Apple MacBook Air (11-inch, Mid 2011) - Manual (Page 48)

48 Chapter 3 Problem, Meet Solution
If you have two or more computers sharing an Internet connection, be sure that your
wireless network is set up properly. You need to know if your ISP provides only one IP
address or if it provides multiple IP addresses, one for each computer.
If only one IP address is provided, then you must have a router capable of sharing
the connection, also known as network address translation (NAT) or “IP masquerading.”
For setup information, check the documentation provided with your router or
ask the person who set up your network. You can use an AirPort base station to
share one IP address among multiple computers. For information about using
an AirPort base station, check Help Center or visit the Apple AirPort website at
www.apple.com/support/airport.
If you cannot resolve the issue using these steps, contact your ISP or network
administrator.
Problems with Wi-Fi Communication
If you have trouble using Wi-Fi (wireless communication):
 Make sure the computer or network you’re trying to connect to is running and has
a wireless access point.
 Make sure you’ve properly configured the software according to the instructions that
came with your base station or access point.
 Make sure you’re within range of the other computer or the network’s access
point. Nearby electronic devices or metal structures can interfere with wireless
communication and reduce this range. Repositioning or rotating the computer might
improve reception.