Type the new password; type the password again to confirm. 6. Optionally, enter a hint.

Part III ✦ Working with Networked Computers Using Mac network commands Each operating system for the Mac has distinctive networking commands and features. You should use these commands or applications only if you’re comfortable with the computer and you understand the consequences of your actions. Earlier versions of the Mac operating system, such as System 8 or 9, have a Network Assistant that you can use to help manage the network. Do not try to use the Network Assistant with Mac OS X, however; you could damage the operating system. Following are just a few of the incidents that could happen: The computer doesn’t start, the computer starts up with a flash- ing question mark, or a kernel panic happens during or after startup. Using Linux network commands Most distributions of Linux include network commands you can install. Common commands enable you to configure the network interface, display configuration, map drives, share print- ers, and so on. IFCONFIG is a command you can use to display the current configuration. It describes the IP address, subnet mask, and a broadcast address of the subnet. You can also use the PING com- mand with Linux boxes. NSTAT and NETSTAT are two commands that result in network statis- tics relating to the computer on which it is typed. Protecting the Network from Viruses One of the first procedures any computer should perform when it boots is to check for viruses. Viruses are computer programs that disrupt or destroy your files, file system, soft- ware, hardware, your work, or even your network. A virus might only display a message, or it could erase or reformat your hard disk. A virus can attack one computer and then travel the network to other computers and your server. New viruses are found daily, each with its own brand of destruction and aggravation. Your computer can catch a virus from a contaminated floppy disk, a file on the network, a file downloaded from the Internet, or a file attached to an e-mail message; a virus can even ride on the back of a worm through your Internet connection. After it’s infected, your computer crashes and burns; worse yet, your infected computer could take down the entire network. Your network is only as strong as its weakest computer when it comes to fighting viruses and worms. Because viruses can quickly spread over the network, it’s important that all computers on the network are protected. Many computers come with an antivirus program installed — Symantec or Norton AntiVirus or McAfee VirusScan, depending on the computer manufacturer. Many other antivirus applications are available. You should use a virus program daily, and you should keep the program’s list of viruses called definitions and cures updated. Discuss with your employees the danger of bringing disks from home and downloading files from the Internet — especially e-mail. Also, require all users to keep an antivirus program run- ning on their computers all the time so that it catches viruses as they appear on the com- puter. One virus spread to a network can cost hundreds of thousands of dollars in hardware damage and data corruption. Small Business Tip Note