Troubleshooting your OS X Mac's Internet Access

This page outline some useful steps that you can take to diagnose problems with your Mac's Internet access. You've got your broadband service installed, you set up the router (wired or wireless), you set up your Mac, you launch Safari, and you type in http://www.apple.com, and to your disappointment you get a message such as "The server could not be found" or "Unable to open that page after trying for 60 seconds."

Check The Configuration Again

The next up will be to try to isolate the problem to a specific component of your network. To connect to the Internet, your Mac must be working properly, it must be able to communicate with the router, the router must be able to communicate with the Internet, and the Mac must be able to communicate through the router to the Internet. The following steps will help you determine which of those links in the chain between your Mac and the website of your choice isn't working.

Check Connection to Router

Router Brand	Web Admin URL
Apple Airport	Use Airport Admin Utility
LinkSys	http://192.168.1.1
DLink	http://192.168.0.1
Belkin	http://192.168.2.1
NetGear	http://192.168.0.1
SMC	http://192.168.2.50
MacSense	http://192.168.1.1

If even that much of the connection does not work:

• Open System Preferences, go to the Network pane, set the Show: pulldown menu to whichever interface you are using, "Built-in Ethernet" or "Airport", and pick the TCP/IP tab. What is the IP address? It should be something beginning 192.168.

  A value starting 169.--.--.-- is definitely self-assigned, meaning it didn't come from the router's DHCP server. That's bad.

  

  If it isn't, then you have failed to obtain and IP address from the Dlink router DHCP server. Make sure the Configure: pulldown menu is set to "Using DHCP". If using OS X 10.3, click the "Renew Lease" button.

• If you are trying to use wireless with a non-Apple router, make sure the Router's preamble is set to long. Assuming the wired connection works fine, use the wired connection to access the Router's administration page. The location of this setting varies by the brand of router, but it is usually hidden away on some advanced wireless settings page.

  LinkSys	Advanced / Wireless
  Netgear	Advanced / Wireless
  DLink	Advanced / Performance
  Belkin	Advanced / Performance

  If you can't access the Router's Admin a page from the Mac, but you do have a valid IP address:

• Open System Preferences, go to the Network pane, set the Show: pulldown menu to Network Port Configuration. Make sure the "Airport" line is enabled, and drag it to the top of the list.
  

• Open the Terminal application (in /Applications/Utilities folder) and type the command: "ping -c3 17.254.3.183" and press return (that's Apple's IP address, if you're interested.) the command should report (after a little chatter): "3 packets transmitted, 3 packets received, 0% packet loss".
  

  If it does, then your problem is probably the DNS server.

  If that ping command waits a few minutes and then reports "100% packet loss", test on:

• Open the Terminal application and type the command "route -vn get 17.254.3.183" and press return. That should report a bunch of information, including reports of the interface and gateway.
  

  If it says that, then it indicates that the Mac is configured to access the Internet via one of these interfaces:

  en0	Built-in Ethernet
  en1	Airport
  pp0	Internal Modem (PPP)

  If the interface it displays doesn't match what you expected it to use, open System Preferences, Network pane, and set the Show: pulldown to "Network Port Configurations", as shown earlier on this page, and make sure the interface you want to use is enabled and on the top of the list.

  The value reported for the router should match the IP address used in the URL used to contact the routers administration utility, in the case of this Linksys router, 192.168.1.1. Using the Apple Airport Base Station, you should show a value of 10.0.1.1.

If none of that suggests the solution, then report back with what you discovered, and see if there are other suggestions can be made.

If something above seems missing, confusing or down-right wrong, you can eMail me as car1son at my .Mac account. (Please be very specific at what point things went wrong and how they went wrong.)

Good luck!