182 CHAPTER 11: C ONTROLLING HOW W EB SITES ARE CACHEDCache Control Cache Control allows you to control the caching behavior of theWebcache for specific Web sites. Cache control works in any deploymentmode and has two functions: Cache Control can be used to reduce traffic across your WAN networkand improve response time to your clients by pinning content for aperiod of time between an hour and a week. The Web sites that arepinned when requested by a client will be served from the Webcachewithout checking if the content has changed. Cache Control can also be used to prevent the caching of Web sitesthat do not work correctly if cached. For example, if you believe a Website is returning expired content, you may wish to ensure it is notcached by including it in the Cache Control list.Unlike Cache Bypass, requests made to Web sites marked Never Cacheare still subject to Content Filtering, as described in Chapter 10, and arealso recorded in the Access Log.Setting Up CacheControlTo set up Cache Control using the Web interface:1 Log in to the Web interface.2 Click Caching on the Toolbar.3 Select Cache Control > Setup Cache Control in the Navigation Tree.4 Check Enable Cache Control.You will be warned that entries in the Cache Control list will not takeeffect until cached objects are cleared with the Clear Cache command.5 Click OK to save your changes.You must clear cached objects before the current Cache Control list cantake effect. If you are going to further configure Cache Control, forexample by adding or removing domains from the list, you may want towait until you have completed those tasks before clearing the cache.To clear the cache see “Clearing the Cache” on page 186.Creating a CacheControl ListYou can create a list of the domain names, IP addresses or IP addressranges of Web sites that you want to prevent from being cached or havepinned in the following ways:dua1611-5aaa04.book Page 182 Friday, November 29, 2002 8:56 PM
