Self assigned IP address

Sorry jcdill - another update with late breaking news. Your solution DOES work, if I am within about 20 feet of the router. As soon as I move out of that range, I get the self-assigned IP again.

So - perhaps this is not a Lion / Mountain Lion issue at all? Hard to imagine the OS would affect wi-fi range... or at least it's hard for me to imagine.

I will check the MBP discussions, but does anyone know if a reduction in range is indicative of a failing airport card?

Just tried this but it did not work.

After trying pretty much all the suggestions here, and still getting nowhwere.

As other devices could connect without a problem, I was starting to get just a tad peeved.

I then stumbled onto the fact that the security profile on my router WPA2 was using TKIP, changing to AES the wireless now works flawlessly.

Hopefully this helps

Spec

YET ANOTHER SOLUTION THAT WORKS:

I have had this happen on multiple computers. In one case one of the posted solutions here worked. However, in a recent situation I required a different solution for a router that had multiple Macs all failing to wirelessly connect in the same way. These same computers worked a year ago on the same router! Something in the MAC OS has changed.

THE SOLUTION IN THIS CASE: Turn off MAC filtering on the router (if you don't know what this is you almost certainly don't have it set up and this is not a solution for you, because it would NOT be a default router configuration). Even though the MAC addresses for the computers were programmed into the Router MAC filter, something about that filter is a problem. My guess is that it is a problem in the MAC OS in its interaction with the router filtering, since a windows machine worked fine on the same network and nothing has changed with the router. I have NOT tried turning the filtering back on to see if it works once I met with success, because in this case I didn't care and I must move on.

Hopefully Apple fixes their software soon, because this problem is crippling and seems to manifest itself in a half dozen different ways (i've seen two so far.)

Yes indeed, a very irritating issue!

After reading the posts here, i have tried to combine several possible solutions.

Now Ethernet -> Wi-Fi Internet Sharing works and also with Firewall on. I have done:

1. put Internet Sharing and Firewall off

2. done the instruction from: Desigurl03

1. Click on Macintosh HD

2. Click on the file labeled "Library"

3. Click on the file labeled "Preferences"

4. Click on the file labeled "SystemConfiguration"

5. Then move these three documents to the trash (don't delete them just in case but your computer should remake these documents on its own

1. com.apple.airport.preferences.plist

2. com.apple.network.identification.plist

3. NeworkInterfaces.plist

6. Then restart your computer and you should be good to go and if you are you can go ahead and delete those documents in your trash (that is what I did) because one of those documents was corrupted.

3. redo all your settings in Wi-Fi Internet Sharing

4. put Internet Sharing on

Test the Internet Sharing with other device.

When it works:

5. put Internet Sharing off (don't know this is needed)

6. put Internet Sharing on again

7. put Firewall on again

Hope it stay working.

This worked for me!!! THANKS. Hey guys, if you are using DROPBOX defenitely check this option out. THANKS man I created my apple ID just to say thank you ily.

Hi everyone,

I think I have tried every solution published on all the Internet forums worldwide... None have worked for me. But... I have made a clean re-install of Mountain Lion... Twice ! The first one left the problem unchanged... So I have tried a second time... And now, it is working all right. I don't understand what has happened and why it is working now, but it works just fine ! So the big mistery of networking connections is still on !

Regards to everyone.

I've tried EVERYTHING and nothing has worked. I switched from PC to Mac because of the reliability but now I can't fix anything! I could rebuild a pc from the ground up!

After having a hard drive crash that apple knew was faulty, and now this I'm ******. What a waste of everybody's god **** time.

If are you near an Apple Store make a genius bar appointment and take your Mac in for technical assistance.

Make sure your wifi security is configured correctly.

If are using a lot of third party software, check to see if any of it has added kernel extensions, especially anything using the network in a non-standard way, like a game server, for example. Sometimes a third-party kernel extension totally messes up your ability to connect by wifi. A lot of programmers just port things games from Windows without regard for the OS X API, then try to work around the problems they create by adding kernel extensions. Not good, but true.

After all of this checks out and gets fixed:

Go to System Preferences in the Apple menu.

Click on Network. (It may say Network Settings on some system systems.)

Click the Turn Wifi Off button near the top of the Network panel.

Unlock the lock in the lower left corner if necessary. This requires admin ID and password.

Click Advanced button

Select your wifi network and

Click the minus ➖ sign to delete it

Click OK

Click Apply

Open the Keychain Access application in Applications > Utilities folder.

Find your network name in the list.

Delete the login password for your network.

Then go back to Network settings and turn wifi on.

Click Advanced button.

Click plus ➕ sign.

Click Choose a Network.

Select your network and enter your password

Click Okay

Click Apply

This should work. Sometimes the settings get hosed, but not very often. I have had this happen once in 10 years with Mac OS X.

@Annoyedatappleagain

Probably not the forum to vent your anger.

If you really don't like the Apple OS then vote with your feet.

I use Macs and PCs on a daily basis and have about 7 computers on my desk. I'm very confident with Windows, Mac, Linux, UNIX, Solaris etc. and I choose Macs for my own personal computer, albeit, I run Windows and Linux in VMs on my MacBook too.

Hard disks are mechanical devices that *will* fail and Apple don't manufacturer them so you can't blame them for that. If you can rebuild a PC from the ground up a mere hard drive crash shouldn't cause you any problems anyway!?

If you're having issues with your machine picking up an IP address - try rebooting and logging in as the guest user. Can you get on wifi and get a DHCP address through that account?

Or in your normal account install a Virtual Machine program and install another OS - bridge the VM's NIC - can your windows box get an IP?

Liam

hey guys...I found the problem...it helped me very much 🙂 just try to change the wireless mode from 11bgn mixed to 11bg mixed...do this from router settings,wireless settings 🙂 I guess this will help you

Improper wifi settings in the router are frequently the problem. When I worked for Apple Retail we always tried to own the problem and solve it, not blaming the router. But the router was often the problem. For example, if you are having the problem at home, but not at Panera Beard or Starbucks or the Apple Store, then the problem is your wifi router.

Hi This solucion works for me. Its pretty simple as create a new location.

Take a look to this tutorial video:

http://www.youtube.com/watch?v=dMxD9Bh7brk

Another possible solution if other things dont work.

Just went through many steps listed to figure this out and depending on folks situation it can also be caused by the router. I found that in my situation for a business that the DHCP on the wireless router was set to only except addresses from (example) 192.168.10.1 - 192.168.10.10. With that configuration only 10 people could get on that router unless it was changed to say 192.168.10.1 - 192.168.10.100 (now it has room for 100 people). .Once the business hit the initial 10 that was set originally by ISP (provider) nobody else was getting on.

All I can say is "WOW, that was FUN, NOT". Hope this will help somebody else in need if the other steps posted earlier didnt help.

TFCTECH

I tired everything and still it doesn't work. So I turned off the modem for 1 mintute and than turned it on. My internet is back!!! So easy but I took me 4 hours to figured it out and made me so worried and upset!!!