24 CHAPTER 1: INTRODUCTIONpurchase a twelve month Web Site Filter (3C16111) subscription. Boththe trial and the twelve month subscription are valid for an unlimitednumber of users.High Availability Given the mission critical nature of many Internet connections eachcomponent involved in your connection must be highly reliable. The HighAvailability function of your Firewall adds to the already reliable platformeliminating downtime due to hardware failure.To use the High Availability function, connect another SuperStack 3Firewall to the first as a high availability pair and configure the backupFirewall to monitor the primary Firewall. In the event of failure of theprimary Firewall, the backup Firewall will take over its functions. See“Configuring High Availability” on page 141 for details.Logs and Alerts The Firewall maintains a log of all events that could be seen as securityconcerns. It can also track key events such as the top 25 most accessedWeb sites, or the top 25 users of Internet bandwidth. You can also set upthe Firewall to send an alert message through e-mail when a high-priorityconcern, such as a hacker attack, is detected. See “Log/Alert Settings” onpage 177 for more information.For detailed logging 3Com recommends that you us a syslog server or asyslog reporting tool. A free syslog server is available from 3Com. Todownload it point your web browser to:http://www.3com.com/ssfirewalland follow the link to the Syslog Server.User Remote Access(from the Internet)Users can access intranet resources on the private LAN by successfullylogging into the Firewall from the Internet. Logging in requires a validuser name and password, which are transmitted to the Firewall by theremote user, using a Web browser, through an MD5-based encryptedauthentication mechanism. Once logged in, remote users are able toaccess all IP resources on the LANAutomatic IP AddressSharing andConfigurationThe Firewall provides sharing of a single public IP address throughNetwork Address Translation (NAT). It also provides simplified IP addressadministration using the Dynamic Host Configuration Protocol (DHCP).DUA1611-0AAA02.book Page 24 Thursday, August 2, 2001 4:01 PM
