DHCP problem on new Macbook Pro 17

Discussion in 'MacBook Pro' started by engelhart, Mar 25, 2009.

  1. macrumors member

    Joined:
    May 23, 2004
    #1
    This is driving me nuts.

    Got my new macbook pro 17 unibody and love it. Turn it on, set it up to access my wireless and all is hunky dory for a few days. One day, it goes to sleep, comes back out of sleep and refuses to connect to my network. Says has self assigned IP.

    So I do all I can think of, check all the other macs are working with the Airport Extreme base station and they are, reset it anyway, and still no luck. Try connecting to another wireless network a neighbour has and it works fine. Try to connect to mine, either won't connect at all or self assigned IP. Try again with old macbook pro next to me and it connects fine.

    Then a day later, it randomly works for a few hours. Now it doesn't again even though everything else does.

    I'm tearing my hairout, I can't come up with any reason why this is happening when the router is fine and allows the other Macs to connect and the new Mac will connect to other wireless networks but not the one here.

    Please, someone tell me they have a solution!
     
  2. macrumors member

    Joined:
    Mar 19, 2009
    #2
     
  3. macrumors 68040

    iLog.Genius

    Joined:
    Feb 24, 2009
    Location:
    Toronto, Ontario
    #3
    Hah, you know, whenever you have "self assigned IP" problem RARELY is it a serious problem. First, could be the modem, just because others are fine, doesn't mean the router is free of errors; power cycle and see what's up. If you're still getting the same error, create a new location. If that still doesn't fix the problem, .plist removal will likely fix your issue. This is something that doesn't require you to go to the Apple Store.
     
  4. macrumors regular

    Joined:
    Mar 8, 2009
    #4
    Good to know because I am having this same issue. I figured it wasn't serious, but everytime I go to campus and try to use the Wifi it won't work until I restart the airport 30 times and log off and on, and then it finally connects instead of saying "self assigned IP".

    How do I remove the .plist?
     
  5. thread starter macrumors member

    Joined:
    May 23, 2004
    #5
    I've removed the .plist to no avail, at least the one if library/preferences/ that mentions airport.

    As a test, I asked my landlord for his password to connect to his airport. Won't work either, seems that my Mac will only connect to non-Apple routers!
     
  6. macrumors regular

    Vikz

    Joined:
    Nov 13, 2007
    Location:
    San Juan, Puerto Rico
    #6
    actually, from what I have seen, its a bug on leopard since the last update, it has happened to my head tech and a few client's machines while we are making updates and other stuff on the internet and the machine goes to sleep or shuts down

    my head tech made a chat with engineering but they told them they would check that out...

    so all of the people that come with that problem to the service center i work, are told to wait for 10.5.7
     
  7. macrumors 68040

    iLog.Genius

    Joined:
    Feb 24, 2009
    Location:
    Toronto, Ontario
    #7
    No bug, happens in 10.5, 10.4 and in 10.3. Small error/confusion, nothing that can't be fixed at home.

    Let's troubleshoot this...

    1. Power cycle modem/router (disconnect power for at least 2 min.)
    2. Create a new location (System Preferences>Network>Location>New Location), Apply Now/Reboot
    3. Create a new user (to isolate your preferences or system wide)
    4. Remove .plists (Macintosh HD>Library>Preferences>SystemConfiguration:com.apple.airport.preferences.plist AND preferences.plist) Make sure you move to trash and it's removed from the folder
    5. Restart.

    Also, happens to a lot of users. If you are using VOIP you need to remove the battery in the modem for it to properly reset. Most customers are not aware of this!
     
  8. macrumors member

    Joined:
    Mar 19, 2009
    #8
    Well I've certainly determined that the problem is related to my router and/or modem at home. I had only been experiencing this DHCP problem on my newest MB Pro at home. It would still connect at work.

    Then last night while trying to troubleshoot the new machine my other three machine's at home started having the same DHCP problem whereas they had previously been error free.

    The machine I'm using now was showing the DHCP error at home last night and works fine here at my office this am.

    So this has to be a problem within either my Netscreen router or the Comcast modem. I tend to believe it's probably the Netscreen since I'm pretty sure it's the unit that supplies my DHCP.

    I tried all the remedies suggested in this thread last night and none of them resolved the problem.
     
  9. macrumors newbie

    Joined:
    Mar 26, 2009
    #9
    May be this help you: In network's preferences remove your wifi site, then goes to your keychain and remove keys from your wifi (there're 2 keys, in system and other place, not remember the name, newby in leopard's world). After that try to find and conect again, writing network's pass.

    Oh, yes, open the key before remove and show the pass to copy it.
     
