X-Forwarded-For Question

[Beta_Tester Profile]

Hi,

I am looking for a product which will allow us to utilise the X-Forwarded-For header for inbound web requests on our Forefront TMG array (we utilise the same servers for reverse and forward proxy).

I have installed a trial version of ISAPI Rewrite and edited httpd.ini file to include the following additional entries:-

RewriteCond %REMOTE_ADDR (.+)
RewriteHeader X-Forwarded-For: (?!.).* $1

However, this will provide the X-Forwarded-For header for outbound web requests as well as inbound - we have been asked to restrict this to inbound requests only.

Any ideas???

Thanks very much!!!!

[HeliconAndrew]

Hello,

there're several additional questions to you:

a) Is it ISAPI_Rewrite 2 or 3? httpd.ini is supported only be v2, not 3. While this topic is in v3.
b) Hsve you installed ISAPI_Rewrite on TMG or IIS?

Regards
Andrew

[Beta_Tester Profile]

Sorry for posting this in the wrong forum. The version I am testing is actually version 2, as I am using the ISA/TMG version of the product.

[HeliconAndrew]

Well, correct we if I'm wrong...

This rule works for you, but 2 ways, while you need to make it work only one way.
So my guess is that we need to add another condition to narrow it down.

Regards
Andrew

[Beta_Tester Profile]

Hi,

Yes, that is correct. I am trying to work out what the condition would be to implement this...

Thanks v. much.

[HeliconAndrew]

We've researched TMG variables and found the following:

Code: Select all

IS_REVERSE_PROXY
A string containing TRUE or FALSE, indicating if the request is a forward proxy or reverse proxy request.

I think this could be a clue, just not sure which value would you need...

Regards
Andrew

[Beta_Tester Profile]

Hi,

I have now tried to implement this by putting the following into the httpd.ini file:-

RewriteCond %IS_REVERSE_PROXY (True)
RewriteCond %REMOTE_ADDR (.+)
RewriteHeader X-Forwarded-For: (?!.).* $1

Unfortunately this doesn't work. I have tried values of true and false and neither of them work.

If I take the first RewriteCond line out, it works fine.

Any ideas?????

Thanks!

[Beta_Tester Profile]

Hi,

I have now tried to implement this by putting the following into the httpd.ini file:-

RewriteCond %IS_REVERSE_PROXY (True)
RewriteCond %REMOTE_ADDR (.+)
RewriteHeader X-Forwarded-For: (?!.).* $1

Unfortunately this doesn't work. I have tried values of true and false and neither of them work.

If I take the first RewriteCond line out, it works fine.

Any ideas?????

Thanks!

Worked it out in the end. I had to use a different TMG variable:-

RewriteCond %REVERSE_PROXY 1