This guide will demonstrate how to enable source IP logging on IIS 8.
If using a load balancer or a reserve proxy you will need to configure the device to pass the client IP in the HTTP header.
1. Open up IIS manager and click on the "Default Web Site" and find the Logging feature.
2. Double click Logging, then click Select Fields.
3. Click on Add Field
4. Put in the values as below and select OK, then OK again.
5. Click "Apply" on the right.