Install a Router
If you have an Internet connection that is always connected (cable, DSL, or wireless), you should install a router. This is a hardware device that directs traffic between a single Internet connection and one or more PCs on a local network. Many routers include a firewall, multi-port Ethernet switch, and wireless capability. The router offers protection against several kinds of Internet-based attacks and provides an inexpensive and simple but effective layer of protection even if you have just one computer.
To connect to the Internet or any other network, a computer must have an IP (Internet Protocol) address. A hacker who learns this IP address (or chooses it at random) can try to invade your computer. Certain Internet worms like Sasser and Blaster make rapid-fire attacks on all possible IP addresses, looking for vulnerable computers.
When you have a router in place, your computer gets all the benefits of connecting to the Internet, without the risk of getting hacked via its IP address. The router accomplishes this through Network Address Translation. Each computer on the network receives a local-only IP address from the router, usually something like 192.168.x.x. This type of address is completely invisible outside the local network. The router shuttles network requests and responses between the computers and the Internet, and any hacker or worm poking at the outward-facing IP address sees only the router.
A simple router shouldn't cost more than $40. But for additional protection at a somewhat higher price, you can get a router with a built-in firewall that uses Stateful Packet Inspection. This hardware firewall keeps a log of every outbound data packet and checks incoming packets against this log. Any incoming packet that doesn't match an outbound request is blocked. Certain activities, such as instant messaging, require acceptance of unsolicited inbound data packets, but most hardware firewalls include configuration options to allow these specific activities.
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