squid装好后，就可以启动了，但其他电脑还不能直接通过这个代理来上网，配置文件里只允许localhost使用这个代理，感觉默认配置文件有点不合理，如果只给本机代理上网，根本没什么意义，或者本机通过本机的代理上网这样更加安全吧？
当你不修改squid.conf，启动squid后，你在另外一台电脑修改浏览器的代理设置，你会得到以下提示
ERROR
The requested URL could not be retrieved
While trying to retrieve the URL: http://www.baidu.com/
The following error was encountered:
Access Denied.
Access control configuration prevents your request from being allowed at this time. Please contact your service provider if you feel this is incorrect.
Your cache administrator is root.