Chapter 3

Going Wireless

In This Chapter

Finding out how wireless networking works

Discovering wireless security

Connecting to other Macs without a wireless access point

Connecting to and disconnecting from Wi-Fi networks

Nowadays, wireless connectivity is king. For example, mobile phones have gone from being a toy of the technological elite to a permanent fixture on the hip of homo sapiens. The shorts I’m wearing right now have a special pocket just for a cell phone to ride in; when I’m without my phone, the pocket usually carries a 5th Avenue candy bar. (Perhaps that was too personal … sorry.)

Because people have become accustomed to being able to keep in touch wherever they are, they also want to be able to have access to their network, at least in their house or workplace, without the hassle of cables (which are magnets for pets that enjoy a good chew toy). This desire for convenience and the advances in wireless technology have combined to bring you the wireless network — as well as wireless coffee shops, wireless access providers, and even wireless gaming centers.

Now you can be connected to your home local area network (LAN) and your shared Internet connection (which I cover in Chapter 4 of this minibook) from your balcony, lounge chair in the yard, or even your bedroom. (And yes, you can go wireless in your office too.) In this chapter, I talk about how wireless networks work, and I give you lots of information to help you get the right pieces to free yourself — securely, mind you — from the world of the wired.

Speaking the Wireless Lingo

Wireless networks aren’t all that different from their wired siblings. In this chapter, I discuss some of the features and limitations of wireless networking, but you must first be familiar with a foundation of information.

Because of the technology involved in wireless networks and how things are changing rapidly in this area, you’ll find yourself swimming in a sea of acronyms and other techno-babble. Although you don’t need to know every little detail to be able to set up your own wireless network, you should know some of these terms so you can avoid getting stung by hackers or stuck with equipment that’s on the verge of obsolescence.

Here’s a quick list of terms that you’ll see on your road to becoming a wireless network guru:

• WLAN: Wireless LAN. If you’ve read earlier chapters in this minibook, you know that a LAN is just a bunch of connected computers and other devices.
• IEEE: Institute of Electrical and Electronics Engineers. This organization approves standards that allow computers, network equipment, and just about anything else electronic to play nicely together. Sometimes IEEE helps create these standards before approving them, and sometimes it just approves standards that others have produced.
• 802.11: This term refers to the part of the IEEE standards that deals with wireless networking.

  Although wireless is usually generically referred to as wireless networks (Apple uses the term Wi-Fi), it’s all really a wireless form of Ethernet.

• WAP: Wireless access point. This device allows wireless network devices to connect to a wired Ethernet network.
• SSID: Service Set Identifier. This text tells your computer the name of the wireless network that you want to use.
• WEP: Wired Equivalency Privacy. This encryption can be used by wireless networks to keep your wireless network more secure from snoopers and hackers.
• WPA: Wi-Fi Protected Access. This security protocol is more robust and harder to crack than WEP. The latest version, WPA2, is a common security feature on today’s wireless hardware.
• Wi-Fi Direct: A relatively new wireless standard that allows direct connectivity between devices without the need for a wireless base station or WAP.
• Ad Hoc mode: In this type of wireless network, each wireless device talks directly with all other wireless devices.

  Apple calls Ad Hoc mode a computer-to-computer network.

• Infrastructure mode: All wireless devices talk to a WAP, and the WAP then talks to other wireless devices and the wired network.

As I cover the different parts of wireless networking and how to set it up, you’ll find yourself using these terms over and over. Before you know it, you’ll be spouting these wireless-related acronyms like a pro. (Really. I’m not kidding.)

Figuring Out the Different Flavors of Wireless Ethernet

One of the first things that you might notice when you start looking into wireless networking is the existence of different wireless standards. You should at least be aware that these standards exist: That way, you can be sure to get wireless network components that will work together because some of the wireless standards are not compatible. (Feel free to photocopy this list and stick it on your fridge door.)

Basic Wi-Fi: 802.11b

In the beginning, IEEE 802.11b had another name that you’ll likely see on product advertisements, literature, or boxes in stores: Wi-Fi, which stands for Wireless Fidelity. (Kinda like that cutting-edge Hi-Fi stereo from the ’60s and ’70s, where Hi-Fi stands for High Fidelity.) Now manufacturers (including Apple) use the term Wi-Fi to refer to all flavors of wireless Ethernet.

Don’t be confused when you see “Wi-Fi” in the Network pane in System Preferences. To Apple, any wireless Ethernet — including the much faster 802.11n and 802.11ac that are standard equipment on Macs today — is Wi-Fi hardware.

