This guide walks Linux operators through the fundamentals of Netfilter, explains iptables tables, chains and rule‑matching order, and provides step‑by‑step commands for configuring, saving, and troubleshooting iptables, firewalld and ufw in production environments.
This comprehensive guide explains how to harden an Ubuntu‑based Kubernetes cluster with external IPs by applying system hardening, firewall rules, TLS encryption, Calico network policies, RBAC permissions, audit logging, and verification steps to achieve a multi‑layered security posture.
This article introduces Ubuntu’s Uncomplicated Firewall (UFW), explaining how to enable, disable, reset, set default policies, and create, modify, or delete specific IP, port, and protocol rules using concise command-line examples, helping users quickly secure client machines with practical firewall configurations.
This guide walks you through securing an Ubuntu‑hosted Kubernetes cluster by configuring system settings, firewall rules, TLS encryption, network policies, RBAC permissions, audit logging, and verification steps, providing a layered defense strategy for production environments.
Learn how to quickly set up and manage Ubuntu’s Uncomplicated Firewall (UFW) with step‑by‑step commands for enabling, disabling, resetting, configuring default policies, adding protocol, IP, and port rules, and deleting rules, empowering you to secure client machines efficiently.
This guide walks through securing an Ubuntu 20.04 server by updating packages, changing the default SSH port, enforcing strong passwords, creating a non‑root user with sudo, disabling root login, enabling RSA key authentication, configuring the UFW firewall, and blocking ping requests.
An overview of essential Linux firewall solutions—including iptables, IPCop, Shorewall, UFW, Vuurmuur, pfSense, IPFire, Smoothwall, Endian, and ConfigServer—covers their core functions, key features, and typical use cases, helping administrators choose the right tool for network protection.
After a Raspberry Pi’s SSH service was overwhelmed by brute‑force login attempts, the author explains how to examine auth.log, identify malicious IPs, and protect the device by configuring /etc/hosts.allow / hosts.deny and setting up UFW whitelist rules to allow only trusted addresses.
This article explains how a Raspberry Pi exposed to the Internet was repeatedly attacked via SSH, how the author identified the brute‑force attempts in /var/log/auth.log, and step‑by‑step methods using hosts.allow/deny and ufw to whitelist trusted IPs and block malicious traffic.
