iMac won't pickup IP Address

[nsheikh80]

I have been having some Apple woes recently and am wondering if you guys can help.

Lately, my wifi on my iMac (intel Core Duo running 10.4.8) has been a bit flaky. I've had to turn it on and off to get it to pick an IP address from my router. A bit tedious but thats ok. Sometimes I even had to do it a coupole of times. However, last night I found that my Mac would just not pick up an IP address from my router no matter what I did. I have tried restarts, resetting the PRAM and turning the wifi card on and off numerous amounts of times. I have even tried resetting my router and starting from scratch. My brothers Windows laptops connected fine to the router before and after the router was reset. It is a Linksys router.

Now here is where it gets pretty spooky. When I boot up in Windows on my iMac via Boot Camp (so windows is running natively not virtually) the wifi card works fine. Its picks up an IP address and works flawlessly every time! This means that its probably down to an OS issue. Does anyone have any ideas?

My internet connection is hared via the router to all PC's macs in the house. The Mac is telling me that Airport is connected but is not getting an IP address. I have changed the SSID name 3 times to see if that had anything to do with it but none of the different names worked. I did a hard reset on the router which gave it factory default settings - completely open WiFi with no security. This didn't work either. At every stage I tried connecting via Windows in Boot Camp on the Mac and also via IBM Thinkpads and it worked flawlessly each time.

I would appreciate any help no matter how small.

 

[Queso]

Remove all references to the Wi-Fi network's SSID from your Mac's Keychain. See if the iMac can then pick up the IP address. If it can, the problem was a corrupted encryption key in the Keychain itself. Re-enter your WEP/WPA settings first on the router then on the Mac.

If it can't get the IP address, check the MAC address of the Airport card by opening a Terminal and typing "ifconfig en1". Note down the hex numbers on the line that begins "ether", then restart the Mac into Windows and check it gives the same number when you type "ipconfig /all" into a Command Prompt. If it's different, there's something screwy going on with your network configuration in OSX.

 

[thewhitehart]

Everyone has had brilliant suggestions to this problem, but the truth is, apple refuses to acknowledge that 10.4.8 has borked airport on intel macs. I'm not being sarcastic - there are so many people who have been helpful with suggestions, ranging from simply reordering preferences, resetting keychain entries, to more complex methods like resetting PRAM and trashing library folders. I've tried all of them, and posted specifically in this forum about a thousand times about this very same problem. None of the solutions offer a permanent fix, however. I've noticed that all of us having this problem have something in common: intel macs and 10.4.8. The core 2 duo owners have the extra headache of a very slow connection, but all of us have had problems with airport dropping out, self assigned IPs, and our networks disappearing all together, even though windows PCs can connect to the same routers just fine.

Telling us that airport works ironically perfectly under windows in Boot Camp puts the proof in the pudding. 10.4.8 on intel has destroyed airport, and Apple will not acknowledge it. I've had no problems whatsoever under 10.4.7 and earlier, and running an ibook on 10.4.8 simultaneously have had no problems. Besides the chip set, my hard drive on the intel imac, and the drive on the ibook are virtually the same.

 

[nsheikh80]

Remove all references to the Wi-Fi network's SSID from your Mac's Keychain. See if the iMac can then pick up the IP address. If it can, the problem was a corrupted encryption key in the Keychain itself. Re-enter your WEP/WPA settings first on the router then on the Mac.

If it can't get the IP address, check the MAC address of the Airport card by opening a Terminal and typing "ifconfig en1". Note down the hex numbers on the line that begins "ether", then restart the Mac into Windows and check it gives the same number when you type "ipconfig /all" into a Command Prompt. If it's different, there's something screwy going on with your network configuration in OSX.

Thanks for the suggestions.

I deleted all entries in the keychain and when I tried to connect it actually asked me for the WEP, yay! Or so I thought. Once I enetered in the WEP key it failed to get an IP address.

I checked the MAC address of the Airport card under OS X and Windows and they're both the same.

Thanks for your help but the saga continues.

 

[nsheikh80]

Everyone has had brilliant suggestions to this problem, but the truth is, apple refuses to acknowledge that 10.4.8 has borked airport on intel macs. I'm not being sarcastic - there are so many people who have been helpful with suggestions, ranging from simply reordering preferences, resetting keychain entries, to more complex methods like resetting PRAM and trashing library folders. I've tried all of them, and posted specifically in this forum about a thousand times about this very same problem. None of the solutions offer a permanent fix, however. I've noticed that all of us having this problem have something in common: intel macs and 10.4.8. The core 2 duo owners have the extra headache of a very slow connection, but all of us have had problems with airport dropping out, self assigned IPs, and our networks disappearing all together, even though windows PCs can connect to the same routers just fine.

Telling us that airport works ironically perfectly under windows in Boot Camp puts the proof in the pudding. 10.4.8 on intel has destroyed airport, and Apple will not acknowledge it. I've had no problems whatsoever under 10.4.7 and earlier, and running an ibook on 10.4.8 simultaneously have had no problems. Besides the chip set, my hard drive on the intel imac, and the drive on the ibook are virtually the same.

