Firewall Features 23The Firewall will protect your network against the following Denial ofService attacks: Ping of Death Smurf Attack SYN Flood LAND Attack IP Spoofing TeardropTo find more information on DoS and other attacks refer to Chapter 13,“Types of Attack and Firewall Defences”Advanced users can extend the security functions of the Firewall byadding network access rules and user privileges. See “Examples ofNetwork Access Rules” on page 200 and “User Privileges” on page 205for more information.Web URL Filtering You can use the Firewall to monitor and restrict LAN users from accessinginappropriate information on the Internet. You can block access to thisinformation or record attempts to access it in a log. See “Filter Settings”on page 162 for more information.You can create a list of all forbidden URLs to which you want to restrictaccess. Alternatively, you can restrict access to the Internet to certaintrusted URLs. See “Setting up Trusted and Forbidden Domains” onpage 165 for more information.Web site technologies such as cookies and Java and ActiveX applets giveenhancements to web pages, but hackers may use the technologies tosteal or damage data. The Firewall can block these potentially damagingapplications from being downloaded from the Internet, or allow themonly from trusted sites. See “Filter Settings” on page 162 for moreinformation.You can also use the optional SuperStack 3 Web Site Filter to extendthese filtering capabilities of your Firewall. It provides a list of Web sitecategories that might be considered inappropriate for business use. TheWeb Site Filter updates the Firewall with the latest URLs matching theselected categories. You can block access to these sites or log them. TheFirewall is supplied with a one-month free subscription. You can thenDUA1611-0AAA02.book Page 23 Thursday, August 2, 2001 4:01 PM
