Chapter 21
In This Chapter
Considering the benefits of a network
Choosing between wired and wireless networks
Sharing an Internet connection
Gathering the stuff you need to network
Making the network connection
Using your network
Protecting your iMac with a firewall
In my book, network access ranks right up there with air conditioning and the microwave oven. As with other “I can’t imagine life without them” kinds of technologies, it’s hard to imagine sharing data from your iMac with others around you without a network. Sure, I guess you could still create a sneakernet (the old-fashioned term for running back and forth between computers with a floppy disk), but these days, Apple computers don’t even have floppy drives. (Even with a USB flash drive, a sneakernet is still a hassle.)
Whether you use your network to share an Internet connection, challenge your friends to a nice relaxing game of World War II battlefield action, or stream your MP3 collection to other computers that use iTunes, you’ll wonder how you ever got along without one. In this chapter, I fill you in on all the details you need to know to get your iMac hooked up to a new (or an existing) network.
If you have other family members with computers or if your iMac is in an office with other computers (including those rascally PCs), here’s just a sample of what you can do with a network connection:
If your iMac isn’t within shouting distance of an existing network or you don’t plan on buying any additional computers, stop right here — a lone iMac hanging out in your home with no other computers around probably won’t need a network.
After you decide that you indeed need a network for your home or office, you have another decision to make: Should you install a wired network (running cables between your computers) or a wireless network? Heck, should you throw caution completely to the wind and build a combination network with both wireless and wired hardware?
Your first instinct is probably to choose a wireless network for convenience. After all, this option allows you to eliminate running cables behind furniture (or in the ceiling of your office building). Ah, but I must show you the advantages to a wired network as well. Table 21-1 shows the lowdown to help you make up your mind.
Table 21-1 Network Decision Making
Factor |
Wireless Networks |
Wired Networks |
Speed |
Moderate |
Much faster |
Security |
Moderate |
Better |
Convenience |
Better |
Worse |
Compatibility |
Confusing standards |
Easier to understand |
Cables |
Few (or none) |
Required |
As I call it, here are the advantages of choosing a wired or a wireless network setup:
The performance of a wireless connection can be compromised by interference (from impeding structures, such as concrete walls; and from household appliances, such as some wireless phones and microwave ovens) and by distance.
Hackers can attack through your Internet connection. Always use a firewall. I subtly emphasize this point in the section “USE YOUR FIREWALL!” later in this chapter.
Accessing your network anywhere within your home or office — without expensive cables — is so easy. You can also easily connect a wireless printer. And when you’re using an AirPort Express mobile Base Station, even your home stereo can get connected to your MP3 collection on your iMac. Read more about Base Stations later on.
It’s time to see what’s necessary to share an Internet connection. In this section, I cover two methods of connecting your network to the Internet. (And before you open your wallet, keep in mind that you might be able to use your iMac to share your broadband connection across your network!)
Figure 21-1 illustrates how you can use your iMac to provide a shared Internet connection across a simple wireless network, using either
I recommend sharing a dialup modem Internet connection only if you have no other option. A dialup modem connection really can’t handle the data transfer speeds for more than one computer to access the Internet comfortably at one time. (In plain English, an external USB modem that you add to your iMac isn’t fast enough for both you and your significant other to surf the web at the same time.) Sharing a dialup connection just isn’t practical — and for many folks, even a single computer accessing the Internet over a dialup modem connection is far too slow.
In either configuration, your iMac uses the OS X Mavericks built-in Internet connection sharing feature to get the job done, but your iMac must remain turned on to allow Internet sharing. I show you how to do this in “Network Internet connections,” later in this chapter.
Figure 21-2 illustrates how a broadband connection works if you use a dedicated Internet sharing device (often called an Internet router) to connect to your cable or DSL modem. You have to buy this additional hardware, but your iMac doesn’t have to remain turned on just so that everyone can get on the Internet.
Internet routers usually include either wired or wireless network connections — and many include both.
Setting up an Internet router is usually a pretty simple matter, but the configuration depends on the device manufacturer and usually involves a number of different settings in System Preferences that vary according to the model of router you’re installing. Grab a diet cola, sit down with the router’s manual, and follow the installation instructions you’ll find there. (In some cases, you may need to set up your cable or DSL modem as a bridge between your ISP and your router, which should be covered in your modem and router manuals as well.)
