How to Download Files Using Specific DNS Ubuntu

This article explains how to download files on Ubuntu while forcing the use of a specific DNS resolver. You will learn the exact command-line flags required for tools like wget and curl to bypass system default settings. This method is useful for troubleshooting network issues or accessing resources restricted by local DNS configurations.

Using Wget with a Custom DNS Server

The most common command for downloading files in Ubuntu is wget. To specify a DNS resolver, use the --dns-servers flag. This option allows you to define one or more IP addresses for the DNS lookup without changing your system network settings.

The basic syntax is:

wget --dns-servers=IP_ADDRESS URL

For example, to download a file using Google’s public DNS server (8.8.8.8), run:

wget --dns-servers=8.8.8.8 https://example.com/file.zip

You can specify multiple DNS servers by separating them with commas. This ensures a fallback if the primary resolver fails:

wget --dns-servers=8.8.8.8,1.1.1.1 https://example.com/file.zip

Note that this feature requires wget version 1.20 or newer, which is standard in Ubuntu 20.04 and later.

Using Curl with a Custom DNS Server

If you prefer using curl, the process is similar. The curl command also supports the --dns-servers option to dictate which nameservers handle the domain resolution.

The syntax for curl is:

curl --dns-servers IP_ADDRESS -O URL

To download a file using Cloudflare’s DNS (1.1.1.1), execute:

curl --dns-servers 1.1.1.1 -O https://example.com/file.zip

The -O flag tells curl to save the file using its remote name. Like wget, this command performs the DNS lookup independently of your /etc/resolv.conf configuration.

Why Use a Specific DNS Resolver

Using these commands allows you to bypass ISP-level DNS filtering or caching issues. It is particularly helpful when a domain resolves incorrectly on your local network but works correctly via public DNS. This method provides a quick way to test connectivity without altering global network configurations.