使用squid代理時出現“The requested URL could not be retrieved”

問題：
當使用代理訪問網站時出現以下錯誤：
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The requested URL could not be retrieved

While trying to retrieve the URL: http://linkhelp.clients.google.com/tbproxy/lh/fixurl?

The following error was encountered:

    Unable to determine IP address from host name for linkhelp.clients.google.com

The dnsserver returned:

    Timeout

This means that:

 The cache was not able to resolve the hostname presented in the URL.
 Check if the address is correct.

Your cache administrator is root.
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解決方案：
這是由於Proxy 伺服器機器的DNS配置問題，Proxy 伺服器機器不能找到指定url的ip地址導致。檢查/etc/resolv.conf檔案配置是否正確，如不正確添加正確的配置資訊，比如說：
nameserver ###.###.###.###
nameserver ###.###.###.###
可以配置多個DNS server。
重新啟動squid服務。