DNS Archives - ITFROMZERO - Share tobe shared!

Configuring DNS-over-TLS with systemd-resolved on Linux: Boost Security for DNS Resolution

By IT From Zero October 8, 2026

A guide to configuring DNS-over-TLS and DNSSEC with systemd-resolved on Linux — encrypting DNS queries to block ISP eavesdropping and man-in-the-middle attacks. Includes a 5-minute quick start, DNSSEC configuration, per-link DNS, and debugging tips from real production experience.

Network

How to Configure DNSSEC on BIND9: Digitally Signing and Validating DNS Records to Prevent Cache Poisoning

By IT From Zero October 5, 2026

A step-by-step guide to configuring DNSSEC on BIND9: generate KSK/ZSK keys, enable automatic zone signing, and synchronize DS records to prevent DNS cache poisoning.

Network

Configuring DNS Split-Horizon with BIND9: The IP “Splitting” Trick for LAN and Internet

By IT From Zero September 2, 2026

Learn how to configure DNS Split-Horizon with BIND9 to distribute internal IPs for LAN and Public IPs for the Internet. Optimize speed and reduce Firewall load.

Network

CoreDNS on Linux: Replacing Bind9 for Smoother Microservices Operations

By IT From Zero August 14, 2026

CoreDNS is the perfect alternative to Bind9 in the Microservices era. Learn how to install, configure Corefile, and optimize plugins for production systems.

Security

SPF, DKIM, and DMARC: The ‘Atomic Trio’ for 100% Email Inbox Delivery

By IT From Zero May 14, 2026

Don't let your emails disappear into the Spam folder. Here is a detailed guide on configuring SPF, DKIM, and DMARC to secure your domain and enhance sender reputation for IT pros.

Ubuntu

Install and Configure AdGuard Home on Ubuntu to Block Ads and Secure DNS for Your Entire Local Network

By IT From Zero April 25, 2026

AdGuard Home is a DNS sinkhole you install on Ubuntu to block ads and tracking for every device on your LAN — including Smart TVs and IoT devices. This guide walks through each step: freeing port 53, installing the binary, configuring upstream DoH, adding blocklists, and pointing your router's DNS to AdGuard Home.

Network

DNS Configuration on Linux: Permanently Fix Settings Being Lost After Reboot

By IT From Zero April 15, 2026

Tired of losing DNS settings in /etc/resolv.conf after every reboot? This guide shows you how to properly configure DNS on Linux using Netplan, nmcli, and systemd-resolved for long-term stability.

Network

Setting Up a DNS Server with Bind9 on Ubuntu/Debian

By IT From Zero February 28, 2026

A step-by-step guide to setting up an internal DNS server with Bind9 on Ubuntu/Debian: installation, forward and reverse zone files, forwarder and ACL configuration, testing, and troubleshooting. Written from real-world experience managing an office network.