<?php
echo "当前页面服务器IP地址为：";
echo $_SERVER["SERVER_ADDR"];
echo "<br />";
echo "当前客户端IP地址为：";
echo $_SERVER["REMOTE_ADDR"];
echo "<br />"; //www.2cto.com
echo "当前端口为：";
echo $_SERVER["SERVER_PORT"];
?>
原文：http://www.cnblogs.com/youxianyen/p/6008911.html