Airport-has-a-self-assigned-IP-address

Fix: Airport has a self-assigned IP address

Fix: Airport has a self-assigned IP address, 169.x.x.x and Subnet Mask: 255.255.0.0. I could connect to my Time Capsule, though it did not get a IP address by the DHCP server. I tried everything to fix: Airport has a self-assigned IP address. I tried renewing the DHCP but that did not work. I also tested for DNS error, this was not the case either. My mac gave me this message “Airport has a self-assigned IP address and may not be able to connect to the internet.

Assessing the problem “airport has a self-assigned ip address”

I fixed the problem “airport has a self-assigned ip address” by manually setting up the network settings, to make sure they matched my own in, DNS Server, Router, Subnet Mask, and IP address +1. That worked but this could only be a temporarily solution as she uses her mac multiple places.

So I adventured out into the great indexed space of google to find a solution to the problem. As it turned out quite a few people was addressing the problem, and it seems to be a problem that Apple have had this problem for quite a while. In my search I found the problem has occured in an update to Apple OS X Leopard somewhere between update version 10.5.2 and 10.5.6. While the mac in question is at OS X 10.5.8 the problem still seems unsolved by Apple.

To fix “airport has a self-assigned ip address” I tried the following.

1. Booting into SAFE BOOT by restarting the mac and pressing the shift key.

2. In safe boot deleted the SystemConfiguration folder in this location:
Macintosh HD>Library> Preferences

This folder contains information from the System Preferences, and will be reconstructed if it is not found in the path. In my case it contains the following files, that I found should be deleted if I could not remove the entire folder:

  • com.apple.airport.preferences.plist
  • com.apple.network.identification.plist
  • NetworkInterfaces.plist

3. I opened Keychain Access and found all the information about the network I was trying to access, and removed the login information by deleting the key. It appeared both in login and system. You can access Keychain Access, by opening Spotlight and type Keychain Access (this even works if your system is configured for another language than English).

4. Restarted the mac and voilár it worked…..but only shortly after a test restart the problem was back on again.

Fixing the problem “airport has a self-assigned ip address”

I finally found the solution which was very simple. The solution in this case was to:

  1. Turn off Airport
  2. Switch off the built-in firewall (found in: System Preferences>Security>Firewall), I set it to allow all incoming connections.
  3. Turn Airport back on again….and it worked

I tested this solution to work, and it worked after a restart as well. I have no clue to what caused the problem, however, I hope that this information will be of value to others as well.

46 replies
  1. Gregg
    Gregg says:

    Hey Philip, thanks a lot for your post. If anyone else has this problem they should note that no steps should be skipped! I didn’t do the keychain step and it didn’t work so I had to go back and do everything over. My firewall was already off so I turned it on and then off again just to be sure.

    I got tired of looking in all the forums where everyone had an opinion but no one had a solution. These Mac Forums (MacForum especially) are getting ridiculous. You have people piping up that have nothing to offer except hot air and a hunch.

    Thanks for you straightforward, step-by-step solution. A real solution…

    Gregg

  2. ann smith
    ann smith says:

    This is what worked for me. None of the other solutions worked. If you are able to> go to system prefs>network> advanced? TCP/IP >using DHCP and choose use configure DHCP manually. If you are on a network get a static IP number and use that. apply changes and restart.

  3. Anna
    Anna says:

    Hey, thanks for this post….I’m having the same problem and would like to try this but not sure how to do the keychain access bit? Where would I find this on the computer?

  4. Iain
    Iain says:

    I’m incredibly grateful for this solution, but after having followed every step (twice), I’m still running into the same problem.

    Looks like I’ll just have to keep scouring Google until I find a solution that works for me… *sigh*

  5. Philip
    Philip says:

    Well you could try and look for it in Applications>Utilities and then select Keychain Access. Though it will probably have a different name if you use another system language than english.

    Hope that helps

    /Phil

  6. Sandra
    Sandra says:

    Thanks so much for posting your solution which worked after a very frustrating day! So glad my iPad allowed me google you while my mac was unable to connect to the server!!!!

  7. Kalyan
    Kalyan says:

    I recently switched to comcast internet and boy my wireless network will not get set up at all.
    I tried many different combinations the so called power cycle, re-creating wireless network interfaces, trashing the plists and network config files and nothing worked for me. I would end up with the annoying “Self assigned ip” message.

