https://my-it-blog.netlify.app/tags/dns/ Recent content in DNS on My IT Journal Hugo en-us Thu, 09 Jul 2026 00:00:00 +0000 https://my-it-blog.netlify.app/posts/secondary-dns-server/ Thu, 09 Jul 2026 00:00:00 +0000 https://my-it-blog.netlify.app/posts/secondary-dns-server/ <h2 id="objective">Objective</h2> <p>Configure a Secondary DNS server that automatically replicates DNS zones from the Primary DNS server using zone transfers (AXFR).</p> <hr> <h2 id="environment">Environment</h2> <ul> <li>Virtualization: VirtualBox</li> <li>OS: ( 1 Primary DNS Server VM + 1 Secondary DNS Server + 1 Web Server VM + 1 Client VM)</li> </ul> <hr> <h2 id="network-topology">Network Topology</h2> <h2 id="dns-tolopogy"><img alt="dns-tolopogy" loading="lazy" src="https://my-it-blog.netlify.app/posts/secondary-dns-server/topology.png"></h2> <h2 id="prerequisites">Prerequisites</h2> <p>This lab builds upon the following previous labs:</p> <ul> <li>Private DNS Infrastructure with BIND9</li> <li>Hosting Multiple Websites on One Server Using Nginx</li> </ul> <p>The following components are assumed to already be configured:</p> https://my-it-blog.netlify.app/posts/private-certificate-authority/ Wed, 08 Jul 2026 00:00:00 +0000 https://my-it-blog.netlify.app/posts/private-certificate-authority/ <h1 id="https-with-nginx-using-a-private-certificate-authority">HTTPS with Nginx using a Private Certificate Authority</h1> <h2 id="objective">Objective</h2> <p>Secure an existing Nginx website using HTTPS and a certificate signed by a private Certificate Authority.</p> <hr> <h2 id="environment">Environment</h2> <ul> <li>Virtualization: VirtualBox</li> <li>OS: ( 1 DNS Server VM + 1 Web Server VM + 1 Client VM)</li> </ul> <hr> <h2 id="network-topology">Network Topology</h2> <p><img alt="dns-topology" loading="lazy" src="https://my-it-blog.netlify.app/posts/private-certificate-authority/dns-topology.png"></p> <hr> <h2 id="prerequisites">Prerequisites</h2> <p>This lab builds upon the Private DNS Infrastructure with BIND9. The following components are assumed to already be configured:</p> <ul> <li>BIND9 installed and running on the DNS server.</li> <li>The company.lab DNS zone created and configured.</li> <li>The zone file (/etc/bind/db.company.lab) already exists.</li> <li>The client is configured to use the internal DNS server (192.168.10.10) via Netplan.</li> <li>DNS resolution between the client and the DNS server has been verified.</li> </ul> <hr> <h2 id="phase-1---verify-dns-resolution">Phase 1 - Verify DNS Resolution</h2> <p>Before enabling HTTPS, verify that DNS resolves the web server correctly.</p> https://my-it-blog.netlify.app/posts/reverse-dns/ Sat, 04 Jul 2026 00:00:00 +0000 https://my-it-blog.netlify.app/posts/reverse-dns/ <h1 id="configuring-reverse-dns-ptr-records-with-bind9">Configuring Reverse DNS (PTR Records) with BIND9</h1> <h2 id="objective">Objective</h2> <p>Extend the existing private DNS infrastructure by configuring Reverse DNS (PTR records). This enables IP addresses to be resolved back to hostnames, complementing the forward lookup zone created in previous labs.</p> <p>By the end of this lab, the DNS server will support both:</p> <ul> <li>Forward lookups (hostname → IP address)</li> <li>Reverse lookups (IP address → hostname)</li> </ul> <hr> <h2 id="environment">Environment</h2> <ul> <li>Virtualization: VirtualBox</li> <li>OS: ( 1 DNS Server VM + 1 Web Server VM + 1 Client VM)</li> </ul> <hr> <h2 id="network-topology">Network Topology</h2> <p><img alt="dns-topology" loading="lazy" src="https://my-it-blog.netlify.app/posts/reverse-dns/dns-topology.png"></p> https://my-it-blog.netlify.app/posts/nginx-virtual-hosts/ Fri, 03 Jul 2026 00:00:00 +0000 https://my-it-blog.netlify.app/posts/nginx-virtual-hosts/ <h1 