The HTTP request includes a non-supported header on ISA 2004

Good day

I've got an ISA 2004 server that is used for internet access only, when I try to connecto to a certain URL through the ISA, I get the following error:

Technical Information (for support personnel)
Error Code: 502 Proxy Error. The HTTP request includes a non-supported header. Contact your ISA Server administrator. (12156)
IP Address:
Date: 29/06/06 10:12:34 AM
Server: ismid01
Source: proxy

Where can I see what the Header is that the URL is using and how do I allow this Header to go through ISA

Any Help would be appreciated

Who is Participating?

Improve company productivity with a Business Account.Sign Up

Leon FesterConnect With a Mentor Senior Solutions ArchitectCommented:
Check the Alerts tab under the monitoring section in ISA Server Management console.

You should see the exact reason for the header being rejected.
Leon FesterSenior Solutions ArchitectCommented:
I've seen that same error on my server when I enabled compression after loading SP2.

Disabling the compression for request to the external network, in the General Configuration settings, seems to have resolved my issues.
FlorisvddAuthor Commented:
I've disabled the compression for External, no diffrence, I removed all selected applications types aswell, still the same
Get your problem seen by more experts

Be seen. Boost your question’s priority for more expert views and faster solutions

FlorisvddAuthor Commented:
Thank you, I see there is a patch (KB 915045) for this issue on ISA 2004 Std and Ent editions
Leon FesterSenior Solutions ArchitectCommented:
Excellent! Now I also know that :) I've been waiting for a fix, but haven't been monitoring it...
FlorisvddAuthor Commented:
Apparently there is a re-release of this patch, not sure about the number though
okay here is a 100% resolution from microsoft

Surely will resolve your issue


Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.