Öncelikle IIS Advanced Logging modülünü indirmek gerekiyor. Link

Bunun dışında IIS’e yeni bir Filter eklereyerek sorunsuz bir şekilde alınabiliyor.

Buradaki önemli nokta, en tepeden vermeye çalıştığınız da bazen çalışmayabliyor. Hangi site üzerinde yapacaksanız ona tıklayıp default kuralı clone yapın. Sonra da kendi istediğiniz parametreleri ona ekleyin.

A – IIS 7 & later :

Microsoft do now have a solution – it’s called IIS Advanced Logging. This is an installable IIS feature and can be downloaded here. Once installed on the IIS server, you’ll see an extra option called ‘Advanced Logging’ for the sites in IIS.

Once installed, follow the steps below to add the X-Forwarded-For log field to IIS:

1. From your Windows Server 2008 or Windows Server 2008 R2 device, open IIS Manager
2. From the Connections navigation pane, click the appropriate server, web site, or directory on which you are configuring Advanced Logging. The Home page appears in the main panel
3. From the Home page, under IIS, double-click Advanced Logging
4. From the Actions pane on the right, click Edit Logging Fields
5. From the Edit Logging Fields dialog box, click the Add Field button, and then complete the following:
-in the Field ID box, type X-Forwarded-For
-from the Category list, select Default
-from the Source Type list, select Request Header
-in the Source Name box, type X-Forwarded-For
-click the OK button in the Add Logging Field box, and then click the OK button in the Edit Logging Fields box
6. Click a Log Definition to select it. By default, there is only one: %COMPUTERNAME%-Server. The log definition you select must have a status of Enabled
7. From the Actions pane on the right, click Edit Log Definition
8. Click the Select Fields button, and then check the box for the X-Forwarded-For logging field
9. Click the OK button
10. From the Actions pane, click Apply
11. Click Return To Advanced Logging
12. In the Actions pane, click Enable Advanced Logging

Now, when you look at the logs the client IP address is included.

B – IIS 6 :

Unfortunatey the Microsoft solution mentioned above is not available for IIS 6. luckily there are a number of solutions available to address this limitation – some that cost money and others that have been released as open source. One excellent example that we’ve tested with our products is F5′s X-Forwarded-For ISAPI filter. It’s avaialable in both in 32 & 64 bit versions.

1. Download the zipped archive from here and extract to an appropriate folder
2. Navigate to the relevant version (32 or 64 bit)
3. Copy F5XForwardedFor.dll to a suitable location on your server, e.g. C:ISAPIfilters
4. Make sure you have ISAPI Filters enabled on your IIS server
5. Open IIS Manager, right-click the site and select Properties
6. Select the ISAPI Filters tab
7. Click ‘add’, then in the popup enter a suitable name and select the DLL file stored in step 3
8. Restart your website

That’s it – you should now start seeing the IP address of the client PC’s in your IIS logs rather than the IP of the load balancer.