Multi-WAN parallel HTTP(S) downloads with Aria2 or Axel on Linux or macOS command line
I currently have multiple WAN connections for my home network. While this works pretty well (and even adds some redundancy), I would much rather prefer a single faster connection. The load balancing router distribute traffic across the WAN interfaces, but does not bond them to a single faster download.
Normally this is not really an issue, but for downloading large files like Linux distribution images it would be an advantage to have a single fast download. Due to it's nature BitTorrent (and other P2P apps) can take full use of the breadth of all connections, but for HTTP this is not (necessarily) the case. Browsers are currently limited to a single download stream, as are common CLI tools like curl and wget.
There are "download manager" utilies available that can download simultaneously with multiple WANs, but I prefer using command line (CLI) applications for downloads. The GNU wget utility is getting support for multiple streams with the upcoming release of wget2, but there are already tools available.
To fully saturate your different WANs from the command line on Linux or macOS (also Windows Subsystem for Linux) there are at least two command line utilities available: Aria2 and Axel. They are stable software and are available for installation using packet managers like apt, brew and yum.
Download Hannah Montana Linux with Axel on Mac
Let's say I want to install Hannah Montana Linux on a MacBook, and I want to do it as fast as I can behind two slow ADSL links. For the example I chose Axel, but Aria2 would work just as fine. The first step is to install Axel using brew packet manager. Fire up your terminal of choice and run:
$ brew install axel
This takes some time as it downloads and installs the axel app on your machine of knowledge. Once this is complete you can proceed straight to downloading the installation image from Tucows:
$ axel -a -n 6 http://www.tucows.com/download/linux/files/hannah_montana_linux_x86_basic_edition.iso
Once this is complete you can continue wiping macOS and replacing it with a proper Operating System.
-- Jani Tarvainen, 12/06/2018