设置Apache使用内部代理服务器(代理链？)

Question

在重定向到外部站点之前，我需要通过内部代理服务器将请求路由到Apache，设置如下：

Browser Request --> Apache --> Internal Proxy Server --> External Site

在没有代理服务器的情况下，我使用作为代理处理的重写完成了重定向(P)

RewriteRule ^/somepath/(.*) http://www.externalsite.com/$1 [P,QSA,L]

我找到了setting up apache behind a forward proxy，它看起来是我想要设置的，并建议我尝试以下指令：

ProxyPass /somepath/ http://www.externalsite.com/
ProxyPassReverse /somepath/ http://www.externalsite.com/
ProxyRemote  http://www.externalsite.com/ http://internal.proxy.ip.addy:8080

当我设置它时，我得到了503和以下Apache日志条目：

[Thu Apr 11 07:47:14 2013] [debug] mod_proxy_http.c(1973): proxy: HTTP: serving URL http://www.externalsite.com/somefile.html
[Thu Apr 11 07:47:14 2013] [debug] proxy_util.c(2011): proxy: HTTP: has acquired connection for (www.externalsite.com)
[Thu Apr 11 07:47:14 2013] [debug] proxy_util.c(2067): proxy: connecting http://www.externalsite.com/somefile.html to www.externalsite.com:80
[Thu Apr 11 07:47:14 2013] [debug] proxy_util.c(2193): proxy: connected http://www.externalsite.com/somefile.html to internal.proxy.ip.addy:8080
[Thu Apr 11 07:47:14 2013] [debug] proxy_util.c(2444): proxy: HTTP: fam 2 socket created to connect to www.externalsite.com
[Thu Apr 11 07:47:35 2013] [error] (OS 10060)A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.  : proxy: HTTP: attempt to connect to internal.proxy.ip.addy:8080 (www.externalsite.com) failed

代理服务器日志中没有记录任何内容，如果我在浏览器中显式设置代理服务器并加载该externalsite.com，我就知道代理服务器可以工作

有什么想法吗？

Answer 1

最终在连接到代理时出现vmware IP地址问题...上面的指令似乎可以正确地将apache代理到代理服务器。