18.2. Network Central—and Multihoming In this chapter, you'll be spending a lot of time in the Network pane of System System Preferences; click Network.) This list Preferences (Figure 18-1).(Choose summarizes the ways your Mac can connect to the Internet or an office network
18.2. Network Central—and Multihoming
In this chapter, you'll be spending a lot of time in the Network pane of System
Preferences (Figure 18-1).(Choose System Preferences; click Network.) This list
summarizes the ways your Mac can connect to the Internet or an office network—
Ethernet, AirPort wireless, Bluetooth, FireWire, cellular modem card, VPN (Chapter 22),
and so on—and how each connection is doing.
Figure 18-1. The network connections listed here are tagged with color-coded dots.
A green dot means turned on and connected to a network; yellow means working,
but not connected at the moment; red means you haven't yet set up a connection
There's quite a bit going on here in this radically redesigned control panel; for example, it
completely replaces the old Internet Connect program. Now you set up all your network
connections here, and you can connect and disconnect to all your networks here.
What you may not realize is that the order of the network connections listed here is
important. That's the sequence the Mac uses as it tries to get online. If one of your
programs needs Internet access, and the first method isn't hooked up, the Mac switches to
the next available connection automatically.
In fact, Mac OS X can maintain multiple simultaneous network connections—Ethernet,
AirPort, dial-up, even FireWire—a feature known as multihoming.
This feature is especially relevant for laptops. When you open your Web browser, your
laptop might first check to see if it's at the office, plugged into a cable modem via an
Ethernet cable, which is the fastest, most secure type of connection. If there's no Ethernet,
it looks for an AirPort network. Finally, if it draws a blank there, the laptop reluctantly
dials the modem. It may not be the fastest Internet connection, but it's all you've got at the
Here's how to go about setting up the connection attempt sequence you want:
1. Open System Preferences. Click the Network icon.
The Network Status screen (Figure 18-1) brings home the point of multihoming:
You can have more than one network connection operating at once.
2. From the pop-up menu, choose Set Service Order.
Now you see the display shown in Figure 18-2. It lists all the different ways your
Mac knows how to get online, or onto an office network.
Figure 18-2. The key to multihoming is sliding the network connection
methods' names up or down. Note that you can choose a different connection
sequence for each location. (Locations are described later in this chapter.)
3. Drag the items up and down in the list into priority order.
If you have a wired broadband connection, for example, you might want to drag
Built-in Ethernet to the top of the list, since that's almost always the fastest way to
4. Click OK.
You return to the Network pane of System Preferences, where the master list of
connections magically re-sorts itself to match your efforts.
Your Mac will now be able to switch connections even in real time, during a single
Internet session. If lightning takes out your Ethernet hub in the middle of your Web
surfing, your Mac will seamlessly switch to your AirPort network, for example, to keep
your session alive.
All right then: Your paperwork is complete. The following pages guide you through the
process of setting up these various connections.