Firewall

Common Problems 115944

Ubuntu 26.04 LTS – UFW policy change blocks SSH access – Fix & Prevention

🔴 Critical   ⏱ 5–30 min  Last verified: 17 July 2026 Affected versions: Ubuntu 26.04 LTS 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors […]

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How to Configure Nginx Server Blocks (Virtual Hosts) on Ubuntu 26.04 — step-by-step Linux tutorial on Progressive Robot

How to Install Apache on Ubuntu 26.04

Apache HTTP Server is one of the most widely used web servers in the world. Its modular architecture supports a huge range of functionality including URL rewriting, authentication, and SSL. This guide installs Apache on Ubuntu 26.04 LTS and configures the firewall. Tested and valid on: Ubuntu 26.04 LTS Prerequisites Ubuntu 26.04 LTS server A […]

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How to Configure dnsmasq on FreeBSD 15 — step-by-step FreeBSD 15 tutorial on Progressive Robot

How to Configure dnsmasq on FreeBSD 15

Introduction Deploying configure dnsmasq on a FreeBSD 15 machine differs from Linux in several important ways: packages come from the FreeBSD Ports Collection or the binary pkg repository, services are registered in /etc/rc.conf via sysrc(8), and firewall rules are written in pf.conf(5) syntax. This tutorial stays entirely within the standard base + ports approach so […]

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How to Configure Mandatory Access Control (MAC) on FreeBSD 15 — step-by-step FreeBSD 15 tutorial on Progressive Robot

How to Configure Mandatory Access Control (MAC) on FreeBSD 15

Introduction This guide explains how to Configure Mandatory Access Control (MAC) on FreeBSD 15 on FreeBSD 15. FreeBSD uses the pkg(8) binary package manager, rc.conf(5) for service startup configuration, and pf(4) as its primary packet filter. There is no SELinux or AppArmor — instead, FreeBSD provides the MAC (Mandatory Access Control) framework and Capsicum for […]

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How to Install Scala and sbt on RHEL 10 — step-by-step RHEL 10 tutorial on Progressive Robot

How to Install Scala and sbt on RHEL 10

Introduction Setting up install scala and sbt on a RHEL 10 server is a common task for system administrators, DevOps engineers, and site reliability engineers. This guide explains how to Install Scala and sbt on RHEL 10, with all the commands you need, the SELinux and firewalld considerations to keep in mind, and how to […]

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How to Build Multi-Stage Docker Images on Oracle Linux 10 — step-by-step Oracle Linux 10 tutorial on Progressive Robot

How to Build Multi-Stage Docker Images on Oracle Linux 10

Introduction Oracle Linux 10 ships with a stable, security-hardened base that makes deploying build multi-stage docker images on oracle linux 10 both straightforward and auditable. This tutorial covers the complete procedure for how to Build Multi-Stage Docker Images on Oracle Linux 10, including dnf module streams where applicable, systemd unit management, and the firewalld rules […]

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How to Configure GitLab CE on FreeBSD 15 — step-by-step FreeBSD 15 tutorial on Progressive Robot

How to Configure GitLab CE on FreeBSD 15

Introduction Deploying configure gitlab ce on a FreeBSD 15 machine differs from Linux in several important ways: packages come from the FreeBSD Ports Collection or the binary pkg repository, services are registered in /etc/rc.conf via sysrc(8), and firewall rules are written in pf.conf(5) syntax. This tutorial stays entirely within the standard base + ports approach […]

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How to Configure SSL/TLS on Nginx on FreeBSD 15 — step-by-step FreeBSD 15 tutorial on Progressive Robot

How to Configure SSL/TLS on Nginx on FreeBSD 15

Introduction Deploying configure ssl/tls on nginx on a FreeBSD 15 machine differs from Linux in several important ways: packages come from the FreeBSD Ports Collection or the binary pkg repository, services are registered in /etc/rc.conf via sysrc(8), and firewall rules are written in pf.conf(5) syntax. This tutorial stays entirely within the standard base + ports […]

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How to Manage Kernel Parameters with sysctl on RHEL 10 — step-by-step RHEL 10 tutorial on Progressive Robot

How to Manage Kernel Parameters with sysctl on RHEL 10

Introduction RHEL 10 ships with a stable, security-hardened base that makes deploying manage kernel parameters with sysctl both straightforward and auditable. This tutorial covers the complete procedure for how to Manage Kernel Parameters with sysctl on RHEL 10, including dnf module streams where applicable, systemd unit management, and the firewalld rules required for network-facing services. […]

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Common Problems 114455

RHEL 9: chronyd Not Synchronizing System Time

🟡 Medium   ⏱ 5–30 min  Last verified: 14 July 2026 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & Cross-Refs References & Further […]

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