Installation guide

Trend Micro™ InterScan™ Web Security Virtual Appliance 6.5 Installation Guide
2-20
Web page requests follow this sequence:
1. The Web client sends a request to the HTTP proxy server.
2. The proxy server forwards the request to IWSVA.
3. IWSVA validates the request using URL Filtering/URL Access Control:
• If the URL is invalid (blocked), the HTTP service sends the HTTP client an
appropriate notice, completing the transaction.
• If the URL is valid, the HTTP service forwards the request to the Web server
on the Internet.
4. The contacted Web server returns a response (ideally a Web page) to IWSVA.
5. IWSVA performs its processing on the returned data (virus, spyware, ActiveX
scanning), then forwards the appropriate response/data to the proxy server.
6. The Proxy server caches the data (if cacheable), then delivers the response/data to
the HTTP client.
F IGURE 2-9. HTTP Proxy in Dependent Mode (Proxy Behind)
T ABLE 2-5. HTTP Proxy in Dependent Mode (Proxy Behind)
A DVANTAGES L IMITATIONS
No configuration changes required
on the clients.
Configuration changes or pattern
updates on IWSVA do not affect cached
objects.