Scenario 1: One of your employees sends you an e-mail reporting that he just received a message that appears to have come from his own e-mail address. The message urged him to install a new virus protection program to guard against the Klez virus. Before installing the program, the employee wanted to check to make sure it would not conflict with other virus protection programs already on his computer. What should you tell him?

Scenario 2: You are hired as a security consultant for a twenty-person mortgage company whose members routinely receive e-mails and other files containing loan and salary information about their clients. When you check existing security systems, you find that e-mail messages containing viruses, ping and echo requests, and packets in which the source IP and destination IP are the same, are routinely being allowed through the stateless packet filter, which is a router at the perimeter of the network. One of your initial instructions was to make the network as secure as possible. You were also told to boost security to protect our clients personal information. Describe the changes you would make to improve the packet filtering setup.

Scenario 3: In the same office scenario as #2, you have improved the packet filtering setup, but you are still receiving communications from hackers that have virus attachments (which, luckily, the existing antivirus software has so far been able to detect and block). In addition, one of the computers on your network has been targeted for port scans by someone who has apparently been able to obtain the IP address. What network security approach would you used that goes beyond packet filtering and hides internal IP addresses? When asking to purchase this item, what argument could you make to company managers to indicate that it is better than packet filtering?