You are the network administrator for ExamSheet. 
There are 200 Windows 2000 Professional computers on your network. All computers on the network access the Internet by using a Microsoft Proxy Server computer named Proxy1. The IP address of Proxy1 is 192.168.99.5. You discover that Proxy1 is experiencing performance degradation due to the large number of requests to authenticate with the proxy server. You want to minimize the number of authentication requests to the proxy server. What LAN configuration should you modify on each computer?   
To answer, select the appropriate configuration setting or settings that should be modified in the Local Area Network Settings dialog box in the Work Area.

You are the network administrator for ExamSheet.net. You administer ExamSheet’s Windows 2000 network. You upgrade 10 computers in the Accounting department from Windows NT Workstation 4.0 to Windows 2000 Professional. All of the upgraded computers are configured to have the default security settings. For security purposes you want to ensure that these computers can only communicate with other Windows 2000 computers. 
What should you do？（）