When using the approach discussed in Technical Note 09-27: IIS and ISAPI ReWrite; if the server you are trying to redirect to is not directly accessible by the client machine (i.e. the web browser cannot contact the destination directly) then you will want to do a Proxy and not a Redirect.

We can get a feel for the basic syntax by looking at the examples from Helicon's website:

Example 1: Running servers behind IIS

Assume we have an internet server running IIS and several corporate servers running other platforms. These servers are not directly accessible from the internet but only from our corporate network. Here is a simple example how to map another server into the IIS site's namespace using proxy flag:

[ISAPI_Rewrite] RewriteProxy /mappoint(.+) http\://sitedomain$1 [I,U]

Using this approach the httpd.conf for the Helicon softweare may look this:

# **** Example Code Start **** # Helicon ISAPI_Rewrite configuration file # Version 3.1.0.79 AllowOverride All RewriteEngine On # begin proxy requests for /server1 to server @ IP .100 RewriteProxy /server1(.+) http\://192.168.1.100$1 [I,U] # end proxy requests for /server1 to server @ IP .100 # begin proxy requests for /server2 to server @ IP .110 RewriteProxy /server2(.+) http\://192.168.1.110$1 [I,U] # end proxy requests for /server2 to server @ IP .110 # begin proxy requests for /server3 to server @ IP .122 RewriteProxy /server3(.+) http\://192.168.1.122$1 [I,U] # end proxy requests for /server3 to server @ IP .122 # **** Example Code End ****

Using the same approach but for sub-domains instead of sub-directories may look like this:

# **** Example Code Start **** # Helicon ISAPI_Rewrite configuration file # Version 3.1.0.79 AllowOverride All RewriteEngine On # Begin Redirect ww1 to 211 RewriteCond %{HTTP_Host} ^ww1\.exampleurl\.org$ RewriteProxy (.*) http\://192.168.1.211/$1 [I] #End Redirect ww1 to 211 # Begin Redirect ww3 to 113 RewriteCond %{HTTP_Host} ^ww3\.exampleurl\.org$ RewriteProxy (.*) http\://192.168.1.113/$1 [I] #End Redirect ww3 to 113 # **** Example Code End ****