Most normal folks — whom I define as those who have never met a network system administrator, and couldn’t care less — think that connecting to a network probably involves all sorts of arcane chants and a mystical symbol or two. In this section, I provide you with the shopping list that you need to set up a network, or connect to a network that’s already running.
Today’s iMacs come complete with built-in AirPort Extreme wireless hardware, so if you already have an AirPort Extreme or Express Base Station, you’re set to go. Otherwise, hold on tight while I lead you through the hardware requirements for wireless networking. (Kinda ironic, don’t you think?)
Connecting an Intel iMac to an existing wireless network requires no extra hardware because your hardware is already built in. (Whew. That was easy!)
If you decide that you want to build your own wireless network, you eschew cables, or you want to add wireless support to your existing wired network, you need a base station. The base station can act as a bridge between computers using wireless and your existing wired network. Such a wireless base station will have either
And, of course, a base station can simply act as a central switch for your wireless network (with no support for a wired network at all).
You can use either a cool Apple Base Station or a boring 802.11n or 802.11ac generic wireless base station; however, the Apple hardware requires less configuration and tweaking. (Sounds like a Mark’s Maxim!)
As listed in Table 21-2, your iMac can work with three different Apple Base Station models for wireless networking:
I recommend using AirPort Extreme if your network needs an enhanced antenna, which provides greater range. You can read about connectivity ranges in the upcoming Table 21-2. The Extreme is also a good pick if you need wired connectivity on your network.
I recommend using AirPort Express if you want to
Apple’s AirPort Time Capsule unit isn’t just a wireless remote hard drive for use with the Time Machine backup feature that’s built-in to Mavericks: It can also act as a full AirPort Extreme Base Station. In fact, the wireless specifications for an AirPort Time Capsule unit and an AirPort Extreme Base Station are almost identical.
The latest 802.11ac standard used by the AirPort Extreme and AirPort Time Capsule delivers a connection that’s several times faster than the old AirPort Base Station’s 802.11b/802.11g/802.11n standards. 802.11ac is also compatible with all the older standards — 802.11b/a/g/n — so I highly recommend that you stick with 802.11ac in the future. It plays well with others, and at warp speed, to boot!
Table 21-2 Apple Wireless Network Base Stations
Feature |
AirPort Extreme/AirPort Time Capsule |
AirPort Express |
Price |
$199/$299 |
$99 |
Users (maximum) |
50 |
50 |
802.11ac support |
Yes |
No |
802.11n support |
Yes |
Yes |
802.11g support |
Yes |
Yes |
802.11b support |
Yes |
Yes |
LAN Ethernet jack (high-speed Internet connection) |
Yes |
Yes |
WAN Ethernet jack (wired computer network) |
Yes |
No |
Stereo mini-jack |
No |
Yes |
USB printer port |
Yes |
Yes |
Installing an Apple Base Station is simple:
Only the AirPort Extreme and AirPort Time Capsule stations have a WAN port.
I cover the steps to share a printer in the upcoming section “Sharing a network printer.”
If any company other than Apple manufactured your wireless base station, the installation procedure is almost certainly the same. (Naturally, you should take a gander at the manufacturer’s installation guide just to make sure, but I have added many different brands of these devices in the past using essentially the same steps for each one.)
However, I should note that Apple wireless hardware uses a slightly different security encryption standard than most PC wireless hardware, which results in an extra hurdle when connecting to a non-Apple base station with your iMac. (More on this in the next section. For now, just remember that I recommend using Apple wireless hardware with your iMac whenever possible. It’s just a little easier!)
As far as I’m concerned, the only two types of base stations on the planet are Apple and non-Apple (which includes all 802.11ac, 802.11n, and 802.11g Base Stations and access points). In these two sections, I relate what you need to know to get onboard, using either type of hardware.
To join a wireless network that’s served by any flavor of Apple Base Station, follow these steps on each Mac with wireless support:
Note that Wi-Fi may appear labeled as Ethernet 2 instead. Whatever name it’s assigned on your iMac, however, you’ll still see the familiar “Wi-Fi fan” icon next to the port name.
