服务器网站总报错“ERROR the requested URL could not be retrieved”解决办法

服务器网站总报错“ERROR the requested URL could not be retrieved”
ERROR

The requested URL could not be retrieved

While trying to retrieve the URL: http://bbs.mjmh.cn/forum-3-1.html

The following error was encountered:

Read Timeout
The system returned:

[No Error]
A Timeout occurred while waiting to read data from the network. The network or server may be down or congested. Please retry your request.

Your cache administrator is webmaster. 
Generated Thu, 30 Aug 2012 08:47:45 GMT by lygdcache (squid/2.7.STABLE9-20110824)

[解决办法]
重启服务器
[解决办法]
能ping通80端口吗
[解决办法]
服务是否当掉了。