BitTorrent (.torrent) Primer - File Sharing on the Internet

In a recent thread, mention was made of downloading files from the Internet via a "torrent". This is a brief introduction to BitTorrent as both a technology and a piece of software.

And no primer is complete without referencing Wikipedia.
BitTorrent - Wikipedia

TLDR:
BitTorrent is a way to get a file from the Internet by downloading slices of the file from multiple different sources and re-assembling the full file locally. It lets you leverage the speed of multiple sources to download the file faster than "normally" while not costing the "provider" of the file a ton of money for bandwidth.

Personal clients of choice (ALL legitimate clients are free - NEVER pay for a BitTorrent client):
uTorrent - µTorrent - a (very) tiny BitTorrent client
qBittorrent - qBittorrent Official Website
Transmission - Transmission

Detail:
First, what is BitTorrent?
First - BitTorrent is a protocol used to transfer information on the internet. Like HTTP or FTP or e-mail, it has a defined set of criteria (ports, packet size, etc) that are agreed upon and well documented.
Second - BitTorrent is a file sharing technology that uses the BitTorrent protocol to share files, typically large files, across the internet. The BitTorrent technology allows for multiple people to have the exact same file (and I do mean EXACTLY the same) and another person can download discreet pieces of the file from many sources and assemble it locally to get their copy of the file.
Third - BitTorrent is a piece of software that acts as both a client and a server. BitTorrent is kind of like "kleenex" and "band-aid" in that BitTorrent is a company, but there are many bittorrent clients.

So, BitTorrent is a distributed file sharing technology where people download files and in many cases re-share those same files, also called seeding. Originally this general technology was used to pirate software and music. Napster, BearShare and LimeWire are some examples of all but defunct distributed file sharing applications. Napster is still a going concern but they had to radically change their "business model" and become "legitimate".

You participate on the BitTorrent network as a client/server by downloading files and then sharing them back out, even without having completed the file. Since you can download slivers of the file for re-assembly, you can also share those slivers as soon as you have downloaded them and ensured they aren't corrupted.

Someone who shares files on the network is referred to as a "seeder" because you are seeding the file.

Someone who downloads is referred to as a client.

Someone who ONLY downloads and disconnects as soon as they are done downloading or has configured their client not to seed is referred to as a "leecher"...for obvious reasons.

To get started, you need the client (links at the top of this post). I use uTorrent on Windows and qBitTorrent and Transmission on Linux because they are already available for Fedora.

Install is really easy
Windows: Run the executable and pay just a tiny bit of attention. Make sure you install the application but uncheck any additional software installs. Any extra software is NOT required and the last time I used it on Windows the install didn't try to drop any software but just pay attention to what you are clicking. That's it...done...next you will run the software.
Linux (RedHat/Fedora): From a prompt, run the following command to install without downloading ahead of time.

• Fedora (any supported version): sudo yum install qbittorrent (or ktorrent or rtorrent)
• Fedora (18 and above): sudo dnf install qbittorrent (or ktorrent or rtorrent)

Linux (Debian/Ubuntu/Mint): I don't run mint, I'll update this later.
Mac: I don't run Mac, I'm gonna have to update this later.
IOS/Android: Install the client from your App Store.

Using it can take a little bit of work
The biggest hurdle you may run into with using BitTorrent is finding content...at first. Once you know where to look, content ceases to be an issue. Be warned, there are torrent search sites that constantly catalog what is out there for download (it's one giant distributed network and not secret by any stretch of the imagination) so there's a LOT of content to download...about anything and everything...yes, that too. Be careful what you search for, you might get a surprise what turns up.

The key, however, is to get a .torrent file. This is basically a descriptor of the content you actually want to download. Don't try to view it or edit it, it won't work. What it does, however, is look on the giant shared drive that is the Internet for the anyone on the BitTorrent network sharing that file and, if it finds it, starts downloading it from as many people as possible, little bits at a time. It allows people with limited bandwidth to give back to the network in small chunks and when enough people are sharing, you can download VERY large files in a matter of minutes, and nobody has to pay a ton of money for bandwidth.

Once you find the .torrent file, using it depends on how you found it. If you use a torrent search service, you likely are on a web page that has something called a "Magnet Link". The icon is...a magnet. The purpose of the magnet link is to launch the torrent client and load the torrent file automatically, rather than having you download the file, launch the client and then find and import the torrent file. It's just a time saver, don't fear the magnet link.

If, however, you are already in possession of the .torrent file, you will need to manually open your client, and open/import the torrent file. Each client displays things a little differently and if requested we can throw up some additional posts on each client. Generally, it's "File -> Open" and then determine where to save the files.

