🌐 Overview: DNS (Domain Name System)¶

This page serves as a central entry point for the entire DNS infrastructure and zone management.

1. The Most Important Record Types¶

2. DNS Function¶

Name resolution is physically separated into public and internal services.

2.1 The Recursive Path¶

sequenceDiagram
    autonumber
    participant Client as Client (OS / Browser)
    participant Resolver as Local DNS Resolver

 Note over Client,Resolver: Recursive resolution<br/>(The DNS resolver handles the work)

    Client->>Resolver: What is the IP address of server.example.com?
    activate Resolver
    Note right of Resolver: Searches the local cache...<br/>...or queries the DNS hierarchy (iteratively)
    Resolver-->>Client: The IP address is 192.168.1.50
    deactivate Resolver

2.2 The Iterative Approach¶

sequenceDiagram
    autonumber
    participant Resolver as DNS Resolver
    participant Root as Root Nameserver (.)
    participant TLD as TLD Nameserver (.com)
    participant Auth as Authoritative Nameserver

    Note over Resolver,Auth: Iterative resolution (step-by-step through the tree)

 Resolver->>Root: Who is responsible for "server.example.com"?
    Root-->>Resolver: I don't know. But here is the IP of the ".com" TLD server.

    Resolver->>TLD: Who is responsible for "server.example.com"?
    TLD-->>Resolver: I don’t know. But ask the authoritative server for "example.com".

 Resolver->>Auth: What is the IP address of "server.example.com"?
    Auth-->>Resolver: That’s my zone! The IP is 192.168.1.50.

3. Diagnostics & Standard Commands (CLI)¶

Quick dig commands for troubleshooting directly in the terminal.

4. Related Pages¶