In this section, we explore the world of programming, algorithms, networks, and infrastructure
This article provides a complete and structured explanation of the /var/cpanel/cpanel.config file, the core configuration file that stores nearly all Tweak Settings options in cPanel & WHM. It explains how the file works, how dynamic values behave, how caching is handled, and includes a categorized list of the most important keys with their descriptions, default values, and related WHM interface locations.
This article explains Upgrade Blockers in cPanel & WHM—issues that prevent the system from installing or upgrading to a newer version. It covers standard checks, version‑specific blockers, multi‑stage upgrade behavior, required pre‑upgrade conditions, and solutions for the most common blockers across versions 110 to 130.
How to Resolve CIFS Backup Permission Errors and Remote Transport Issues in cPanel & WHM
This article explains how cPanel & WHM automatically replaces weak, expiring, invalid, or revoked SSL certificates with free Let’s Encrypt certificates. It covers replacement conditions, the automated process, examples, how to disable automatic replacement, certificate management options, and troubleshooting issues such as CAA restrictions and missing FQDN hostnames.
This article explains how DNS caching works, why clearing your DNS cache may be necessary, and how to clear it on Windows, macOS, ChromeOS, Ubuntu, and other Linux systems. It also provides a complete step-by-step guide to configuring Reverse DNS (PTR records) in WHM, including system requirements, creating reverse DNS zones, editing PTR records, and testing your configuration.
This article explains how to identify the registrar of a domain, how to list domains with DNSSEC enabled on a server, and how to modify the hosts file on macOS, Linux, and Windows systems. These procedures help administrators manage domain ownership, DNS security, and local DNS overrides for testing and development.
This article explains how nameservers work in a cPanel & WHM environment and provides a complete step-by-step guide to configuring nameserver software, setting default nameservers, assigning IP addresses, creating A/AAAA records, and adding A records for the server hostname. It is designed for administrators who want to properly configure DNS for their hosting infrastructure.
This article explains what a Reverse Trust relationship is in a cPanel & WHM DNS cluster, why it is required, and how servers use API tokens to authenticate and exchange DNS records securely. It also outlines the importance of mutual trust between all servers in the cluster.
This guide explains how DNS clusters work in cPanel & WHM, including requirements, recommended structures, trusted IP configuration, direct and intermediary linking, performance considerations, and the importance of Reverse Trust relationships. It also covers how to manage API tokens and how DNSOnly servers fit into a cluster.
This guide explains how the rpm.versions system in cPanel & WHM manages RPM and DEB packages, how to safely override default package states, how the directory hierarchy works, and how to use update_local_rpm_versions to avoid YAML formatting issues. It includes practical examples and best‑practice warnings.
This guide covers essential troubleshooting and quick-repair tools available in cPanel & WHM, including Autofixer, cloud-hosted hostname fixes, restoring database grants, using the scl utility for PHP management, and diagnosing Perl/CGI script issues.
This article explains how ModSecurity 3 works in cPanel & WHM, how to install and configure it for Apache or NGINX, key differences from ModSecurity 2, and how to use the experimental NGINX Standalone web server. It includes configuration paths, warnings, and compatibility notes for production environments.
