Yahoo Messenger and Internet Proxies

May 12, 2009

3 comments  

I hate proxies but they seem necessary in the Corporate world. Getting all the websites, programs, widgets, etc working as people want can cause much pain and suffering.

This is a simple post, but hopefully it'll save someone a few hours of frustration.

We have a group that has to use Yahoo! Messenger for chat. So I put them on our web filter/proxy, allowing the Yahoo IM access. (Note, our proxy requires NTLM/Active Directory authentication to allow traffic). Those not using Yahoo's client (like those using Pidgin) connected fine. But the official Yahoo client seemed like it wasn't passing the Windows Authentication to the proxy and not connecting. Setting the client's proxy settings to Direct Connection did not work; Yahoo was still pulling Internet Explorer's proxy settings.

After a few hours of searching, I came across this Microsoft KB article: How to Set Up Yahoo Messenger to Use Only Integrated Authentication on Your ISA Server Computer. In the article, it advises that you set your Internet Explorer settings to enable "Use HTTP 1.1 through proxy connections".

Apparently Yahoo Messenger client doesn't send a keep-alive header in it's NTLM request, thus not keeping itself authenticated. Telling it to use HTTP 1.1 forces this, since the keep-alive header is default in 1.1.

Check out the Microsoft article (linked above) for more information, but this simple checkbox fixed the issues for my users. It's not JUST for ISA; I'm not using ISA and it worked for me.