Networking

How to Set Up Two-Factor Authentication with Google Authenticator on Debian 11 — step-by-step Debian 11 tutorial on Progressive Robot

How to Set Up Two-Factor Authentication with Google Authenticator on Debian 11

Introduction Debian 11 Bullseye is built around the ethos of stability and free software. Setting up set up two-factor authentication with google authenticator 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 […]

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Common Problems 116978

Ubuntu 22.04 LTS – snap install fails due to store connectivity errors – Fix & Prevention

🟡 Medium   ⏱ 5–30 min  Last verified: 24 October 2022 Affected versions: Ubuntu 22.04 LTS (Jammy) 📖 ~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 […]

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How to Deploy an Application to Kubernetes on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Deploy an Application to Kubernetes on RHEL 9

Deploying an application to Kubernetes involves creating a set of resource objects that describe the desired state of the application — Kubernetes continuously works to make the actual state match this desired state. The core resources for most applications are: a Deployment (manages the desired number of running pod replicas and handles rolling updates), a […]

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How to Configure IPSec VPN on IBM AIX 7.2 — step-by-step IBM AIX 7.2 tutorial on Progressive Robot

How to Configure IPSec VPN on IBM AIX 7.2

Introduction IBM AIX 7.2 is the latest release of IBM’s enterprise-grade UNIX operating system, running on IBM Power Systems hardware. Known for its reliability, security, and performance in mission-critical environments, AIX 7.2 introduces enhanced virtualization, security hardening, and cloud integration features. This guide covers how to configure ipsec vpn on ibm aix 7.2 on IBM […]

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How to Configure GitHub Actions Self-Hosted Runner on Debian 11 — step-by-step Debian 11 tutorial on Progressive Robot

How to Configure GitHub Actions Self-Hosted Runner on Debian 11

Introduction Deploying configure github actions self-hosted runner 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 You […]

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Common Problems 116998

Ubuntu 22.04 LTS – SSH connection refused after reboot – Fix & Prevention

🟠 High   ⏱ 5–30 min  Last verified: 22 October 2022 Affected versions: Ubuntu 22.04 LTS (Jammy) 📖 ~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 […]

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Common Problems 114569

Postfix Cannot Send Mail Due To DNS Or Relay Policy

🟡 Medium   ⏱ 5–30 min  Last verified: 22 October 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 […]

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How to Configure AppArmor for Nginx on Debian 11 — step-by-step Debian 11 tutorial on Progressive Robot

How to Configure AppArmor for Nginx on Debian 11

Introduction This guide explains how to Configure AppArmor for Nginx 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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How to Configure Kerberos Authentication on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Configure Kerberos Authentication on RHEL 9

Kerberos is a network authentication protocol that uses symmetric-key cryptography and a trusted third party — the Key Distribution Center (KDC) — to authenticate users and services without transmitting passwords over the network. RHEL 9 ships the MIT Kerberos implementation and it integrates tightly with SSH, NFS, and other network services through GSSAPI. This tutorial […]

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Common Problems 118599

Ubuntu 16.04 LTS Chrony Not Syncing Due to Firewall Policy

🟡 Medium   ⏱ 5–30 min  Last verified: 21 October 2022 Affected versions: 16.04 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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