| 3.6 |  | Task 4: Define Inspection Rules |
| 3.6.4 |  | Inspection rules for URL filtering |

| A Cisco IOS firewall, running 12.2(15)T, can interact with Websense or N2H2 URL filtering software, allowing an administrator to prevent users from accessing specified websites on the basis of a defined policy. The Cisco IOS firewall works with the filtering server to know whether a particular URL should be allowed or denied (blocked) , . Websense and N2H2 are third-party filtering software packages that can filter HTTP requests on the basis of the following policies: destination hostname, destination IP address, keywords, and username. The software maintains a URL database of millions of sites organized into more categories and subcategories.

To verify that the Firewall filtering feature is working, perform any of the following optional steps as shown in Figure . Other commands can be used to clear and debug filtering . A sample configuration is shown in Figure .

All US education institutions and public libraries are mandated to provide web filtering in order to receive federal funding. Many businesses utilize the service to improve employee productivity and minimize liability. URL filtering can also implemented using a Cisco PIX Security Appliance or Content Engine.

| Web Links http://www.cisco.com/en/US/products/ sw/iosswrel/ps5012/products_feature_ guide09186a0080146556.html N2H2
http://www.n2h2.com

Websense
http://www.websense.com