By Lawrence C. Miller

Part of Home Networking Do-It-Yourself For Dummies Cheat Sheet

Warning! Your computer has encountered a fatal error. Please contact your system administrator. Guess what? On your home network, you are the system administrator! It’s important that you know some basic terminology in case you have to do some extensive troubleshooting with your ISP or need to buy some new hardware.

Domain Name System (DNS): DNS translates Internet addresses (such as to IP addresses (such as so routers can find Web sites (among other things) on the Internet. Typically, your ISP will provide you a primary and secondary DNS server address. You configure DNS in your computer’s network settings (or set it up on your DHCP server to automatically configure your computers and other network devices with DNS information).

Dynamic Host Configuration Protocol (DHCP): DHCP automatically assigns IP addresses to the devices on your network. You pre-configure a range of allowable IP addresses on a DHCP server (such as a router or computer) that runs on your network.

Ethernet: Ethernet is a networking standard. Although there are other types of networks, Ethernet is by far the most common and is almost exclusively the only standard used in home networking. You will encounter this term frequently when shopping for various network hardware, such as routers, modems, and cables.

Internet Protocol (IP) Address: Every device (for example, computers, printers, routers, and gaming consoles) on a network must have a unique address. An IP address consists of four sets of numbers from 0 to 255, separated by a decimal (for example,

Internet Service Provider (ISP): An ISP provides Internet service to individuals and businesses. Typical options for high-speed Internet access include DSL and cable.

Malware: Short for malicious software, malware is software code that is designed to damage files or entire computer systems, steal data, disrupt network, and do generally bad things to computers, networks, and people. Malware consists of viruses, worms, Trojans, spyware, adware, backdoors, rootkits, and bots.

Phishing: Phishing (pronounced like fishing) e-mails are a type of spam used by identity thieves to trick an individual into revealing private data, such as banking account information or passwords. Many phishing attempts appear to come from a legitimate sender such as your bank, and may even include authentic logos and links to the actual bank’s Web site (as well as other links that may install other malware or take you to a malicious Web site).

Rootkit: A rootkit (or backdoor) is a program that allows an attacker to covertly gain access to your computer in order to steal data, do damage, or control your computer.

Service Set Identifier (SSID): An SSID uniquely identifies your wireless network and is broadcast by your wireless access point.

Spyware: Spyware quietly collects information about users on your computer or network. Spyware can be used to monitor a computer user’s activities or even log keystrokes.

Trojan: A Trojan (or Trojan horse) is malware that masquerades as legitimate software. Once a Trojan has been installed on a computer, it can do extensive damage to a computer or network, including deleting files, stealing data, and installing other viruses.

Virtual Private Network (VPN): A VPN allows two networks to be connected securely over the Internet as if they were one network. For example, you might use a VPN to connect your home network to your corporate network (if your company permits you to connect to the office from home).

Wi-Fi Protected Access (WPA and WPA2): WPA and WPA2 are wireless security standards for protecting your wireless network and the data on your wireless network.

Worm: A worm is similar to a virus, but does not require a host program or file and can replicate and infect computers with human action. Worms typically take advantage of a known vulnerability or bug in a computer program or operating system.