Web Filter Block Page Flow (Invisible Mode)


This article applies to:

  • Web Filter
  • Web Filter and Reporter

Question: 

How does the Web Filter serves a block page to a client in Invisible Mode?

Reply:

  1. The Client sends a request to a web site, which is also received by the Web Filter.
  2. The Web Filter sends a TCP reset to both the Client and the web site, so that the Client doesn't keep requesting the web site, and the web site doesn't keep trying to serve to the Client.
  3. The Web Filter then sends an HTTP 302 Redirect to the Client.
  4. The Client issues an HTTP GET https://<ip_address>:81/block.cgi to the Web Filter.
  5. The Web Filter serves the Client the block page.

     

    Last Modified 3/10/2017.
    https://support.trustwave.com/kb/KnowledgebaseArticle20554.aspx