DNS

Common Problems 111845

Windows Server 2022 AD Kerberos SPN Lookup Fails with KDC Errors – Fix & Prevention

🟠 High   ⏱ 5–30 min  Last verified: 20 October 2022 Affected versions: Windows Server 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 […]

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How to Configure Nginx as a TCP/UDP Load Balancer on FreeBSD 12 — step-by-step FreeBSD 12 tutorial on Progressive Robot

How to Configure Nginx as a TCP/UDP Load Balancer on FreeBSD 12

Introduction This guide explains how to Configure Nginx as a TCP/UDP Load Balancer on FreeBSD 12 on FreeBSD 12. 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 […]

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How to Install Rust with rustup on Debian 11 — step-by-step Debian 11 tutorial on Progressive Robot

How to Install Rust with rustup on Debian 11

Introduction How to Install Rust with rustup 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. […]

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Common Problems 121578

OOM Killer Terminating Critical Application Processes

🔴 Critical   ⏱ 5–30 min  Last verified: 19 October 2022 Affected versions: Debian 9 📖 ~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 Use Podman with Buildah on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Install and Use Podman with Buildah on RHEL 9

Buildah is a daemonless, rootless command-line tool for building OCI-compliant container images — without requiring a running Docker daemon or root privileges. On RHEL 9, Buildah ships as a first-class tool alongside Podman, and the two integrate tightly: images built with Buildah appear immediately in Podman’s local image store. Buildah’s fine-grained API lets you build […]

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Common Problems 111709

Windows Server 2022 — RDP Fails with NLA Error After Certificate Renewal — Fix & Prevention

🟠 High   ⏱ 5–30 min  Last verified: 19 October 2022 Affected versions: Windows Server 2022 📖 ~1 min read Table of contents Symptom & Impact Quick Checks Deep Diagnosis Primary Fix Verification Prevention & Hardening Symptom & Impact Remote Desktop sessions fail before credential prompt with NLA or authentication package errors. Administrative access is […]

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How to Install and Configure Fail2ban on Debian 11 — step-by-step Debian 11 tutorial on Progressive Robot

How to Install and Configure Fail2ban on Debian 11

Introduction This guide explains how to Install and Configure Fail2ban 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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Ubuntu 22.04 — ldns — multiple vulnerabilities (2 CVEs) — patch and remediation guide — diagnosis and fix on Ubuntu 22.04

Ubuntu 22.04 — ldns — multiple vulnerabilities (2 CVEs) — patch and remediation guide

🟢 Low   ⏱ 5–15 min  Last verified: 19 October 2022 Affected versions: Ubuntu 22.04 (jammy) 📖 ~4 min read  •  Source: Ubuntu Security Notice USN-5257-2 Related CVEs: CVE-2020-19860 CVE-2020-19861 Upstream summary: USN-5257-1 fixed several vulnerabilities in ldns. This update provides the corresponding update for Ubuntu 20.04 ESM and Ubuntu 22.04 ESM. Original advisory details: […]

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