I have a server with 6 ip addresses added via cPanel. I'm having troubles limiting the IP address my clients can use as an outgoing IP address in their PHP script. Some of them are running proxies and using the CURLOPT_INTERFACE to switch from the server IP address to other clients IP address.
I'm not sure how to limit CURLOPT_INTERFACE to just the server IP address or bind it to the server + the clients dedicated IP address...