Agent Guides › Web Agent Guide › Protecting Web Applications › Use Web Agents with Proxy Servers › Configure Agents that Sit behind Proxy Servers

Configure Agents that Sit behind Proxy Servers

If a Web Agent will be installed behind a proxy server, you can configure the Web Agent to work with proxy servers using the following parameters:

ProxyTrust

Instructs the Web Agent operating on a destination server to trust the authorizations received by another SiteMinder Agent operating on a proxy server. This setting increases efficiency because the Web Agent operating on the destination server does not need to reauthorize users.

Default: No

ExpireForProxy

Prevents a client from caching content (pages and potentially headers or cookies). When the value of this parameter is set to yes , the Web Agent inserts one of the following HTTP headers into the HTTP response:

• Expires
• Cache-control

If content is not cached, subsequent requests continue to be forwarded.

When the ExpireForProxy parameter is set to yes, the Web Agent inserts the strings specified in the appropriate ProxyHeaderssuffix_name parameter into the HTTP response based upon what type of request the Agent performed.

For HTTP/1.1 requests, the Agent inserts the values of the following parameters as headers in the response:

• ProxyHeadersAutoAuth
• ProxyHeadersProtected
• ProxyHeadersUnprotected

For HTTP/1.0 requests, the Agent inserts the values of the following parameters as headers in the response:

• ProxyHeadersAutoAuth10
• ProxyHeadersProtected10

• ProxyHeadersUnprotected10

Default: No

Note: Although this parameter name contains the word 'proxy,' the settings of this parameter also affect the behavior of web browsers, or any other client that connects to a web server on which any SiteMinder Agents using this parameter setting operate.

To tell the proxy not to cache the pages, the Web Agent adds an Expires header for the page. This header is set to a date in the past, which prevents the page from being cached by a proxy, as dictated by the HTTP 1.0 specification. On 302 redirects, a cache-control: no-cache header is set instead. Although this prevents caching of content, this has the negative consequence of affecting the browsing experience for an Internet Explorer (IE) browser, as described by Microsoft Support.

With the use of cache-control: no-cache for 302 redirects, the ActiveX component that manages in-place document viewing in IE relies on the browser’s cache to locate the file. Because this header instructs the browser not to cache the file, the ActiveX component cannot locate the file and fails to display the request properly. Further, when you set the Web Agent’s ExpireForProxy setting to yes, the back-end server tells the proxy not to cache the resource.

To configure Agents that sit behind proxy servers

1. Set the ProxyTust parameter to yes.
2. Set the ExpireForProxy parameter to yes.
3. (Optional) Customize values the cache-control and ExpireForProxy (HTTP) headers.

   The Agents behind the proxy servers are configured.

More information:

Customize the Cache-Control and ExpireForProxy Header Settings