DNS

Common Problems 120531

Debian 11 – nftables Rules Missing After Reboot – Persistent Firewall Setup

🟠 High   ⏱ 5–30 min  Last verified: 19 May 2026 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 & […]

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How to Install and Configure ufw Firewall on Debian 11 — step-by-step Debian 11 tutorial on Progressive Robot

How to Install and Configure ufw Firewall on Debian 11

Introduction This guide explains how to Install and Configure ufw Firewall on Debian 11 on Debian 11 Bullseye. Debian Bullseye uses systemd for service management, nftables as the underlying packet filter (with ufw or iptables front-ends still available), and AppArmor for mandatory access control. Every command is designed for a minimal Debian 11 install with […]

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How to Set Up Alertmanager with PagerDuty and Slack Integration on RHEL 7 — step-by-step RHEL 7 tutorial on Progressive Robot

How to Set Up Alertmanager with PagerDuty and Slack Integration on RHEL 7

Prometheus generates alerts, but it is Alertmanager that handles routing, deduplication, grouping, and delivery to your notification channels. Without a properly configured Alertmanager, even the most thorough alerting rules in Prometheus are useless — they fire into the void. Integrating Alertmanager with both PagerDuty and Slack gives you a two-tier notification strategy: high-severity incidents page […]

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Common Problems 117110

Ubuntu 22.04 LTS Fail2ban Not Banning Attackers Due to Journal Backend Misconfig

🟡 Medium   ⏱ 5–30 min  Last verified: 20 May 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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Common Problems 117039

Ubuntu 22.04 LTS – OpenSSL certificate chain errors break wget and curl

🟠 High   ⏱ 5–30 min  Last verified: 20 May 2026 Affected versions: Ubuntu 22.04 LTS Ubuntu 22.04 Ubuntu 22.04.4 📖 ~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 […]

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How to Install .NET 6 SDK on Debian 11 — step-by-step Debian 11 tutorial on Progressive Robot

How to Install .NET 6 SDK on Debian 11

Introduction Debian 11 Bullseye is built around the ethos of stability and free software. Setting up install .net 6 sdk on debian 11 on Bullseye leverages the same proven Debian packaging system that powers millions of servers worldwide, while benefiting from the latest upstream releases included in the Bullseye freeze. Follow each step carefully and […]

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How to Configure auditd System Auditing on Debian 11 — step-by-step Debian 11 tutorial on Progressive Robot

How to Configure auditd System Auditing on Debian 11

Introduction Deploying configure auditd system auditing on 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 […]

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Common Problems 120472

Debian 11: dpkg interrupted and requires manual configure

🟠 High   ⏱ 5–30 min  Last verified: 19 May 2026 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 & […]

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How to Install and Secure phpMyAdmin on Debian 11 — step-by-step Debian 11 tutorial on Progressive Robot

How to Install and Secure phpMyAdmin on Debian 11

Introduction This guide explains how to Install and Secure phpMyAdmin on Debian 11 on Debian 11 Bullseye. Debian Bullseye uses systemd for service management, nftables as the underlying packet filter (with ufw or iptables front-ends still available), and AppArmor for mandatory access control. Every command is designed for a minimal Debian 11 install with the […]

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Common Problems 116963

Ubuntu 22.04 LTS – snap downloads stall or hang indefinitely – Fix & Prevention

🟡 Medium   ⏱ 5–30 min  Last verified: 19 May 2026 Affected versions: Ubuntu 22.04 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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