If you have a installation of OpenACS that is behind a proxy you will soon realize some stuff will break:

* Installation of modules from OpenACS repository
* News Agregator
* Any application using ns_httpopen, ns_sock...

In order to fix this you have to change two files:

* config.tcl
* [AOLSERVER]/modules/tcl/http.tcl

Changing your server configuration

Go to the section ns/parameters and add these lines under the section:

ns_param proxy your-cache.server
ns_param proxy_port xxxx

Changing the proc ns_httpopen

In the file [AOLSERVER]/modules/tcl/http.tcl go to the line

set fds [ns_sockopen -nonblock $host $port]

And change it to

set proxy [ns_config ns/parameters proxy $host]
set proxy_port [ns_config ns/parameters proxy_port $port]
set fds [ns_sockopen -nonblock $proxy $proxy_port]
set uri http://$host$uri

Now if you restart your server it will work just fine.

Thanks to Stefan Vogel for the fix [1].

[1] http://www.mail-archive.com/aolserver@listserv.aol.com/msg06933.html