Hello there, I'm currently in the process of configuring Tomcat. The network configuration is a bit above avarage: The Tomcat 5.0.14 server serves a site at The http requests come in to the router. The router is running Apache 1.3.22, and uses ProxyPass and ProxyPassReverse to forward the request to the Tomcat server. So we access the site using a normal domainname (sub.domain.com), and the router routes it to This all goes well. But... We use form based authentication using j_security_check to authenticate our users. This goes wrong. The moment the user logs in correctly, we get a "HTTP Status 400 - Invalid direct reference to form login page" reply. The description field says: "The request sent by the client was syntactically incorrect (Invalid direct reference to form login page)." The funny thing is: when the user logs in INcorrectly, everything goes ok (the user gets the right error page). The most funny thing is that when we access the site directly (using, all goes well. Still, I have the feeling the problem is with Tomcat, not the Apache proxy... But what's wrong? How can I see what data j_security_check is getting, so I can debug the problem? Does anyone have a solution whatsoever? The Tomcat server is always behind the router in a dmz. I can not / will not install Tomcat on the router for security reasons. If anyone can give me directions where to look for an awnser, I'd be gratefull. At the moment I'm just guessing, and I don't have any more ideas... (So I'm kinda desperate) -- Jurrie