XDCC

Limitations in the original DCC protocol prevented the transfers of very large files, or groups of files. XDCC was developed to allow batching of files together, and requesting/sending those files to others.{{cite book|author1=Sachs, Marcus |author2=Piccard, Paul |year=2005 |url=https://books.google.com/books?id=ZZU95ZdQ908C&pg=PA387 |title=Securing IM and P2P Applications for the Enterprise |publisher=Syngress |page=387|isbn=978-1-59749-017-7 |access-date=2013-04-09|display-authors=etal}}

XDCC was initially a script written in 1994 for ircII{{cite book | last = Charalabidis | first = Alex | title = The Book of IRC: The Ultimate Guide to Internet Relay Chat | edition = 1st | date = 1999-12-15 | publisher = No Starch Press | location = San Francisco, California | isbn = 1-886411-29-8 | pages = [https://archive.org/details/bookofirc00char/page/219 219 – 220] | chapter = DCC: File Servers and XDCC | chapter-url = https://archive.org/details/bookofirc00char/page/219 }} by Xabi. This script extends the ircII DCC command. Now XDCC refers to IRC bots running file sharing programs in general.{{cite book | last = Wang | first = Wallace | title = Steal this File Sharing Book | edition = 1st | date = 2004-10-25 | publisher = No Starch Press | location = San Francisco, California | isbn = 1-59327-050-X | page = [https://archive.org/details/stealthisfilesha00wang/page/66 66] | chapter = Instant Messaging and Online Chat Rooms: Downloading files from IRC | chapter-url = https://archive.org/details/stealthisfilesha00wang/page/66 }} XDCC bots serve one or more usually large files for download using the DCC protocol. XDCC is commonly employed in distributing illegal content, such as warez releases of software, music, and movies.

Unlike peer-to-peer transfers, XDCC servers are often hosted on connections with very high upstream bandwidth, sometimes in excess of 100 Mbit.{{cite web|url=https://nipponsei.minglong.org/packlist/archive/|title=Nipponsei - Music Fresh From Japan|access-date=27 September 2015|archive-date=28 September 2015|archive-url=https://web.archive.org/web/20150928011553/https://nipponsei.minglong.org/packlist/archive/|url-status=live}} Often FTP servers are also running on the XDCC servers to facilitate uploading of materials to them. Many XDCC servers run on security compromised computers.{{cite web|url=https://www.cs.rochester.edu/~bukys/host/tonikgin/EduHacking.html|title=XDCC|archive-url=https://web.archive.org/web/20180208122753/https://www.cs.rochester.edu/~bukys/host/tonikgin/EduHacking.html|access-date=6 June 2020|archive-date=2018-02-08}}

A stand-alone IRC client such as mIRC or HexChat is required to use the DCC protocol. In order to receive files, the software has to be properly configured, otherwise downloads will be rejected by the software.{{cite web|url=http://theloadguru.com/how-to-configure-mirc/|title=How To Configure mIRC For Downloading|work=The Load Guru|access-date=27 September 2015|archive-date=17 January 2023|archive-url=https://web.archive.org/web/20230117211702/https://www.theloadguru.com/how-to-configure-mirc/|url-status=live}}

To use XDCC, one can send a private message (query) or send a CTCP command to a bot, using an IRC client. The user can ask a bot what files it has by private messaging "xdcc list" to the bot. However, this feature is often disabled as to not attract too much attention. When a user wants to download a packet or file from a bot, the user would type something such as "xdcc send #" to the bot. The bot will either start sending the user the packet or the bot will place the user in a queue, and force the user to wait their turn. Some channels have special rules, for example requiring the user to join a second channel within a certain amount of time after starting the download to avoid interruptions.{{cite web|url=http://theloadguru.com/mirc-guide-troubleshooting/|title=How To Download With mIRC: Troubleshooting|work=The Load Guru|access-date=27 September 2015|archive-date=17 January 2023|archive-url=https://web.archive.org/web/20230117211647/https://www.theloadguru.com/mirc-guide-troubleshooting/|url-status=live}}

Addons exist, such as XDCCKlipper (for mIRC) which listen to adverts listed in a channel by the bots and save them to a separate window to facilitate easier browsing and allow users to view the status of a bot (speed, queues, slots etc.).

{{Reflist}}

• [http://xa.bi/files/irc/xdcc.3.3.0b.irc xdcc script 3.3.0 beta] - The original XDCC script
• [https://web.archive.org/web/20040225095053/http://www.cs.rochester.edu/~bukys/host/tonikgin/EduHacking.html Security Paper featuring XDCC] on the Internet Archive

{{IRC topics}}

Category:IRC

Category:File sharing

Category:Warez

Category:Internet terminology

Category:Protocols related to IRC