id="hosting-multiple-websites-on-one-server-using-nginx">Hosting Multiple Websites on One Server Using Nginx</h1> <h2 id="objective">Objective</h2> <p>Host multiple websites on a single web server by combining:</p> <p>DNS (BIND9) Nginx Virtual Hosts (Server Blocks)</p> <hr> <h2 id="environment">Environment</h2> <ul> <li>Virtualization: VirtualBox</li> <li>OS: ( 1 DNS Server VM + 1 Web Server VM + 1 Client VM)</li> </ul> <hr> <h2 id="network-topology">Network Topology</h2> <p><img alt="dns-topology" loading="lazy" src="https://my-it-blog.netlify.app/posts/nginx-virtual-hosts/dns_vhost_topology.png"></p> <hr> <h2 id="prerequisites">Prerequisites</h2> <p>This lab builds upon the Private DNS Infrastructure with BIND9 (3-VM Lab). The following components are assumed to already be configured:</p> <ul> <li>BIND9 installed and running on the DNS server.</li> <li>The company.lab DNS zone created and configured.</li> <li>The zone file (/etc/bind/db.company.lab) already exists.</li> <li>The client is configured to use the internal DNS server (192.168.10.10) via Netplan.</li> <li>DNS resolution between the client and the DNS server has been verified.</li> </ul> <p>In this lab, the existing DNS infrastructure is extended by adding additional DNS records and configuring Nginx virtual hosts to host multiple websites on a single web server.</p> https://my-it-blog.netlify.app/posts/private-dns/ Thu, 02 Jul 2026 00:00:00 +0000 https://my-it-blog.netlify.app/posts/private-dns/ <h1 id="private-dns-infrastructure-with-bind9">Private DNS Infrastructure with BIND9</h1> <h2 id="objective">Objective</h2> <p>Build a private DNS infrastructure using BIND9 where:</p> <ul> <li>A DNS server resolves names in the company.lab domain.</li> <li>A web server hosts a website.</li> <li>A client uses the DNS server to locate and access the web server.</li> </ul> <hr> <h2 id="environment">Environment</h2> <ul> <li>Virtualization: VirtualBox</li> <li>OS: ( 1 DNS Server VM + 1 Web Server VM + 1 Client VM)</li> </ul> <hr> <h2 id="network-topology">Network Topology</h2> <p><img alt="dns-topology" loading="lazy" src="https://my-it-blog.netlify.app/posts/private-dns/dns-topology.png"></p> <hr> <h2 id="phase-1---configure-dns-server">Phase 1 - Configure DNS Server</h2> <h3 id="step-1---install-bind9-and-verify">Step 1 - Install BIND9 and verify</h3> <div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span>sudo apt update </span></span><span style="display:flex;"><span>sudo apt install bind9 bind9-utils dnsutils </span></span><span style="display:flex;"><span>sudo systemctl status named/bind9 </span></span><span style="display:flex;"><span>ss -tulnp | grep 192.168.10.10:53 </span></span></code></pre></div><p><img alt="bind9-status" loading="lazy" src="https://my-it-blog.netlify.app/posts/private-dns/bind9-status.png"> <img alt="verify" loading="lazy" src="https://my-it-blog.netlify.app/posts/private-dns/verify-bind.png"></p> https://my-it-blog.netlify.app/posts/dns-server/ Tue, 05 May 2026 00:00:00 +0000 https://my-it-blog.netlify.app/posts/dns-server/ <h1 id="-dns-lab">🧪 DNS Lab</h1> <h2 id="-objective">📌 Objective</h2> <p>Understand DNS from a systems perpective</p> <hr> <h2 id="-environment">⚙️ Environment</h2> <ul> <li>Virtualization: VirtualBox</li> <li>OS: ( 1 DNS Server VM + 1 Client VM)</li> </ul> <hr> <h2 id="-lab-network-topology">🛠️ Lab Network Topology</h2> <h3 id="-phase-1--direct-dns-no-cache">🧩 Phase 1 — Direct DNS (No Cache)</h3> <p>Client VM -&gt; dnsmasq (192.168.10.10)</p> <p>Used for:</p> <ul> <li>Break #1 (Wrong DNS Server)</li> <li>Break #2 (Wrong DNS Record)</li> </ul> <hr> <h3 id="-phase-2--direct-dns-no-cache">🧩 Phase 2 — Direct DNS (No Cache)</h3> <p>Clint VM -&gt; systemd-resolved (127.0.0.53) [CACHE] -&gt; dnsmasq (192.168.10.10) [DNS SERVER]</p>