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Firewalling out Off Campus Connections

Due to the restrictions and threats of disconnections by ITS on campus, it is worth thinking about blocking all external connections to DC++ on campus. This does NOT guarantee safety from ITS on campus, but it will stop you using any external bandwidth and hopefully keep you a bit more under the radar. Almost all the time, connections between on campus and off campus people are impossible due to the traffic shaper, so even without any kind of firewall rules in place you should not be transferring to or from somebody off campus. However, the connection attempts will be detected, logged and subsequently blocked by the traffic shaper even if you do not see any transfers in DC++ (although sometimes connections slip through the traffic shaper causing even more problems for you).

Firewalling off campus out is intended as an extra layer of security, and doesn't guarantee your safety from ITS. We do believe that is is by far the best thing you can do though and recommend it to everybody.

Guides for blocking blocking external connections to DC++ in various firewalls and operating systems are below. If you are looking for a quick and easy firewall to block connections, then we recommend one of Comodo, Sygate or Kerio as these are light on system resources and are unlikely to interfere with your computer as a whole.


Windows Firewall

First you will most likely need to disable any DC++ rules in the firewall, then you can either run the commands above, or get the install.bat file below which will run them all at once. So all you need to do is download the scripts right click on the appropriate one and 'run as Administrator'.

Also ensure that the DC++ executable file is located at "C:\Users\YourName\DC++\DCPlusPlus.exe". If this is not the case the commands/scripts have to be modified accordingly. If you are using the preconfigured client from this wiki then you will either need to extract it to Program Files or change the rules to reflect the new location of the DCPlusPlus.exe file. If you go to C:\Users\YourName\DC++ you should see the list of files for DC itself (DCPlusPlus.exe, favourites.xml etc etc) and NOT the DC++ and stunnel folders.

READ THIS: Really, you cannot just run these scripts and expect it to work, you have to read the above and make the necessary changes!

Install Firewall Rules

Uninstall Firewall Rules

You can test whether this is working in DC++ itself by going to Help -> About DC++. At the bottom of the window that shows up is a section saying latest version. If this shows some form of error then the external blocking is correctly set up. If it shows a DC++ version number then it is not.

These have been recently modified to allow for changes to the Warwick network. Feedback would be appreciated as to whether they work or not, just ask on the hub if they don't and we'll try to figure it out.

Comodo Personal Firewall 3

(guide produced by Rampage)

Free firewall
Version 3 is Windows Vista compatible

There is also a guide available for Comodo Personal Firewall Version 2.4 here.
You can download Comodo Personal firewall from

Eset Smart Security (NOD32)

(guide produced by Rampage)

Windows Vista compatible, please ask on the hub for someone to test it for you. Guide Needs testing, if you find it is up to scratch please contact astropoint or Rampage and this will be finalised. If something needs editing please contact Rampage.

Kaspersky v7

(guide produced by astropoint)

Kaspersky v8 (2009) seem to have removed alot of the functionality of v7 in regards to specific blocking of applications to certain IP ranges as is required on campus. If anybody can work out how to do it on the newer versions please tell an op and we can try to knock together a guide.

Norton Personal Firewall

(guide produced by astropoint)

Guide was produced for Norton 2005, but the basic structure of the rules etc hasn't changed so should be applicable to more recent versions. However if somebody is willing to help update it somewhat it would be appreciated; contact astropoint.


(guide produced by 2448-1111)

Warning: This puts the whole of the Resnet into the firewall's "Trusted Zone" which is a really bad idea on the whole. So if somebody comes up with a way of allowing IPs JUST to DC++, pm astro/astropoint and I'll try to update the guide.

Windows XP

Due to the coming discontinuation of support for Windows XP, firewall options for this are no longer listed. If you are really desperate then ask and somebody will help you through setting it up (and advise you to upgrade to something else ASAP).



New guide (courtesy of mooo, improved by Rampage)
Original guide (courtesy of xyzzy) This is the original version of the guide. Might be worth reading if the newer one isn't working, or you need some extra help configuring Fedora specific settings.

A guide for setting up the Linux firewall, iptables, to block external connections. (produced by xyzzy originally. Resurrected by mooo)

EiskaltDC++ ipfilter

(Courtesy of Rampage)
EiskaltDC++ is a cross platform client which has an 'ipfilter' module built into the client. This module can be used to block off campus connections or vice versa. This has not been extensively checked so please do report back your findings.


Little Snitch

(guide produced by nish81)

A GUI firewall for MACs that can be used to block external connections. Confirmation this works on other Macs would be useful if somebody wishes to try it.


(guide produced by Rampage)

A simple and fast guide for setting up the Mac OS Firewall, ipfw, to block external connections.

EiskaltDC++ ipfilter

(Courtesy of Rampage)
EiskaltDC++ is a cross platform client which has an 'ipfilter' module built into the client. This module can be used to block off campus connections or vice versa. This has not been extensively checked so please do report back your findings.

Confirm with an Operator to check that the firewall rules are working.

Starting from scratch

If you want to do this from scratch, you need to find how to get your firewall to only allow Resnet IPs ( - ( or and - ( or and the loopback address for stunnel ( and blocking all other IPs from connection.

Conversely you could allow all IPs then block -, -, - and - specifically.

Also, if you do this on a firewall not listed here then please contact an op with at least a basic set of instructions to be uploaded here.

If there are any other problems any of the guides themselves, please contact astropoint/astro on the hub or on the forums and I shall try to correct them. Or, if you feel you can produce a guide for any other firewall, please do so and pass it onto me and I shall upload it onto here.