Configuring DNS with Dnsmasq 🌐🛠️

Overview Dnsmasq is a lightweight and versatile tool that provides DNS, DHCP, TFTP, and PXE services. It is useful for smaller setups requiring a centralized solution for multiple network services.

Installation and Basic Functionality:

1. Install Dnsmasq:

   • Use the command: sudo apt install dnsmasq.

2. Basic Operation:

   • Default Functionality: Provides a DNS cache for faster query responses.

   • Query DNS: Use the dig command to query DNS. Example:

     dig www.example.com @localhost

Debugging and Advanced Configuration:

1. Run in Debug Mode:

   • Stop Service: sudo service dnsmasq stop

   • Start in Debug Mode: Use the command:

     sudo dnsmasq -d -q

   • Observe Debug Output: Shows detailed logs of DNS queries and responses.

2. Cache Behavior:

   • Initial Query: Forwards to configured DNS servers.

   • Subsequent Queries: Uses cached results.

Authoritative DNS Configuration:

1. Host File Configuration:

   • Create Host File: List IPs and hostnames in a format similar to /etc/hosts.

   • Include File in Dnsmasq:

     sudo dnsmasq -d -q -H /path/to/hosts

2. Query Authoritative Responses:

   • Example Query:

     dig oxygen.local @localhost

   • Responses: Provides authoritative answers for listed hosts.

3. Handling Unknown Queries:

   • Example Query for Non-existent Domain:

     dig hydrogen.local @localhost

   • Behavior: Forwards to external DNS servers if the hostname is not in the local list.

Summary Dnsmasq simplifies DNS management by offering caching and authoritative responses in a single package. It’s easy to set up and configure, making it suitable for small to medium-sized network environments. 🌟🔍