Networking

Common Problems 119036

Ubuntu 14.04 LTS – certificate verification fails for outbound HTTPS – Fix & Prevention

🟠 High   ⏱ 5–30 min  Last verified: 17 September 2020 Affected versions: Ubuntu 14.04 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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Common Problems 115532

Postfix mail queue stuck and undelivered

🟡 Medium   ⏱ 5–30 min  Last verified: 17 September 2020 📖 ~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 YaST on SLES 15 — step-by-step SUSE Linux Enterprise 15 tutorial on Progressive Robot

How to Configure YaST on SLES 15

Introduction This tutorial covers How to Configure YaST on SLES 15 on SLES 15. SLES 15 (SUSE Linux Enterprise Server 16) is SUSE’s enterprise-grade Linux distribution. It uses the zypper package manager, AppArmor for mandatory access control, and systemctl for service management. Step 1 — Launch YaST yast Step 2 — Use YaST from the […]

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Common Problems 114944

RHEL 8 chronyd Time Drift and NTP Sync Failure

🟡 Medium   ⏱ 5–30 min  Last verified: 17 September 2020 📖 ~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 112473

Windows Server 2019 — DHCP NACK storms after VLAN resegmentation create widespread endpoint disconnects — Fix & Prevention

🟡 Medium   ⏱ 5–30 min  Last verified: 17 September 2020 Affected versions: Windows Server 2019 📖 ~2 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 OpenTelemetry Collector on Debian 10 — step-by-step Debian 10 tutorial on Progressive Robot

How to Configure OpenTelemetry Collector on Debian 10

Introduction Debian 10 Buster is built around the ethos of stability and free software. Setting up configure opentelemetry collector on debian 10 on Buster leverages the same proven Debian packaging system that powers millions of servers worldwide, while benefiting from the latest upstream releases included in the Buster freeze. Follow each step carefully and the […]

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Common Problems 118125

Ubuntu 18.04 LTS – Certbot renewal fails because port 80 is in use – Fix & Prevention

🟡 Medium   ⏱ 5–30 min  Last verified: 16 September 2020 Affected versions: Ubuntu 18.04 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 Limit Container Resources with cgroups on Debian 10 — step-by-step Debian 10 tutorial on Progressive Robot

How to Limit Container Resources with cgroups on Debian 10

Introduction Deploying limit container resources with cgroups on debian 10 on a Debian 10 Buster 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 Before […]

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Common Problems 118627

Ubuntu 16.04 rsyslog High CPU Usage from Repeated Parse Errors

🟡 Medium   ⏱ 5–30 min  Last verified: 15 September 2020 📖 ~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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