802.11b was the first version of wireless Ethernet. This version of wireless runs at speeds up to 11 million bits per second, or 11 Mbps — roughly the equivalent of the original 10 Mbps wired Ethernet standard. The reason I say that it runs at speeds up to 11 Mbps is because the actual speed at which the data is transferred depends on things such as signal strength and quality. When the conditions are such that your signal strength or quality is decreased — an inconvenient concrete wall or a circuit breaker box between you and your AirPort Base Station — you might find that your wireless connection changes down to 5.5 Mbps, 2 Mbps, or even as slow as 1 Mbps.

802.11b has been largely supplanted in current wireless networking, and almost all the equipment you can buy today is either 802.11n or 802.11ac (both of which I cover in a moment). However, if you’re working with older computers and existing 802.11b hardware, any new networking equipment you buy today should be backward-compatible with 802.11b.

Apple’s original AirPort network cards and standard-issue AirPort Base Station used 802.11b. It’s time for Mac owners to swell with pride yet again: Apple was the first computer company to ship 802.11b hardware. (Back then, in 1999, it was the original AirPort Base Station.) Now, of course, Apple has raised the bar with AirPort Extreme, which I discuss later in this chapter, and the AirPort Express mobile Base Station.

In theory, 802.11b network cards have the capability to communicate with other wireless Ethernet devices and WAPs that are up to 1,000 feet away. Having said that, realize that 1,000 feet is a generous estimate (and that’s outdoors on a clear day with no wind blowing) — you see what I’m getting at. In reality, when you set up your wireless network, things such as walls — especially concrete walls, as in basements — and areas with lots of electrical wiring decrease the distance that you can cover. If you use a WAP, plan on no more than 150 feet between wireless computers and the WAP. However, your mileage might vary.

Your Wi-Fi network bandwidth is shared between all computers using it. Collisions can also occur if more than one computer tries to communicate at the same time. If you have lots of people on your wireless network, the network becomes noticeably slower because of increased collisions. Remember that the total bandwidth is shared among the computers on the wireless network. This applies not only to 802.11b but also to the 802.11a (which I cover in the nearby sidebar) and the 802.11g standards.

One last thing about 802.11b networking: It uses the 2.4 GHz frequency range. (It uses 11 different channels, but they’re all around the 2.4 GHz range.) So if you’re using a 2.4 GHz cordless phone or even a microwave, either device can interfere with or even shut down your wireless network. Keep this in mind when you buy your next phone or wonder why your file transfers stop when you’re communing with Orville Redenbacher in the microwave.

Let’s get Extreme: 802.11g

Apple’s release of the first generation of AirPort Extreme provided both the speed of 802.11a and the compatibility with 802.11b devices. That’s because it used the 802.11g standard, which operates at speeds up to 54 Mbps (as did 802.11a) but also operates at the same frequency ranges and plays nicely with existing 802.11b equipment. (Notice that we’re heading in the right direction again when it comes to naming conventions. Go figure.)

Apple was again the first company to offer 802.11g hardware as standard equipment. Feel free to enjoy the Superiority Dance yet again.

Naturally, there’s a downside: 802.11g returned to that pesky 2.4 GHz range, so your cordless phone and microwave can also wreak the same havoc that they did with your original 802.11b AirPort equipment.

The current standard: 802.11n

The 802.11n standard is currently the most popular wireless flavor. Most third-party manufacturers now offer only 802.11n wireless equipment. 802.11n is supported by the entire range of current Apple products, including the AirPort Extreme Base Station, the AirPort Express, the AirPort Extreme hardware in most of the Macintosh computer line, the iPod touch, iPad and iPhone, and the spiffy Apple TV.

802.11n offers throughput in excess of 100 Mbps — roughly equivalent to a 100 Mbps wired Ethernet connection — but don’t bet your house that you’ll get that kind of speed, though. (As with the other members of the 802.11 family, that’s likely to be a theoretical maximum speed.)

Although no longer the fastest horse on the track, the 802.11n standard offers compatibility with virtually all current wireless networking hardware. Only 802.11ac offers a better connection … speaking of which …

Raising the bar to 802.11ac

I would be remiss if I didn’t mention the latest wireless standard from IEEE: 802.11ac. (I know, I know, these engineers seem to have lost their way in Alphabet Land. Just concentrate on the good things they do.) Anyway, all of Apple’s latest Macs, the AirPort Time Capsule, and the AirPort Extreme offer 802.11ac wireless compatibility, which is — get this — almost three times as fast as 802.11n! Of course, before you invest your retirement income in 802.11ac hardware, don’t forget my SWD (Standard Wireless Disclaimer): In most real-world situations, you won’t get anywhere near that maximum speed or range.

