CURL request does not pass IP address

Question

I've created the following file on my destination server: test.php

<? 
    echo json_encode($_SERVER);

When CURLing to this file from my computer(mac):

curl -XPOST '<myurl>/test.php'

the 'REMOTE_ADDRESS' that is returned is the external IP of my computer(as expected). However, when CURLing to this file from my source server(through ssh, linux), exactly the same command, the 'REMOTE_ADDRESS' is always the IP of my destination server. Somehow, the CURL command on my source server does not expose its IP on the other side.

There is no 'X_FORWARDED_FOR' property in the $_SERVER variable.

Is this some CURL configuration i'm missing on my source server?