IP address of fastcgi server?

Hi All,

We're doing some profiling and one of the parameters we'd like to get is the IP address of the fastcgi (in this case php-fpm) server that processed the request.  PHP $_SERVER['server_addr'] returns the external address of the nginx server per our fastcgi configuration:

fastcgi_param  SERVER_ADDR        $server_addr;

Is this correct behavior? is there a way to get the local address of the server processing the php request?

Thanks