140 CHAPTER 9: MONITORING W EB ACCESSAccess Logging Access Logging allows you to track which client machines have accessedwhich Web sites through the Webcache. You can configure theWebcache to log all Web accesses. Access Logging and the Squid accesslog format are enabled by default but if you want to change the logformat do the following:1 Log in to the Web interface.2 Click Caching on the Toolbar.3 Select Setup Access Log in the Navigation Tree.4 Select one of the five access log formats: Squid (default) WebTrends Extended (WELF) Netscape Common Netscape Extended Netscape Extended 2You can view the last 256 lines of the Access Log using the View AccessLog command; for further information, see “Viewing the Access Log” onpage 142.To disable Access Logging, simply un-check the Enable Web AccessLogging box from the Setup Access Log screen and click OK.The Squid format is the most widely supported by log analysis tools. Ifyou are using WebTrends Firewall Suite to analyze the Webcache’s accesslogs, you should always use the WebTrends Extended Log Format (WELF)for additional Web access information.Filter Logging The Filter Log stores information about clients who try to access blockedsites, and the reason why the request has or would have been blocked.See “Filter Logging” on page 159.Storing the LogFilesYou can specify an FTP server to which you want to periodically save thelog files. If this option is enabled, both the access and filter logs areoffloaded to the FTP server whenever any log file reaches 250 MB in size,or every 24 hours, whichever comes first. You can see a complete historyof every Web request made through the Webcache and every Webdua1611-5aaa04.book Page 140 Friday, November 29, 2002 8:56 PM