    Then I got the idea of reseting my Time Capsule configuration and it worked and pushed me into party mode. :)

    1. Reset your Time Capsule / Airport Express
    2. Open Airport Utility
    3. Create a new wireless network (with a different sid)
    4. Set up password…. and continue the steps as you have done in a previous set up.
    5. From your Mac or other devices, select the newly created wireless sid.

    This worked for me after hours of battling with my Time Capsule.

  8. The Mac
    The Mac says:

    You are a genius! Saved me a bunch of trouble cause I was messing around with my router, and somehow got to the original problem. Only hint I would give is to delete the Keychain Access in regular not boot mode, the spotlight wouldn’t work for me in boot mode. Thanks. Keep being awesome!

  9. Afarnti
    Afarnti says:

    I have a MacBook Pro with 10.6.8 crashing and then failing to connect to airport with this error. Tried the process (and other tricks discussed on the web) and none worked. At the end, I tried to turn off WEP authorization of the wireless router. The macbook finally was able to get an IP. I then setup the WPA authorization on the router and no problem either, which is the setup that I am using now. I guess the lesson here is that this is apparently a “weird” error and one just has to try whatever has worked for others until finding a solution.

  10. Jono
    Jono says:

    Thank you so much, I have struggled so long searching the apple web site to no avail! THANK YOU SO MUCH! I thought my ISP needed to give me seperate IP and so many guesses never worked, so may configurations never worked, until NOW! You truly are a nice guy DANKE!! Ich bin Ihnen sehr dankbar!!

  11. Lordi1408
    Lordi1408 says:

    Thank you so much! The only thing that was different for me, was once I completed all the steps, I had to go back and re-enter the original WEP Key instead of my old password. Otherwise thanks! You saved me a HUGE hassle!

  12. andrew
    andrew says:

    Solution may be even simpler!
    I tried several of the above solutions that seemed less extreme to no avail.
    Then I went into the Airport Utility, Clicked on the Internet tab at the top, under Internet Connection, my airport had been set to Bridge, I changed this to ‘Share a Public IP Address’.
    One of the above comments got me thinking on those lines where a user mentioned that you cannot get a static IP on some networks.
    I do not fully understand what all of this means, nor have I tested my ability to connect other computers or my Sony Playstation to the network… but at least Im back online with my primary computer!

  13. SP
    SP says:

    One thing that I found was my IP range was only set on my Netgear wireless router to support 10 devices (from 192.168.0.10 to 192.168.0.19), which wasn’t enough. I increased the upper range to 192.168.0.50 and now everything seems to work fine.

  14. Darren
    Darren says:

    Your ‘solution’ has not fixed my problem. I have deleted keychain files then deleted system configuration folder, flushed the DHCP cache, deleted all references to ‘old’ connections, restarted, zapped the PRAM and NVRAM, reset the modem. None of this has worked. Any and all help is greatly appreciated.

  15. Anonymous
    Anonymous says:

    Man, I was worried about having to take days to fix this, but the firewall thing totally worked. Thanks a bunch. (Yeah, I’m replying to a post from 2010, but I’m sure you’ll read this comment)

    • Philip
      Philip says:

      Happy to know that it helped =) And ppl are still using this guide to solve the problem. I think it must be Apple related as I have not have this problem since I switced my Airport with a Netgear router.

  16. Steve S
    Steve S says:

    I found that this can also happen if the IP address that the DHCP server assigns is already in use by another device on the network. In my case, I had assigned an IP address in the DHCP server based on the MAC address of the Mac Mini. Someone else on the network has apparently used that IP address as a static assignment on their device. Now it’s time to hunt down that device!

  17. Sami
    Sami says:

    Thanks a million!!! I wasn’t able to find terminal (older version apparently) but I cleared the key chain and completed the last step and am so VERY grateful I stumbled along this page!!! Thank you thank you THANK YOU!!!!!! Eeeep!

  18. angela
    angela says:

    THANK YOU! I’ve been going insane trying to fix this issue. Yours was the only fix that worked, and it worked instantly. Turned airport back on, and I’m back online. Worked much better than chucking it through the window like I wanted to do.

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