Hi everyone,
My name is bolajiwey, i am an architect by training and not so new to Linux. I work in a corporate environment where the dominant operating system is microsoft windows.
I have been partially successful in connecting any linux box i configured to the internet via the ISA server in our corporate network.
I said partially because i can browse using Mozilla firefox once i set up my proxy under connection settings-manual proxy configuration.
However, irrespective of the distribution (SUSE,REDHAT,FEDORA,MEPIS) or the desktop (KDE OR GNOME), i cannot do the underlisted through the same ISA server:

1.Perform system updates using YUM,YAST or red carpet
2. Chat online using Kopete or GAIM
3.Browse the internet with Konqueror

I believe a lot of people who work in corpoarte environments like mine have the same issues with ISA, if anyone has been able to solve the problem, please let me know.
thank you

Have you set the proxy variable in the environment on the Linux machines? For example:
You can set this in the /etc/bashrc or /etc/profile to make it available system-wide.

Update: You'll need to export it as well:

export HTTP_PROXY

How did you manage to do that? I have been trying to do the same thing with SUSE 10.1 but keep getting "Firefox is configured to use a Proxy server that can't be found".

Generally, that means that you've specified an incorrect host name, the proxy port is missing or incorrect, or the authentication is not valid.

It might be a problem with the authentication on the ISA server. It's probably setup for ntlm authentication.

Talking as a windows user:
The only browser I know that can handle it (next to IE) is Firefox. Try Opera and it will not work. I think you're running into the same problem with your apps.

Maybe this page is of some help.

Thanks for all the solutions proferred, i am presently running SUSE 10.0 and i have tried setting up the proxy using YAST as root, it still gives me the error 'Proxy authentication required', even though i used a valid proxy server name, user name and password to set up the proxy. These same settings do not give me issues on windows XP.

I am thinking,does anyone know how to configure authentication sources such that when i try logging in to the proxy via YAST, it sends the authentication as NTLM? I know if i am able to get it right using YAST on SUSE, i will stop having these issues.

Also, as i said earlier, i can still browse using firefox, for Vulplus, all you need do is go to the edit-->preferences menu , click on the general menu and select 'connection settings', specify the correct ISA or proxy server name(if you are using ISA,you may need to specify the domain name suffix for the proxy server e.g arklinux.vulplus.com, instead of just the machine name, or better still, put in the IP address of the proxy server). Next ,don't forget the port number, if your proxy is configured to connect to the internet using a different port from 8080, find out from the administrator.

I need to get a solution to this, because it may just be one of the reasons users are sceptical of moving to linux. You have a situation whereby you can't run system updates, chat or get RSS feeds because you are using linux and the proxy is ISA. The better solution would have been to yank out ISA and get a better proxy software such as SQUID or Astaro linux to do the job, but how do you do that when you are not the boss?
expecting your suggestions,

thank you

Yes, this worked perfectly for daily-updates of my debian behind a ntlm-proxy.
http://ntlmaps.sourceforge.net/

looks like the ISA server is working as advertised