Networking

How to Configure Kerberos Authentication on RHEL 7 — step-by-step RHEL 7 tutorial on Progressive Robot

How to Configure Kerberos Authentication on RHEL 7

How to Configure Kerberos Authentication on RHEL 7 Kerberos is a network authentication protocol that uses symmetric-key cryptography to allow clients and servers to prove their identity to each other securely without transmitting passwords over the network. It is the backbone of authentication in Active Directory environments and is natively supported across Linux through MIT […]

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How to Configure Database Connection Pooling with PgBouncer on RHEL 7 — step-by-step RHEL 7 tutorial on Progressive Robot

How to Configure Database Connection Pooling with PgBouncer on RHEL 7

How to Configure Database Connection Pooling with PgBouncer on RHEL 7 Every PostgreSQL client connection spawns a backend process on the server, consuming approximately 5–10 MB of RAM for its working memory and adding overhead to the process scheduler. Applications that open hundreds of short-lived connections — such as PHP scripts, Node.js workers, or microservices […]

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Common Problems 118949

Ubuntu 14.04 LTS – DNS resolution fails after network changes

🟠 High   ⏱ 5–30 min  Last verified: 30 November 2021 Affected versions: Ubuntu 14.04 LTS Ubuntu 14.04 Ubuntu 14.04.6 📖 ~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 Configure pf Firewall Rules on FreeBSD 13 — step-by-step FreeBSD 13 tutorial on Progressive Robot

How to Configure pf Firewall Rules on FreeBSD 13

Introduction Deploying configure pf firewall rules on freebsd 13 on a FreeBSD 13 machine differs from Linux in several important ways: packages come from the FreeBSD Ports Collection or the binary pkg repository, services are registered in /etc/rc.conf via sysrc(8), and firewall rules are written in pf.conf(5) syntax. This tutorial stays entirely within the standard […]

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How to Deploy a Flask App with Gunicorn on FreeBSD 13 — step-by-step FreeBSD 13 tutorial on Progressive Robot

How to Deploy a Flask App with Gunicorn on FreeBSD 13

Introduction This guide explains how to Deploy a Flask App with Gunicorn on FreeBSD 13 on FreeBSD 13. 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 Capsicum […]

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Common Problems 117409

Ubuntu 20.04 no sound output on speakers or headset

🟡 Medium   ⏱ 5–30 min  Last verified: 29 November 2021 📖 ~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 Monitor Nginx with Prometheus on FreeBSD 13 — step-by-step FreeBSD 13 tutorial on Progressive Robot

How to Monitor Nginx with Prometheus on FreeBSD 13

Introduction This guide explains how to Monitor Nginx with Prometheus on FreeBSD 13 on FreeBSD 13. 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 Capsicum for fine-grained […]

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How to Configure Windows Server 2019 Container Security — step-by-step Windows Server 2019 tutorial on Progressive Robot

How to Configure Windows Server 2019 Container Security

How to Configure Windows Server 2019 Container Security Securing Windows containers on Windows Server 2019 involves hardening the container runtime, securing container images, isolating workloads, controlling network access, and monitoring for anomalous behavior. The default Docker installation is functional but not hardened for production use. This guide covers the key security controls available for Windows […]

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How to Deploy Applications with Docker Compose on RHEL 8 — step-by-step RHEL 8 tutorial on Progressive Robot

How to Deploy Applications with Docker Compose on RHEL 8

Docker Compose simplifies running multi-container applications by defining every service, network, and volume in a single docker-compose.yml file. Instead of typing long docker run commands for each container, you declare the desired state and let Compose handle the orchestration. On RHEL 8 with Docker CE installed, Docker Compose V2 ships as a plugin and is […]

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How to Set Up NFS Server on FreeBSD 13 — step-by-step FreeBSD 13 tutorial on Progressive Robot

How to Set Up NFS Server on FreeBSD 13

Introduction How to Set Up NFS Server on FreeBSD 13 is a core administration task for any FreeBSD 13 server operator. FreeBSD 13 ships with the 15.0-RELEASE kernel, ZFS as the default root filesystem, Capsicum capability sandboxing improvements, and an updated ports tree. Unlike Linux distributions, FreeBSD uses rc(8) for service management, pf for packet […]

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