Seedboxes are useful when you work with large files over the internet. Although torrents are mis-associated with piracy, the decentralized P2P architecture performs extremely well when large files have to be transferred. Transferring a 20GB file over the Internet using either HTTP or FTP is a practical joke. Torrents are perhaps one of the greatest Internet innovations in the past few decades and have dramatically changed the way we perceive assets on the Internet.

We will be using opentracker to announce torrents and rtorrent to set-up the seed-box. opentracker will take care of announcing the torrents added with rtorrent and rtorrent will be responsible for seeding them to connecting clients.

OpenTracker is a straight-forward torrent tracker. It is light-weight and runs entirely in RAM without using up disk-space. Note that the job of a tracker is to just announce torrents, such that it is not necessary to allocate too many resources to OpenTracker. To set-up OpenTracker, we must first install libowfat0. On Debian, the package is provided by the repositiories and can be installed using aptitude install libowfat-dev libowfat0. Otherwise, the official website suggest checking it out from CVS:

cvs -d :pserver:cvs@cvs.fefe.de:/cvs -z9 co libowfat
cd libowfat
make install
cd ..

The next step is to clone OpenTracker from CVS and install it:

git clone git://erdgeist.org/opentracker
cd opentracker
make
make install

The binary will be placed in /usr/bin/.

Now that we have installed opentracker, the next step is to add a configuration file. This step is actually not necessary because OpenTracker can be configured from the command-line and takes very few parameters. Nevertheless, for the sake of consistency with other system-daemons, it is nice to have a configuration file around that can be easily changed.

We are going to create a new user and group under which OpenTracker will run. This can be easily achieved using:

groupadd opentracker
useradd -g opentracker -G opentracker -d /srv/torrent opentracker
mkdir /srv/opentracker
chown -R opentracker: opentracker /srv/opentracker

this will allow us to use capabilities to restrict access, or even chroot the setup if necessary.

Now, we create the /etc/opentracker.conf file, with the following contents:

listen.udp.workers 4
listen.tcp_udp EXTERNAL_IP:63258
tracker.user opentracker

where:

• EXTERNAL_IP has to be changed to the external IP address that OpenTracker will bind to. This can also be set to 0.0.0.0 to listen on all interfaces.

By default, OpenTracker listens on port 6969 but in this case, we have set the port number to 63258. In doing so, we can bypass some upstream ISP filtering. If we were to use the default setting, 6969 it becomes trivial for an ISP to block incoming connections in case your tracker becomes popular. This does not mean that 63258 cannot be blocked either, but ISPs usually perform some template-based blocking that may filter your tracker. A good port to choose is somewhere over the 61000s because none of those are attributed to any particular service by IANA. The tracker.user setting represents the username under which OpenTracker will run.

Now the init script for OpenTracker can be fetched and added to /etc/init.d/opentracker. After which, we activate OpenTracker so it will be started on reboot:

update-rc.d opentracker defaults

rtorrent is a light-weight console-based torrent client. It is comparable to ctorrent, which is smaller, but rTorrent also provides an interface that can be controlled using key-combos. To install rTorrent in Debian, issue:

aptitude install rtorrent

Additionally, create an user for rTorrent:

groupadd rtorrent
useradd -g rtorrent -G rtorrent -d /srv/rtorrent rtorrent
mkdir /srv/rtorrent
chown -R rtorrent:rtorrent /srv/rtorrent

The next step is to create a directory structure that will hold downloads and an additional directory where we can just drop torrent files so that rTorrent picks them up automatically.

mkdir -p /srv/rtorrent/{downloads,torrents}
chown -R rtorrent:rtorrent /srv/rtorrent/{downloads,torrents}

Now we add a configuration file for rtorrent by editing /srv/torrent/.rtorrent.rc:

directory = /srv/rtorrent/downloads/
schedule = watch_directory,5,5,load_start=/srv/rtorrent/torrents/*.torrent
schedule = untied_directory,5,5,stop_untied=
ip = EXTERNAL_IP
bind = EXTERNAL_IP
port_range = 64050-64100
port_random = yes
check_hash = true
use_udp_trackers = yes
encryption = require,require_RC4,allow_incoming,try_outgoing,enable_retry
dht = auto
dht_port = 6889
peer_exchange = yes

Some of these settings are important, for example:

• EXTERNAL_IP has to be substituted for the external IP.
• port_range has to be changed while making sure that it does not overlap with the listen.tcp_udp of OpenTracker from the previous section.
• The encryption setting is particularly important and the way this is set-up in the configuration file above, it forces encryption on all connections. This is important because most of the problems with slow download speeds are due to the fact that torrent clients are set to not use encryption at all which makes it easier for upstream ISPs to block transfers. This should be left unchanged and configured exactly as shown in the example above.

Now, the way that rTorrent is set-up is that on start-up, it will read all the torrent files placed in /srv/rtorrent/torrents and will automatically queue them up and start downloading to /srv/rtorrent/downloads.

The final step is to install tmux that will allow us to run rTorrent in a multiplexed console so that we can manipulate torrents by accessing rTorrent's interface:

aptitude install tmux

And then download the rtorrent init script and place it in /etc/init.d/rtorrent. After making the appropriate changes, set it to run on boot by issuing:

update-rc.d rtorrent defaults

Now that the set-up is complete, we can start OpenTracker and rTorrent with:

service opentracker restart
service rtorrent restart

and then su to torrent in order to check the torrent status by attaching to the tmux rtorrent session created by the init script:

su torrent
tmux attach-session -t rtorrent

you will be placed in a multiplexed terminal. After toying with rtorrent, you can background the session by hitting the Ctrl+B D key-combo.

Any torrent file placed in /srv/rtorrent/torrents will be automatically added to the queue by rTorrent. A good idea is to use samba share permissions to share both the /srv/rtorrent/downloads and the /srv/rtorrent/torrents folder.