The guy with the turquoise teeth

I should also mention Bluetooth — a strange name for a wireless standard, I admit, but it works like a charm. Bluetooth devices use 2.4 GHz as well, but they’re designed only for very short distances — only about 30 feet. Bluetooth is the future for linking mobile devices (such as tablets and smartphones) and external peripherals (such as wireless keyboards and mice) to your Mac. In fact, Bluetooth connectivity is now available for all sorts of awesome devices: wireless headphones, external speakers, car audio systems, and printers, just to name a few. Bluetooth also plays an important role in Yosemite’s Handoff and AirDrop features.

Bluetooth is built in to all current Macs, which can turn your iMac or Mac Pro into a completely cordless machine — except for the power cord, of course. Yosemite provides built-in support for Bluetooth through the Bluetooth pane in System Preferences.

Keeping Your Wireless Network Secure

Are you worried about the security of your AirPort wireless network? You should be, bunkie. Imagine someone in the next apartment or house — or standing right in your street — intercepting and monitoring your data from your wireless network.

But before you decide to toss the idea of a wireless network, keep this in mind: Even though it is technically possible that someone might camp out on your doorstep to gain access to your wireless network, this possibility isn’t very probable for most home networks. Even if someone tries to gain access to your wireless network and perhaps even sniff your network — a techno-nerd term meaning to record all the data flying around a network — there isn’t much someone can do with that information.

You might say, “But I use my credit card on the Internet to buy stuff.” Sure, this is a valid concern; however, if you purchase things on the Internet with your credit card, you should already be using a secure connection provided by the website for your personal information so the data you’re sending across your wireless network is encrypted and relatively safe from thieves. (You can find more on this where I discuss Safari in detail in Book V, Chapter 5.)

“I have shared my files on my computer. Can the Bad Guys access those shared files?” Another good question, but if you read Chapter 2 of this minibook, you know that you have to create an account for those whom you want to access your files. Unless the would-be hacker is very good at guessing usernames and passwords, your files are pretty safe, too.

This is not to say that you bear absolutely no risk of being hacked. If a legitimate user on your wireless network connects to your computer and starts transferring a file, a would-be hacker could potentially record all the traffic and then reconstruct the file that was sent from the data that was recorded. In other words, a hacker could grab that user’s username and password. That’s where the following encryption standards come in handy!

WPA and WPA2

Wi-Fi Protected Access (WPA) is A Good Thing (even if it makes for a silly-sounding acronym). It’s currently the standard encryption protocol offered for home wireless networking — WPA2 standard is the latest version — and is even better at defending your wireless network. As you might expect, all of Apple’s current AirPort wireless hardware supports WPA2 security, as does most of the wireless hardware you’ll find on the shelf at your local Hardware Heaven electronics store. (It’s still a good idea to check the specifications on the box, though, to make sure that WPA2 is supported.)

WPA2 works well as a deterrent to keep the wrong people out of your stuff. Although WPA2 isn’t going to ward off the spies at the National Security Agency, it’s good enough to protect home and small-business networks.

WEP

Wired Equivalency Privacy (WEP) is an old friend of mine (albeit another ridiculous acronym for another wireless security system). WEP was one of the first widely supported wireless encryption schemes, but in today’s world, WEP is now outdated and pretty easy for a hacker to outwit. I strongly recommend that your network use WPA2 whenever possible.

Apple’s implementation of WEP comes in two varieties: 40 bit and 128 bit. The more bits used in the encryption, the more secure (and the better) it is.

To use WEP, you need to select a WEP key, which is really just a code word. And speaking of keys:

• The longer the key, the better.
• When making a key, use something undecipherable, such as ab8sher7234ksief87 (something with random letters and numbers as opposed to something that’s easily guessed, like mykey).

If you’re using an Ad Hoc wireless network, all the computers need to have their wireless network card configured with the same WEP key to communicate. If you’re using a wireless access point to connect to the rest of the network, your computers need to use the same key that you’ve configured on your wireless access point.

It’s very important to remember that WEP has been broken, meaning that someone has figured out how to undo the encryption that WEP provides. For businesses, especially those with sensitive data, WEP isn’t a good security solution.

The LEAP security standard

Lightweight Extensible Authentication Protocol (LEAP) is an encryption protocol developed by Cisco Systems for superior security in the business world. To use LEAP, you must have a server that’s set up to enable users to log in to gain permission to the wireless network. After you initially log in (authenticate) to your network, LEAP changes encryption keys on the fly at a time interval that you determine. You could set it so that every 15 minutes your encryption key is changed: Even if someone is in that hypothetical tent on your front lawn, he could never record enough packets to figure out your key because it changes so often.

