19.4. AirPort Networks

19.3. Broadband Connections

If you have a cable modem, DSL, or office network, you're one of the lucky ones. You have a high-speed, broadband connection to the Internet that's always available, always on. You never have to wait to dial, disconnect, or download. You're connected to the Net via your Mac's Ethernet jack or AirPort connection, leaving its built-in modem benched.

19.3.1. Automatic Configuration

The real beauty of most broadband connections these days is that they require no setup whatsoever . Take a new Mac out of the box, plug in the Ethernet cable to your cable modem, and you can begin surfing the Web instantly.

That's because most cable modems and DSL boxes automatically feed all of the necessary configuration settings to the Mac (including techie specs like IP address and DNS Server addresses), courtesy of a glorious feature called DHCP . This acronym means dynamic host configuration protocol , which is techese for: "We'll fill in your Network pane of System Preferences automatically."

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Note: The bad news is that DHCP doesn't necessarily give you a single, unchanging IP address, which can make it more difficult to use the remote control features of Mac OS X, like dialing in from the road. There is a workaround, however; see Section 22.1.

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POWER USERS' CLINIC
PPPoE and DSL

If you have DSL service, you may be directed to click the PPPoE tab (in the Network pane of System Preferences). It stands for PPP over Ethernet, meaning that although your DSL "modem" is connected to your Ethernet port, you still have to make and break your Internet connections manually, as though you had a dial-up modem.

Fill in the PPPoE tab as directed by your ISP (usually just your account name and password). From here on in, you start and end your Internet connections exactly as though you had a dial-up modem.

You may discover that turning on PPPoE disables AppleTalk. If you need AppleTalk (for connecting to older Macs on the network, for example), here's a tip: On the Network pane of System Preferences, choose Show Network Configurations. Duplicate and rename your Ethernet setup. Set up the new configuration with AppleTalk on, using a manually assigned IP address (like 192.168.1.10).

Now your Mac can talk on two "networks" at once on the same Ethernet port ”your DSL company and your older Macs on the network.

19.3.2. Manual Configuration

If, for some reason, you're not able to surf the Web or check email the first time you try, it's conceivable that your broadband modem doesn't offer DHCP. In that case, you may have to fiddle with the Network pane of System Preferences, preferably with a customer-support rep from your broadband provider on the phone.

On the Network pane, from the Show pop-up menu, choose either AirPort or Built-in Ethernet, depending on how your Mac is connected to the broadband modem. Now you see something like Figure 19-3.

Figure 19-3. Don't be alarmed by the morass of numbers and periods ”it's all in good fun. (If you find TCP/IP fun, that is.)
In this illustration, you see the setup for a cable-modem account with a static IP address, which means you have to type in all of these numbers yourself, as guided by the cable company. The alternative is a DHCP server account, which fills most of it in automatically.

The next step is to make a selection from the Configure pop-up menu. Only your service provider can tell you exactly which settings to use, but you'll probably be asked to choose Manually. That is, your cable or phone company will tell you precisely which IP address (Internet address) to type in here. The bad news is that you'll also have to fill in all the other boxes here ”Subnet Mask, Router, and so on ”with cryptic numbers separated by periods.

On the other hand, look at the bright side: You've just been given a static IP address , an Internet address that is all your own and that won't change. Because your Mac has this one reliable address, several cool Mac OS X features are available to you.

For example, it's easier to access your files from anywhere in the world, as described in Chapter 22.

That's all the setup ”click Apply Now. If your settings are correct, you're online, now and forever. You never have to worry about connecting or disconnecting.