The network name is the same as the network name you chose when you set up your AirPort Base Station.
By the way, security is always A Good Thing, and I strongly recommend that you enable the password encryption features of your Apple Base Station while installing it. (Luckily, the Apple Base Station setup application leads you through this very process.) In the words of an important Mark’s Maxim:
Some wireless networks might not appear in your Wi-Fi menu list. These are closed networks, which can be specified when you set up your AirPort Base Station. You can’t join a closed network unless you know the exact network name (which is far more secure than simply broadcasting the network name). To join a closed network, follow these steps:
To open the menu, click the AirPort status icon (which looks like a fan) on the Finder menu bar.
WPA2 is a far superior standard, so choose it over WEP whenever possible.
To disconnect from a Wi-Fi network, click the Wi-Fi menu and either
In other words, if you choose another available Wi-Fi network from the Wi-Fi menu, your iMac will automatically drop the previous connection. (You can be connected to only one wireless network at a time, which makes Good Sense.)
If you’re using your iMac to connect to a non-Apple base station, you might need to follow a specific procedure that takes care of the slightly different password functionality used by standard 802.11b/g/n/ac hardware.
Mavericks can take care of many potential wireless “language barriers” caused by security encryption (the two most common forms are WEP and WPA2), so whether you need to massage your password to connect to your non-Apple base station depends on the specific hardware and encryption system that it uses.
If you’re installing a wired network, your iMac already comes with most of what you need for joining your new cabled world. You just connect the hardware and configure the connection. Don’t forget that you also need cables and an inexpensive Ethernet switch. (If you’re using an Internet router or other hardware sharing device, it almost certainly has a built-in four- or eight-port switch.)
Your Ethernet 10/100/1000 port (which looks like a slightly oversized telephone/modem port) is located in the line of ports on the back of your iMac, ready to accept a standard Ethernet Cat5/Cat5E/Cat6 cable with RJ-45 connectors. If you’re connecting to an existing wired network, you need a standard Cat5/Cat5E/Cat6 Ethernet cable of the necessary length. I recommend a length of no more than 25 feet because cables longer than 25 feet are often subject to line interference (which can slow down or even cripple your connection). You also need a live Ethernet port from the network near your iMac. Plug the cable into your iMac and then plug the other end into the network port.
If you don’t know your switch from your NIC, don’t worry. Here, I provide you with a description of the hardware that you need for your wired network.
If you’re building your own wired network, you need
As I mention earlier in this chapter, most Internet routers (sometimes called Internet sharing devices) include a built-in switch. If you’ve already invested in an Internet router, before you go shopping for a switch, make doggone sure that the router doesn’t already come equipped with the ports you need!
After you assemble your cables and your router or switch, connect the Ethernet cables from each of your computers to the router or switch and then turn on the device. (Most need AC power to work.) Check the manual that comes with your device to make sure that the lights you’re seeing on the front indicate normal operation. (Colors vary by manufacturer, but green is usually A Good Color.)
Next, connect your cable or DSL modem’s Ethernet port to the WAN port on your switch with an Ethernet cable. If your modem isn’t already on, turn it on now and check for normal operation.
When your router or switch is powered on and operating normally, you’re ready to configure OS X for network operation. Just hop to the upcoming section “Connecting to the Network.” (How about that? Now you can add network technician to your rapidly growing computer résumé!)
After all the cables are connected and your central connection gizmo is plugged in and turned on, you’ve essentially created the hardware portion of your network. Congratulations! (Now you need a beard and suspenders.)
With the hardware in place, it’s time to configure Mavericks. In this section, I assume that you’re connecting to a network with an Internet router or switch that includes a DHCP server.
Follow these steps on each Mac running OS X that you want to connect to the network:
The Apply button is grayed out in the figure because my status (in this dialog) is Connected.
Enjoy the automatic goodness as OS X connects to the DHCP server to obtain an IP address, a subnet mask, a gateway router IP address, and a Domain Name System (DNS) address. (Without a DHCP server, you’d have to add all this stuff manually. Ugh.)
A few seconds after clicking the Apply button, you should see the information come up. You might also notice that the DNS Server field is empty, but fear not: OS X is really using DNS Server information provided by the DHCP server.
