birt barcode generator Figure 9-15. Setting a time server in Font

Generator QR Code ISO/IEC18004 in Font Figure 9-15. Setting a time server

From a security standpoint, the Apple AirPort Express closely resembles the Apple AirPort. The key difference is that the AirPort Express has a port dedicated for playing audio. iTunes has a field that can be used to log into an AirPort Express and play audio to the device.

AppleTV with far more features to eventually replace the AirPort Express. However, it is widely used in the world of Mac networking, and therefore it s worth discussing.

To reliably secure the AirPort Express features for playing audio, log into the AirPort Express, and click the Music Icon in the toolbar. This opens a screen that allows you to disable AirTunes, which you should do if you are not using this feature. If you are using AirTunes, then create a speaker password using the AirTunes option in AirPort Setup (shown in Figure 9-16), which will then be required by anyone using the AirPort Express to listen to music.

As mentioned, David Maynor clearly demonstrated that Apple client computers are not immune to wireless attacks. When using a public wireless network, it is often best to make sure you are using a secure means of authenticating and transmitting data. For example, when traveling, we always use a VPN to connect to our office network and access resources. This extra layer of authentication keeps the data away from prying eyes that may be watching these public networks.

Note When your AirPort connection is not in use, make sure to turn off the AirPort. Any time you are not

using the wireless, try to keep it turned off. To disable it, just click the AirPort icon at the top of the screen, and click Turn AirPort Off (see Figure 9-17).

A computer-to-computer network is similar to other wireless networks except that it is a network without a central base station. In previous versions of OS X, computer-to-computer networks were known as ad hoc networks. The security features available on computer-to-computer networks are limited. When creating a computer-to-computer network, WEP is disabled by default, and WPA is not available. To create a secured computer-to-computer network, click the wireless icon at the top of your screen (see Figure 9-18), and choose the Create Network option. From here, click the Enable Encryption (Using WEP) option, and choose the level of encryption you want to use (128-bit is typically the best). Once you have selected your encryption level, enter a password, and click the OK button to establish the wireless network.

Where a wireless network is placed on the network can greatly impact the security level of the network. Many wireless networks, for ease of use, will want to have NAT disabled, allowing AppleTalk and Bonjour connections into devices on the wired network. For larger networks where security is paramount, network administrators should strongly consider putting an Apple AirPort in a demilitarized zone (DMZ). A DMZ sits outside the corporate firewall and can have a completely different set of rules for how network traffic works as compared to the internal corporate network. The default configuration of an Apple AirPort has NAT enabled. This removes the ability of the wireless clients to communicate over broadcast networks with upstream networks. However, clients can still communicate by IP address with upstream networks. Therefore, this is not actually a DMZ but instead a subnetwork of your main network. Communications are still possible and less controllable. The preferred location of AirPorts and wireless access points is in a demilitarized zone. By placing the wireless access point in a network above rather than below in terms of the network architecture, your corporate NAT wireless clients will not be able to communicate directly with your corporate network. From here, users can establish a VPN tunnel into the network, and traffic will be most effectively encrypted. This topology requirement is often employed in larger companies, and in the future you ll probably see more and more wireless protocols developed around it.