DNS

Common Problems 115587

firewalld Rich Rules Override Expected Service Access

🟡 Medium   ⏱ 5–30 min  Last verified: 25 April 2022 📖 ~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 […]

Read more
How to Install and Configure IIS on Windows Server 2012 R2 — step-by-step Windows Server 2012 R2 tutorial on Progressive Robot

How to Install and Configure IIS on Windows Server 2012 R2

How to Install and Configure IIS on Windows Server 2012 R2 Internet Information Services (IIS) 8.5 ships with Windows Server 2012 R2 and is the most widely deployed web server on the Microsoft platform. IIS 8.5 includes significant improvements over earlier versions: dynamic IP restrictions, enhanced logging, ETW tracing for real-time diagnostics, application initialisation (warm-up), […]

Read more
How to Upgrade from Debian 10 to Debian 11 — step-by-step Debian 11 tutorial on Progressive Robot

How to Upgrade from Debian 10 to Debian 11

Introduction Deploying upgrade from debian 10 to debian 11 on a Debian 11 Bullseye machine is straightforward thanks to Debian’s policy-compliant packaging. Unlike rpm-based distributions, Debian stores configuration helpers in /etc/default/, uses update-rc.d for older init scripts, and provides dpkg-reconfigure for interactive package configuration. This tutorial stays on the systemd path throughout. Prerequisites Ensure Debian […]

Read more
How to Monitor Kubernetes with Prometheus and Grafana on RHEL 7 — step-by-step RHEL 7 tutorial on Progressive Robot

How to Monitor Kubernetes with Prometheus and Grafana on RHEL 7

How to Monitor Kubernetes with Prometheus and Grafana on RHEL 7 Operating a Kubernetes cluster without monitoring is like running a production database without logs — you will only know something is wrong after an outage has already started. Prometheus is the de facto standard for Kubernetes metrics collection, using a pull-based model where it […]

Read more
Common Problems 120601

Debian 11 – Severe Clock Drift Breaks TLS and Kerberos – Chrony Stabilization

🟠 High   ⏱ 5–30 min  Last verified: 24 April 2022 Affected versions: Debian 11 📖 ~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 & […]

Read more
Common Problems 116977

Ubuntu 22.04 SSH Login Delays Caused by Reverse DNS Lookup

🟡 Medium   ⏱ 5–30 min  Last verified: 24 April 2022 📖 ~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 […]

Read more
How to Install Amanda Network Backup on Debian 11 — step-by-step Debian 11 tutorial on Progressive Robot

How to Install Amanda Network Backup on Debian 11

Introduction How to Install Amanda Network Backup on Debian 11 is a fundamental operation for any administrator maintaining a Debian 11 Bullseye server. Debian 11 Bullseye ships with the Linux 6.12 kernel, updated toolchains, and a fully refreshed package archive — meaning version numbers, configuration file paths, and some dependency chains differ from Debian 11. […]

Read more
AlmaLinux 8 — ldns — vulnerability — patch and remediation guide — diagnosis and fix on AlmaLinux 8

AlmaLinux 8 — ldns — vulnerability — patch and remediation guide

🟡 Medium   ⏱ 10–30 min  Last verified: 25 May 2026 Affected versions: AlmaLinux 8 📖 ~4 min read  •  Source: AlmaLinux ALSA ALBA-2019:3490 Upstream summary: For detailed information on changes in this release, see the AlmaLinux Release Notes linked from the References section. Table of contents Symptom & Impact Environment & Reproduction Root Cause […]

Read more
How to Configure Kubernetes RBAC on CentOS Stream 9 — step-by-step CentOS Stream 9 tutorial on Progressive Robot

How to Configure Kubernetes RBAC on CentOS Stream 9

Introduction How to Configure Kubernetes RBAC on CentOS Stream 9 on CentOS Stream 9 provides administrators with a robust, enterprise-ready workflow that integrates cleanly with systemd, SELinux, firewalld, and the modern AppStream module system. In this tutorial we will walk through every step required, from package installation to verification, so that the resulting configuration is […]

Read more
CHAT