You’re on!
All right! The hardware is powered up, the cables (if any) are installed and connected, and you configured Mavericks. You’re ready to start (or join) the party. In this section, I show you how to share data and devices with others on your network.
It works … by golly, it works! Okay, now what do you do with your all-new shining chrome network connection? Ah, my friend, let me be the first to congratulate you, and the first to show you around! In this section, I cover the most popular network perks. (And the good news is that these perks work with both wired and wireless connections.)
If your DSL or cable modem plugs directly into your iMac (rather than a dedicated Internet sharing device or Internet router), you might ponder just how the other computers on your network can share that spiffy high-speed broadband connection. If you’re running a wireless network, it comes to the rescue!
Follow these steps to share your connection wirelessly:
Mavericks displays a warning dialog stating that connection sharing could affect other computers on your network. If you intend to share the Internet connection provided on an existing network at your home or office that you didn’t set up, contact your network administrator first! (Best to avoid sowing chaos and disorder.)
Don’t forget that you won’t need to configure Internet sharing if your DSL or cable modem connects to a dedicated sharing device or router. That snazzy equipment automatically connects your entire network to the Internet.
You can swap all sorts of interesting files with other Macintosh computers on your network. When you turn on File Sharing, Mavericks lets all Macs on the network connect to your iMac and share the files in your Public folder. (Note: Sharing across a network is different from sharing a single computer betwixt several people. I cover that environment in Chapter 20.)
Follow these steps to start sharing files and folders with others across your network:
Other Mac users can connect to your computer by clicking Go in the Finder menu and choosing the Network menu item. The Network window appears, and your iMac is among the choices. If the other Macs are running Mavericks, your iMac’s shared files and folders appear in a Finder window, and they’re listed under the Shared heading in the Sidebar.
Windows XP users should be able to connect to your Mac from their My Network Places window, and Vista/Windows 7 users can use the Network window. (Windows 8 users should head to the Network panel instead.) Those lucky Windows folks also get to print to any shared printers you’ve set up. (The following section covers shared printers.)
Boy, howdy, do I love describing easy procedures, and sharing a printer on a Mac network ranks high on the list! You can share a printer that’s connected to your iMac (or your AirPort Extreme, AirPort Time Capsule, or AirPort Express Base Station) by following these very simple steps:
A printer that you share automatically appears in the Print dialog on other Macs connected to your network.
Yep. That’s the only heading in this entire book that’s all uppercase. It’s that important.
The following Mark’s Maxim, good reader, isn’t a request, a strong recommendation, or even a regular Maxim; consider it an absolute commandment (right up there with Get an antivirus application now).
When you connect a network to the Internet, you open a door to the outside world. As a consultant to several businesses and organizations in my hometown, I can tell you that the outside world is chock-full of malicious individuals who would dearly love to inflict damage on your data or take control of your iMac for their own purposes. Call ’em hackers, call ’em delinquents, or call ’em something I can’t repeat, but don’t let them in!
Mavericks comes to the rescue again with the built-in firewall within OS X. When you use this, you essentially build a virtual brick wall between you and the hackers out there (both on the Internet and even within your local network). Follow these steps:
This is an important feature that prevents hackers from trolling for your iMac on the Internet — or, in normal-speak, searching for an unprotected computer — so it’s much harder for them to attack you.
Mavericks even keeps track of the Internet traffic that you do want to reach your iMac, such as web page requests and file sharing. When you activate one of the network features that I demonstrate in the preceding section, Mavericks automatically opens a tiny “hole” (called a port by network types) in your firewall to allow just that type of communication to your iMac. For example, if you decide to turn on File Sharing (as I demonstrate earlier), Mavericks automatically allows incoming file access.
You can also add ports for applications that aren’t on the firewall’s Allow list. These applications include third-party instant messaging (IM) clients, multiplayer game servers, and the like. Depending on the type of connection, Mavericks will often automatically display a dialog prompting you for confirmation before allowing certain traffic, so most folks won’t need to do anything manually.
However, you can add a program manually to your list of allowed (or blocked) Firewall ports. Follow these steps:
Mavericks displays a standard File browsing sheet.
The application appears in the Firewall list. By default, it’s set to Allow Incoming Connections.