We're currently using Lighttpd with FastCGI to serve PHP to our clients. We recently added load balancing through RackSpace Cloud to help us handle our traffic however, the client's IP is now the load balancer IP. All traffic is through HTTPS.
We've enabled mod_extforward and have tried all different configuration for with using our LB IP and the different headers ("X-Forwarded-For","Forwarded-For","X-Cluster-Client-Ip") and we cannot seem to get this to work!
Any ideas? Thank you!
Best Answer
If you're using Rackspace's Cloud Load Balancers, you won't be able to get the client's IP address over SSL.
For plain HTTP, the balancers can do intelligent things (the "service unavailable" page, X-Forwarded-for, etc.) However, the load balancers can't do anything other than ferry bytes between the client and server over HTTPS, because, without the private key, there's no way to modify the stream (other than making it invalid.)
Someone asked this question on the Rackspace forums a little while ago.