# DHCP/Self-Assigned IP address/Airport problems -- HELP!



## intensebeet (May 4, 2006)

I have been searching everywhere for a solution to this problem all to no avail and so I was hoping that someone here would have some advice to offer.  I am running an iBook 600 with OSX 10.3.9 and an airport card.  Also on my home network are a laptop running XP and a desktop running windows 2000pro.  All three of these machines connect wirelessly to our linksys router model BEFW11S4 which is wired to our cable modem.  Also on the network is another wireless media device (Roku m1001) and an xbox which is the only device directly wired to the router.

I frequently am having trouble conecting to the internet.  My signal strength will say excellent but when I open Network Preferences, it tells me that I may not be able to connect to the internet because I am using a self-assigned IP address.  Another consistent problem is that when I turn on my computer it takes the IP address from another computer already on the network and knocks that computer off, my internet usually works at this point.  When I am having dificulties connecting and I check my settings it usually has either a very odd IP address assigned that is not used by this network, or no IP address at all being shown.  Trying to configure this manually does not seem to help.  

My final question relates to DHCP; running it seems to mess with the windows PC's on the network and when we turn DHCP off in the router settings my iBook seems to have no way at all to figure out how to connect to the internet.

I use my laptop on my school's wirelesss network with no problems at all and can connect to my parent's wireless network (2 PC's) easily as well, the problem only seems to be here at home.

This problem is becoming increasingly frustrating lately and the only solution seems to be to completely reset our modem/router and/or turning off one of the computers on the network.  Any help or advice would be greatly appreciated at this point.


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## sgould (May 5, 2006)

Have you got more than one device trying to issue IP addresses?


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## cmikes (Feb 16, 2008)

I've been having problems with this for months and finally found the solution on the discussions.apple com forums.  Based on a hint in a post there I changed the wireless security from WEP to WPA personal and entered a passphrase of more than 13 characters (that apparently is the key). 

Once I reset the wireless connection on the laptop and logged in with the new password and security mode, it suddenly was able to get an IP address and connect to the internet again. 

Finally.

mikes


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## Satcomer (Feb 17, 2008)

cmikes said:


> I've been having problems with this for months and finally found the solution on the discussions.apple com forums.  Based on a hint in a post there I changed the wireless security from WEP to WPA personal and entered a passphrase of more than 13 characters (that apparently is the key).
> 
> Once I reset the wireless connection on the laptop and logged in with the new password and security mode, it suddenly was able to get an IP address and connect to the internet again.
> 
> ...



Please share this with other people.


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## pazzmore (Jan 21, 2009)

Was having the same problem... on my laptop and lab desktops... however, only when connecting through my airport network and not the school's wireless.

I went and changed the password to a WAP Personal and made a 26 digit password...

and it is currently pulling correct IPs. Will it last? We shall see.


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## cmikes (Jan 21, 2009)

Sorry I didn't post this sooner. 

Go to the Network control panel, select the Airport tab. There will be a list of the wireless networks you have joined in the past. Select the network you are having trouble logging onto and click the edit button. Edit the parameters and close. You should be good to go.

Using the Personal WEP password turns out not to be good because it won't hold the password once the laptop goes to sleep. You have to keep rejoining the network and entering the password. Not fun.

Editing the network parameters seems to work.


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## alms02 (Jan 25, 2009)

Tried changing the WPA personal password to 26 characters.  The password is connected, it shows under the AirPort that I'm connected to my home network but when I try to open up Safari, it says I cannot connect to the internet. In network preferences under AirPort it says I don't have an IP address. 

When you say change the network parameters, what exactly are you referring to?  Thank you!


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## hellrazor4ever (Apr 16, 2009)

Hi everyobdy. I kept having the exact same problem (it looked like I was connected to the Access Point but didn't get a proper IP adress). Have Mac OS X 10.5.6 with newest (16/04) software updates for Airport. Long story short: TRIPLE CHECK THE WEP PASSWORT you entered. Finally, I had indeed a spelling mistake. Everything works fine now.


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## ElDiabloConCaca (Apr 16, 2009)

hellrazor4ever said:


> ...TRIPLE CHECK THE WEP *PASSWORT* you entered. Finally, I had indeed a spelling mistake....



However could that have happened?  I'm shocked!


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## s0methingrare (Jul 2, 2011)

Hi all,
My wife and I have been going through this same issue for two days. She called her tech support guy and he said:

1. Turn off the airport
2. Hold down the power button to power down the machine
3. Turn on the machine
4. Turn on the airport

And it worked! He explained, get this, that the machines sometimes carry too much static electricity and that interferes with the airport connectivity. Turning off airport and forcefully powering down the machine by holding in the power button discharges that electricity. I am in disbelief but whatev, she's back in business.

So if your firewalls are all disabled, router is in check, don't feel like visiting the mac store, and you are still getting this problem on your macbook, give this a shot.


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## siralexd (May 26, 2012)

I really didn't expect this to work but having sat for over two hours and fiddling around with settings, I was getting desperate and I tried this.

IT WORKED! That is sooo random! Apple has to fix this static electricity issue in their coming laptops. I have a MacBookPro 15" 2011 so it's quite new.

A BIG thank you for sharing this S0methingrare!

/Alexander


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## DeltaMac (May 26, 2012)

What a load of BS!
The forced power off has virtually the same effect as a System Management Controller (SMC) reset.
http://support.apple.com/kb/HT3964
That's the fix - not some bogus "static electricity" issue...


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