Setting up a server so that you can use LEAP isn’t something for the novice to attempt. I would encourage you to read up on LEAP only if you’re very serious about airtight security on your WLAN. The Cisco website (www.cisco.com) is a good place to read about LEAP.

All current AirPort Extreme wireless network hardware and the Apple AirPort Time Capsule are compatible with the Cisco LEAP standard for higher security.

Setting Up Your Wireless Network

On to the good stuff. This section describes how to set up an Ad Hoc or infrastructure-based WLAN (wireless LAN).

In case you have any issues using AirPort or need more information about anything related to AirPort, check this page at the Apple website: www.apple.com/support/airport.

Setting up an Ad Hoc wireless network

Using an Ad Hoc network — also called a computer-to-computer network — is a fairly easy thing to accomplish in OS X. Plus, you’re not limited to just Macs: With an Ad Hoc network, you can also swap niceties with PCs, tablets, and phones that have 802.11b/g/n/ac network hardware installed. This Ad Hoc network is great for setting up an impromptu network in a classroom, exchanging recipes and pictures at a family reunion in a park, or blowing your friend up while gaming across the aisle of a Greyhound bus at 70 mph.

Yosemite does not create a secure Ad Hoc network, so never transfer sensitive or personal information over a computer-to-computer network.

To set up an Ad Hoc network, you first have to create the computer-to-computer network on one of your Macs. This process takes advantage of the AirPort Software Base Station that’s built into Yosemite.

To create a computer-to-computer network, follow these steps:

1. Click the Wi-Fi status icon on the menu bar.

   If you haven’t set Yosemite to display your Wi-Fi status in the Finder menu bar, follow these steps:

   1. Open the Network pane in System Preferences, and choose the Wi-Fi entry in the list at the left of the pane.
   2. Enable the Show Wi-Fi Status in Menu Bar check box.
   3. Close the System Preferences window to save your changes.
2. Click Create Network to display the dialog that you see in Figure 3-1.

   

3. Enter a name for your network.
4. (Optional) Select a channel for the connection.

   In general, channels 1, 6, and 11 are the only ones that don’t overlap other channels — and are therefore the best choices to use. If you’re close to other wireless access points (including AirPort Time Capsule devices, AirPort Base Stations, or other Ad Hoc networks), try to find a channel that’s not being used; otherwise, performance can be degraded. (If you have only one access point, the channel you select doesn’t matter — just allow Yosemite to select a channel, which is typically channel 11.)

5. Click Create.

Creating a computer-to-computer network gives the illusion of having an AirPort Base Station. So for people to join your network, they would follow the same steps as those they would use to join any other AirPort Wi-Fi network, as I cover in the next section.

Setting up wireless networks

After one computer is running a computer-to-computer network or you’ve set up and configured an AirPort Extreme Base Station, AirPort Express, or AirPort Time Capsule, you’re ready to invite other computers with wireless hardware to the party.

Joining an existing Wi-Fi network

After you have a network set up on one of your wireless-enabled computers, you just need to have the other wireless-enabled computers join that network. You can use the same process, as I describe here, to join any wireless network (think your local coffee shop or your hotel room on your next trip):

1. Click the Wi-Fi status icon on the Finder menu bar.

   A list of existing network connections appears in the AirPort menu.

2. Select an existing network connection that you’d like to join.

   If you want to join a network whose name doesn’t appear in the list — a closed network — follow these steps:

   1. Select Join Other Network from the Wi-Fi icon menu.
   2. Enter the name of the network you want to join.
   3. If the network uses security encryption, click the Security pop-up menu, choose the proper encryption format — the administrator of the network should be able to tell you the correct format — and type the password. If you plan on using the network in the future, make sure the Remember This Network check box is enabled.
   4. Click Join.

   A closed network is another added measure of security — one that’s good enough for most people because it’s very unlikely that a hacker is going to try to break into a hidden network.

Disconnecting from a Wi-Fi network

To disconnect from a Wi-Fi network, you can turn off your Wi-Fi hardware, which I cover in the next section. (Simplicity, they say, is an art.) Another way is to connect to another Wi-Fi network, but this option is useful only if you want to connect to another network.

Turning your Wi-Fi hardware on or off

Being able to turn your Wi-Fi hardware on and off has its uses:

• Freedom: You might want to use your Mac, usually your MacBook, in a place where your wireless hardware shouldn’t be used because of interference with other equipment.
• Conservation: Turning off your Wi-Fi hardware conserves your MacBook’s battery life.

To turn your Wi-Fi equipment on or off using the Wi-Fi status icon on the Finder menu bar, give it a click and choose Turn Wi-Fi On/Off from the resulting menu.