs · RaspAP/raspap-webgui Wiki
https://github.com/RaspAP/raspap-webgui
RaspAP/raspap-webgui: Simple wireless AP setup & management for Debian-based devices

https://docs.opnsense.org/development/architecture.html Architecture — OPNsense documentation https://github.com/opnsense/core GitHub - opnsense/core: OPNsense GUI, API and systems backend https://github.com/topics/firewall firewall · GitHub Topics · GitHub https://duckduckgo.com/?q=UFW+Tutoria&t=fpas&ia=web UFW Tutoria at DuckDuckGo https://askubuntu.com/questions/1263586/whats-the-best-firewall-for-ubuntu security - Whats the best firewall for ubuntu? - Ask Ubuntu https://duckduckgo.com/?q=ubuntu+desktop+firewall&t=fpas&ia=web ubuntu desktop firewall at DuckDuckGo https://www.reddit.com/r/linuxquestions/comments/b4aowu/gui_firewall_to_allowblock_specific_applications/ GUI Firewall To Allow/Block Specific Applications? : linuxquestions https://duckduckgo.com/?q=opensnitch+vs+ufw&t=fpas&ia=web opensnitch vs ufw at DuckDuckGo https://github.com/gravitational/teleport GitHub - gravitational/teleport: Certificate authority and access plane for SSH, Kubernetes, web apps, databases and desktops https://github.com/evilsocket/opensnitch/wiki/Configurations Configurations · evilsocket/opensnitch Wiki · GitHub https://github.com/evilsocket/opensnitch/wiki Home · evilsocket/opensnitch Wiki · GitHub https://github.com/evilsocket/opensnitch GitHub - evilsocket/opensnitch: OpenSnitch is a GNU/Linux port of the Little Snitch application firewall https://ubuntu.com/server/docs/security-firewall Security - Firewall | Ubuntu