added proxy_ips config item to whitelist reverse proxy servers to use the HTTP_X_FORWARDED_FOR header safely to determine the visitor's IP address
diff --git a/system/application/config/config.php b/system/application/config/config.php
index 58309d8..fae962e 100644
--- a/system/application/config/config.php
+++ b/system/application/config/config.php
@@ -311,6 +311,19 @@
 $config['rewrite_short_tags'] = FALSE;
 
 
+/*
+|--------------------------------------------------------------------------
+| Reverse Proxy IPs
+|--------------------------------------------------------------------------
+|
+| If your server is behind a reverse proxy, you must whitelist the proxy IP
+| addresses from which CodeIgniter should trust the HTTP_X_FORWARDED_FOR
+| header in order to properly identify the visitor's IP address.
+| Comma-delimited, e.g. '10.0.1.200,10.0.1.201'
+|
+*/
+$config['proxy_ips'] = '';
+
 
 /* End of file config.php */
 /* Location: ./system/application/config/config.php */
\ No newline at end of file