Configuring internet connection behind Microsoft ISA proxy


[malberts] The solutions and steps described here were arrived at after playing around with settings for many days for somebody else's computer. As such I do not yet have a definite guide and I cannot verify the settings because it does not apply to my computer or network. If your internet proxy uses Microsoft ISA Server and you got this to work, please add to or update this guide.

Who needs this?

If your internet connection requires the use of a Microsoft ISA Server proxy.

If you are unsure, ask your ISP if the proxy is managed by a Microsoft ISA Server.

If you are still unsure, you can try to deduce this from some error messages such as:

407 Proxy Authentication Required ( The ISA Server requires authorization to fulfill the request. Access to the Web Proxy filter is denied. )

If your ISP supplies you with a username in the form of "SOMETHING\username" then you might be using such a proxy.

How to get the internet working?

Trisquel 5.5 started using GNOME 3 and currently has no GUI to set proxy information. Older versions of Trisquel had a GNOME 2.3 utility to set proxy information. These instructions have only been tested with Trisquel 5.5 and this guide assumes that you are using the same version.

The solution comprises two utilities:

  • proxydriver
  • cntlm

proxydriver is a script that detects when a connection is made with NetworkManager and updates proxy settings accordingly. This is needed because the NetworkManager applet does not expose any proxy settings.

It is not in the Trisquel repository but can be downloaded from SourceForge. It is released under the GPLv3 license.

cntlm sends the correct information needed to authenticate you against the ISA proxy server.

It is in the Trisquel repository but if you do not have internet access you will have to download it directly from Trisquel's online package list.

Both packages can be installed with:

 sudo dpkg -i package_name.deb

where package_name.deb should be replaced with the name of the file you downloaded.








06/22/2012 - 22:01
03/21/2014 - 07:27