IN THIS CHAPTER
Grasping the fundamentals of common networking hardware
Learning how NAT and DHCP work
Giving outside computers access to part of your network
Directing outside services to particular computers on your network
Channeling Internet access through a local proxy server
Using 802.1X for network authentication
The infrastructure of the Internet largely comprises a physical network of fiber optic and copper cables spread across the globe. With a few exceptions (such as long-range Wi-Fi and satellite access), most homes and businesses with Internet access connect to the outside world via physical cables of some kind. For reasons of performance and security, most businesses rely primarily on wired networks, typically using Ethernet cabling to connect computers to each other and to the Internet by way of one or more switches, hubs, routers, or gateways. But even people who use Wi-Fi to access the Internet usually have a partially wired network — for example, the cabling going from an AirPort base station to a DSL, cable, fiber, or satellite modem and then to the Internet.
The information sent over the Internet is exactly the same regardless of whether it's carried by radio waves or Ethernet cables. But in terms of security, wired and wireless networks face somewhat different types of threats. The biggest risk in using wireless networks is direct snooping by someone in your proximity. But any portion of your wired network directly exposed ...