ping通但打不开网页
网页出现：
The proxy server is refusing connections Firefox is configured to use a proxy server that is refusing connections. Check the proxy settings to make sure that they are correct.
一般是代理服务器不能访问。
解决方法：
“选项 -> 高级 -> 网络 -> 设置”查看一下代理服务器设置是否正确。