Mac OS X Location tips
Location settings in Mac OS X, configured from the "Network pane" of the System Preferences application, are a powerful way to set up your computer if you routinely connect to different kinds of networks.
For the most part, the default settings will work. The default settings in the "Automatic" location are designed to work with most networks, and most networks will "just work." Why? Because the "Automatic" location attempts to get all of its settings from the network the computer connects with.
For example, with the "Automatic" location's defaults, you can take your PowerBook from the campus Ethernet network to the campus wireless network, and then pack up your computer and take it home to a Time Warner Road Runner cable modem connection. At home, you could connect to your cable modem either through a broadband router device, or through a wireless base station (that may be part of your broadband router). All of the settings in the "Automatic" location are the same, and there is no reason to change them just because you've carried your computer home.
Locations collect three basic kinds of settings, so there are three reasons to create a new location setting for different networks:
- Enable or disable ports
- Change the order of ports
- Different settings for an interface.
Enable or disable ports
You may want to turn off a physical network interface that you do not want to use in certain situations. By default, all of the available interfaces in your computer are turned on by the system software. If you have disabled a port, you can also re-enable it later.
For example, if you never dial-in to the Internet, you can turn off the "Internal Modem" port.
We generally recommend that you leave all ports enabled.
Change the order of ports
You want to change the order that physical network interfaces are tried for active connections.
We generally recommend that you change the order of your ports, even in the default "Automatic" location, to reflect the relative speed of each connection. The connections will be tested for valid Internet connections in top to bottom order, so it makes sense to put your fastest connections at the top of the port list. For most Macs, this order would change to:
- Built-in Ethernet
- AirPort
- Internal Modem
Different settings
If you need different settings for an interface at different times, then you can create two different locations to handle the changes.
One example of a change you may need to make is if a particular network requires you to enter an IP address for an Ethernet connection. This is rare, however; the campus network and most local ISPs use DHCP to configure their wired networks.
Another example is when you need to connect to the RIT DialIP service. Setting up this service does require changing options for your "Internet Modem" port. However, if you only dial-in to RIT -- and do not use your modem to connect with other dial-in services -- then you can safely change these settings in the "Automatic" location.
The settings you might need to change correspond to the fields under any of the tabs when you choose to "Show" a particular physical interface like "Built-in Ethernet" or "AirPort." The tabs under those interfaces include:
- TCP/IP
- PPP
- PPPoE
- AppleTalk
- Proxy
- AirPort