Hmmm. I had no idea 10.4.8 was at fault, thanks for the info. Is there any way of rolling back to 10.4.7? It would be a real shame if I had to format my Mac just because of this. I haven't had to format and reinstall the OS since the day I bought it in March 2006.

 

[Queso]

Hmmm. I had no idea 10.4.8 was at fault, thanks for the info. Is there any way of rolling back to 10.4.7? It would be a real shame if I had to format my Mac just because of this. I haven't had to format and reinstall the OS since the day I bought it in March 2006.

To take that route would need you to re-install OSX from the disks that came with the Mac, then download the 10.4.7 combo updater from Apple. However, if you can hold off until 10.4.9 makes an appearance that would be the easiest route, although it would mean using your iBook's Internet Sharing in the meantime so it acts as a wireless bridge.

If this problem is as widespread as indicated above, I can't imagine Apple won't be including a fix in the next update, and we know 10.4.9 is undergoing testing.

EDIT: Saying that, just had a thought. Have you downloaded the 10.4.8 combo updater from Apple and installed that over the top of what you have? It may work.

 

[Compile 'em all]

Hmmm. I had no idea 10.4.8 was at fault, thanks for the info. Is there any way of rolling back to 10.4.7? It would be a real shame if I had to format my Mac just because of this. I haven't had to format and reinstall the OS since the day I bought it in March 2006.

I think he was suggesting that it _might_ be the fault of .8. I think the only way to make sure is to get someone with a Mac and running .8, and try to connect him to your access point. If it works then there is some setting not correct on your Machine, if not then it is a problem with OS X.

 

[thewhitehart]

To take that route would need you to re-install OSX from the disks that came with the Mac, then download the 10.4.7 combo updater from Apple. However, if you can hold off until 10.4.9 makes an appearance that would be the easiest route, although it would mean using your iBook's Internet Sharing in the meantime so it acts as a wireless bridge.

If this problem is as widespread as indicated above, I can't imagine Apple won't be including a fix in the next update, and we know 10.4.9 is undergoing testing.

I definitely agree that the OP should wait for 10.4.9, and hopefully they'll fix it. Rolling back did indeed require me to archive and install, and it took a good 3 to 4 hours to get everything back the way I wanted it (had to reinstall flip4mac, growl, and printer drivers, and tweak a few things). I then downloaded the 10.4.7 combo update from Apple's support site.

EDIT: Saying that, just had a thought. Have you downloaded the 10.4.8 combo updater from Apple and installed that over the top of what you have? May work, so worth a go.

I tried it, and it worked for a good five days, and then the problems started again

 

[Queso]

I tried it, and it worked for a good five days, and then the problems started again

Bugger. Still, five more days is five days closer to 10.4.9. Any chance we could see that released during MacWorld?

 

[nsheikh80]

The plot thickens.....

I finally decided to format my Mac an start over.

I used the discs that came with my iMac to restore the Mac back to it original state that came with out of the box (10.4.4) which had no problems connecting to my Wireless router.

However, the problem still persists! I have not done any update and not even copied my personal data across...all I have is a fresh install of OS X 10.4.4 and it refuses to get an IP Address. Someone please help!

 

[Queso]

However, the problem still persists! I have not done any update and not even copied my personal data across...all I have is a fresh install of OS X 10.4.4 and it refuses to get an IP Address. Someone please help!

Did you update the EFI firmware at any point?

 

[nsheikh80]

Did you update the EFI firmware at any point?

I just bought a new Linksys router. Plugged it in and my iMac is now connecting to the internet just fine.

I can't believe I formatted my Mac, I am so not pleased about this.

It doesn't explain why my old router wasn't working with my Mac but was working with all my Windows PCs but at least its now working!

 

[eluk]

This problem can be circumvented by assigning a fixed address. I first did this when I encountered problems with my original MBP. Since that time I've had no troubles with my wireless link.

 

[nsheikh80]

I just bought a new Linksys router. Plugged it in and my iMac is now connecting to the internet just fine.

I can't believe I formatted my Mac, I am so not pleased about this.

It doesn't explain why my old router wasn't working with my Mac but was working with all my Windows PCs but at least its now working!

I regret to inform you that late yesterday, the problem started occuring again. Airport won't pickup an IP address no matter what I do and I still have the new router in. I swapped out with the old one but no luck.

 

[nsheikh80]

This problem can be circumvented by assigning a fixed address. I first did this when I encountered problems with my original MBP. Since that time I've had no troubles with my wireless link.

I have tried to assign myself an IP address but unfortunately it is not allowing me to access the Internet. I have checked my router and it is issuing addresses via DHCP, could this be conflicting with my manual assigning of an IP address?

 

[eluk]

I have tried to assign myself an IP address but unfortunately it is not allowing me to access the Internet. I have checked my router and it is issuing addresses via DHCP, could this be conflicting with my manual assigning of an IP address?

It could be. How large a pool do you have set on your DHCP server? You could either make this smaller or simply set the fixed IP high, such as xxx.xxx.xxx.200. My fixed setting is out of the router (Belkin) range and works fine.