The symptoms of this issue include:
- Safari, iChat, and other Internet-dependent applications in Mac OS X may display the message "You are not connected to the Internet."
- Mail may put all of your email accounts into an "Offline" status.
- iOS devices cannot use other Internet features, such as the App Store.
- Apple TV may be able to use Home Sharing with computers on your local network, but not any features that require Internet access, such as movie trailers or rentals.
- In Mac OS X, an AirPort menu bar icon with an exclamation point may appear, and the AirPort menu may state "Alert: No Internet Connection…".
Use this article if:
- Your Mac, iOS device, or Apple TV is connected to a network that should provide access to the Internet, and which has a functioning DHCP server (such as an AirPort base station in default configuration).
- Your Mac, iOS device, or Apple TV is assigned an IP address of 169.254.xxx.xxx by your DHCP server, or you have manually assigned it an IP address of 169.256.xxx.xxx.
- Your Internet-facing router is being assigned an IP address of 169.254.xxx.xxx by your ISP.
- Make sure your Your Mac, iOS device, or Apple TV is properly connected to your home Wi-Fi network (or via Ethernet if your Mac or Apple TV uses an Ethernet cable).
- Make sure your router (such as an AirPort base station in default configuration) is working properly and is assigning IP addresses to your devices via DHCP. See this article for details.
- If your ISP is assigning your Internet facing router, Mac, or iOS device an IP address of 169.254.xxx.xxx, contact the ISP support staff and ask for a proper IP address to access the Internet.
- If the DHCP server has been configured to issue an IP address of 169.254.xxx.xxx, contact the administrator of the DHCP server and ask that they issue a proper IP address to access the Internet, such as what is issued by an AirPort base station in default configuration (10.0.1.25 or similar). A DHCP server should not be issuing an IP address of 169.254.xxx.xxx.
- If you have manually configured your Mac or device with an IP address of 169.254.xxx.xxx, reconfigure your device to use a proper IP address to access the Internet.
The 169.254.xxx.xxx IP address space is reserved for self-assigning or link-local IP addresses. They are used when your device is not connected to any network at all or a network that has no DHCP server, so that devices can assign their own IP address. When these devices use Bonjour, they can create their own DNS name resolution on the network. This is useful when you are connected to a network that is completely isolated; you will be able to network to other devices and even see their share names and Bonjour advertised services.
RFC 3927 covers the details of this IP address space. Section 1.6 covers the "Alternate Use Prohibition" of this IP space.
Note: In certain situations, a computer or wireless device may create an ad-hoc Wi-Fi network for setup or file sharing purposes. These Wi-Fi networks do not typically provide Internet connectivity. Common network names for some ad-hoc networks may include "Free Public WiFi", "HP Setup", or "default".