dnsmasq disable forwarders

Disabling DNS forwarders in dnsmasq can be essential for various configurations, especially when you want to manage DNS queries locally without relying on upstream DNS servers. This guide will cover how to disable DNS forwarding in dnsmasq, along with some potential scenarios and additional configuration options you might find useful.

Understanding dnsmasq Forwarders

dnsmasq is a lightweight DNS forwarder and DHCP server designed for small networks. By default, dnsmasq resolves DNS queries by forwarding them to upstream DNS servers. However, you may want to disable or limit this functionality for various reasons, such as improved privacy, network performance, or when using a custom DNS resolver.

Steps to Disable DNS Forwarding

Here’s a step-by-step guide to disable DNS forwarding in dnsmasq:

1. Modify Configuration File

The primary method to disable DNS forwarders is by modifying the dnsmasq configuration file, usually located at /etc/dnsmasq.conf. To disable DNS forwarding:

1. Open the configuration file in your favorite text editor:

   sudo nano /etc/dnsmasq.conf
   

2. Look for or add the following line:

   port=0
   

   Setting the port to 0 disables dnsmasq's DNS service completely, which stops it from listening for DNS requests and forwarding them.

2. Disable DNS Feature

If you do not want to disable DNS service entirely but want to control how dnsmasq resolves addresses, you could try these alternatives:

• Disable forwarding to upstream DNS servers: Add the line:

  no-resolv
  

  This ensures that dnsmasq does not use any external DNS servers. Instead, it will require that you provide all the necessary DNS records for local resolution.

• Set a fixed list of local servers (if required): You can specify local DNS servers directly using:

  server=<local-server-ip>
  

3. Restart dnsmasq

After saving your changes to dnsmasq.conf, ensure you restart the service to apply the changes:

sudo systemctl restart dnsmasq

4. Verify Configuration

You can verify that DNS forwarding is disabled by checking the service logs or running a DNS query to see if it responds without forwarding:

dig @localhost example.com

If configured correctly, it should not try to resolve through external DNS servers if no-resolv is set.

Additional Considerations

• Network Interfaces: If you plan to limit DNS on a specific interface, consider specifying the interface in the configuration for finer control:

  interface=<your-interface>
  

• Client-Specific Settings: For networks requiring custom DNS settings, dnsmasq can be configured per client using dhcp-option settings.

Conclusion

Disabling forwarders in dnsmasq provides more control over DNS resolution within your network, which is particularly useful in scenarios where privacy or performance is a concern. By carefully managing your configuration, you can create efficient and secure local DNS resolutions that fit your network’s specific needs.

For further reading on managing dnsmasq, consult the official documentation on ArchWiki or community forums such as OpenWRT and Netgate.