mod_extforward: Lighttpd Log Clients Real IP Behind Reverse Proxy / Load Balancer

I've setup 5 lighttpd web servers behind Nginx based reverse proxy / load balancer to distribute load for busy e-commerce website. However, all web server nodes putting my load balncers two IP address in access log file. How do I force lighttpd to log a real IP (public IP) address of all client computers visiting our website?

Read answer to: "mod_extforward: Lighttpd Log Clients Real IP Behind Reverse Proxy / Load Balancer"