My preferred application for downloading ISO files securely is aria2c which has the ability to download both from http/ftp web sites and also from torrent swarms. This provides two benefits, firstly the fastest download speed that is available and secondly ensuring that the ISO file does not contain any corruptions.
Even if an ISO file has been downloaded using some other method, and fails the md5sum check, it can be recovered using aria2c without a full download. Only the corrupt segments will need to be re-downloaded.
In those instances where a torrent file does not already exist, it is possible to create and download a torrent file for your target ISO using a free service from
http://burnbit.com/burn. Just enter the URL for the target ISO there, wait a few minutes, and then download the torrent file to use, either for an original download or a recovery download of an ISO that has failed the md5sum check.
Example : --
Code:
aria2c -c http://www.proindi.de/zevenos/ZevenOS-Neptune/Neptune3.iso
This will download the ISO file from its original source or multiple mirrors.
Code:
aria2c --check-integrity Neptune3.iso-Burnbit.torrent
This will check the integrity of the completed download and if it fails the verification check will download any segments that are in error, saving a complete download that may potentially fail again.
Here's how to use both the torrent and the ftp server together : --
Code:
aria2c -T Neptune3.iso-Burnbit.torrent http://www.proindi.de/zevenos/ZevenOS-Neptune/Neptune3.iso
2013-04-02 11:59:20.489791 NOTICE - DHT: listening to port 6981
2013-04-02 11:59:20.512445 NOTICE - BitTorrent: listening to port 6915
*** Download Progress Summary as of Tue Apr 2 12:00:20 2013 ***
=====================================================================================================================================================================
[#1 SIZE:50.4MiB/1,811.9MiB(2%) CN:5 SEED:0 SPD:825.1KiBs ETA:36m25s]
FILE: /media/data/MyDownloadedISOFiles/ZevenOS/Neptune3/Neptune3.iso
---------------------------------------------------------------------------------------------------------------------------------------------------------------------
[#1 SIZE:52.1MiB/1,811.9MiB(2%) CN:5 SEED:0 SPD:819.2KiBs ETA:36m39s]
There is extensive help in the man file
or on-line.
http://aria2.sourceforge.net/
Paul