Once it's up and running, wait a few minutes and you should see the counter start increasing as you begin downloading (and possibly uploading) the pieces of the file you are looking for.

Once the download is complete, locate the file and use it as appropriate (read, run, view, whatever).

If you are willing to "give back", leave the client running for a while to help seed the file.

Warnings:
If you move the file after download, but leave the client open and/or don't remove the torrent from your client, it will try to download again the next time you launch the client. If you aren't going to share, be sure to remove the torrent from the window so it doesn't keep uploading and/or try to download again. Be sure to only remove the torrent, not the "torrent and files", otherwise it will pull the torrent out of your client and also delete what you just downloaded (unless it's been moved).

You might also find that you can't download because your network firewall is preventing some part of the BitTorrent client traffic. Troubleshooting is really beyond the scope of this post but can be addressed at a later time if there is enough interest or need.

 

Running a BitTorrent client on Linux

All of the BitTorrent clients on Linux are very similar in function with the primary differences being to the interface. I will expand this post for individual clients as I get screenshots created. All of the screenshots are from a Fedora Linux desktop, but the interface should be consistent across Linux distributions. For ALL distributions, clicking on a "Magnet Link" will either ask you what you want to use to open the link, or open the associated program, depending on how the OS is configured. Either way, once opened, it will be at step 4 of any of the walk-throughs below.

qBittorrent

1. Launch qBittorrent from whatever menuing system you use.
2. Click on File -> Add Torrent File
3. Browse to the location of the .torrent file, select it and click Open
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4. The torrent will register with your client, search for anyone offering the file or any part of it you don't already have, and begin downloading. By default, all torrents will download to your "Downloads" directory, into a folder with the same name as the torrent.
   
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5. Notice in the screenshot above, that if you select the torrent, in this case tails-amd64-3.1 (in green), it populates some additional detail in the bottom half of the window. This is useful when a torrent "contains" multiple files and allows you to track the status of each component of the torrent.
6. Once the torrent is complete, you can continue to seed, or close the torrent client. If you are going to move the file(s) you have downloaded and/or not seed the torrent for others, you should remove the torrent by selecting the torrent and clicking Edit -> Delete. Do NOT click the checkbox unless you also want to delete the file(s) you just downloaded. Deleting the torrent from the client only removes it from the client itself and does not delete the .torrent file from your computer. You can use the .torrent file again if necessary.
   
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Transmission
Transmission is a no-frills BitTorrent client. None of the pretty interface that qBittorrent has, but it's also light weight with a lower system footprint.

1. Launch Transmission from whatever menuing system you use.
2. Click on File -> Open
3. Browse to the location of the .torrent file, select it and click Open
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4. Transmission will prompt you for a destination. Browse to wherever you want to save the downloaded files and click Open
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5. Unlike qBittorrent, there is little information displayed. You can get additional information by right-clicking the torrent and selecting Properties which will bring up a new tabbed window with most of the same detail that other clients show in the main window.
6. Once the torrent is complete, you can continue to seed, or close the torrent client. If you are going to move the file(s) you have downloaded and/or not seed the torrent for others, you should remove the torrent by selecting the torrent and clicking Torrent -> Remove. This simply removes the torrent from the client but does nothing to the .torrent file or the downloaded files. To remove the downloaded files as well, click Torrent -> Delete Files and Remove. You can use the .torrent file again if necessary.
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Running a BitTorrent client on Windows

Coming soon. Installing Windows 7 on a VM for screenshots.

 

Interesting choice of topic DL....

.tor rules for old people:

1. Proxy. If you are a US citizen - this is wise.
2. Do not download anything that is zipped or .rar
3. Do not download any .exe - ever.
4. If your ISP has data caps, ALWAYS close your torrent program when not in use.
5. Share in moderation - a 1:1 ratio is MORE than adequate.

 

Not going to argue this point because I agree, but like a Ford Fiesta, while not owning one is the best course of action it's not available to everyone for whatever reason.

I'm not accusing you of this attitude, but rather than leaving those who still run Windows out to dry, I'm including that population in the how to.

 

No argument and perhaps you missed the fact that I'm running on Linux and have to build a windows VM to take the screenshots. I've been a proponent of Linux since slackware was a 2 floppy image download.

You also missed where I said I wasn't accusing you of the attitude and chose to take exception with it.

Let's kill this side of the discussion though and or move it to PM. This is a how to thread and not the operating system equivalent of a political thread.

Mods, I'm fine killing this entire diversion from my standpoint.