  10. macrumors 68040

    iLog.Genius

    Joined:
    Feb 24, 2009
    Location:
    Toronto, Ontario
    #10
    This would be the same as created a new Location. It starts off "fresh" so you don't need to remove anything.
     
  11. thread starter macrumors member

    Joined:
    May 23, 2004
    #11
    Just tried this twice, no luck whatsoever. All other computers still work with Airport. Mine won't but will work with Neighbours non-Apple router (but not with other Neighbours Apple router).
     
  12. macrumors 68040

    iLog.Genius

    Joined:
    Feb 24, 2009
    Location:
    Toronto, Ontario
    #12
    Ok, what happens when you directly connect to the router? Same DHCP error? Also, try running Network Diagnostics, it might have some information that could help us out.
     
  13. thread starter macrumors member

    Joined:
    May 23, 2004
    #13
    Yes, same DHCP error as before.

    I've also tried just inputting the information in manually. It grabs the IP but still won't connect to the Internet. When I try to run network diagnostics when I'm connected to it, it just hangs.

    I've noticed that if I'm connected to it, if I then go to change to another wireless network that it refuses to scan or won't find anything. I have to turn airport off then on again, to be able to search for stations.
     
  14. macrumors 68020

    Joined:
    Apr 26, 2003
    Location:
    California
    #14
    I'm jumping in mid stream. My MacPro is the only Mac having Airport network issues - symptoms as others have described. Due to work demands I had to pass on the trouble shooting and now have cat 6 ethernet cable strung from my AEBS to the back of my MacPro - works perfectly. That is COMCAST modem to AEBS to MacPro via cat 6. The AEBS continues to perform flawlessly with my other Macs.

    So......... not sure if that provides any diagnostic help but it has me productive again.
     
  15. macrumors 68020

    Joined:
    Apr 26, 2003
    Location:
    California
    #15
    The turning Airport on - off - on - off worked for awhile. It no longer connects at all. My Airport card shows up in the 'About this Mac" section.

    ??????
     
  16. macrumors 68040

    iLog.Genius

    Joined:
    Feb 24, 2009
    Location:
    Toronto, Ontario
    #16
    Strange...we can rule out hardware failure, no way your AirPort and Ethernet port has failed. Since you tried in new user it something system-wide. Has to be something in your preferences folder or the modem itself. Have you tried to renew your DHCP? Usually the .plist or the power cycle fixes those problems. Are you sure you deleted the plist from the folder and made sure that they were removed when you deleted them? Have you tried restarting in safe mode?
     
  17. macrumors member

    Joined:
    Mar 19, 2009
    #17
    Well my DHCP problem is solved. It was a bad cable between my router and hub. Can't believe I didn't check that sooner.
     
  18. thread starter macrumors member

    Joined:
    May 23, 2004
    #18
    So just after you posted this message, suddenly I could connect to my Neighbours airport extreme and then I could connect to my network. I was about to post with a whoopee but remembered my last experience of it suddenly working and thought I'd give it a while to see if it lasted.

    Sure enough, computer went to sleep again while I was watching TV and we are now back to the dhcp errors on Apple base stations, whilst still working on non-Apple.
     
  19. macrumors 68040

    iLog.Genius

    Joined:
    Feb 24, 2009
    Location:
    Toronto, Ontario
    #19
    Weird situation you're in. Have you tried to do a hard/factory reset of your AirPort base station? And do you use VoIP? If you're able to connect to your neighbors, it has to do with your setup, specifically modem and or AirPort Base Station. Who is your ISP?
     
  20. macrumors regular

    Vikz

    Joined:
    Nov 13, 2007
    Location:
    San Juan, Puerto Rico
    #20
    very insightful thread.

    hmmm... only with aiport base stations? wierd, I get with the linksys i have at home and sometimes with the neighbors dlink
     
  21. macrumors 68040

    iLog.Genius

    Joined:
    Feb 24, 2009
    Location:
    Toronto, Ontario
    #21
    I created a PDF on how to troubleshoot network problems and added it as an attachment. It's the same as what has been discussed already but a little more detail. So those who are having problems, take a quick look and see if that will help. These are exact steps we use at work and it is almost always successful in repairing user problems.
     

    Attached Files:

  22. macrumors newbie

    Joined:
    Dec 27, 2008
    #22
    This is not a problem with the Airport Base Station. I have this problem, same machine, brand new Macbook Pro 17 unibody.

    If the machine goes to sleep, my ethernet connection dies. IP is lost. Will not fetch new address via DHCP. If I unplug and replug the ethernet cable, this sometimes helps.

    Turning airport off and on will also do the trick if I am on wifi.

    In this case, the router is pfSense - a BSD based router.

    In my case, this problem began when I installed 10.5.7. It did not happen with 10.5.6 (which came with the machine).
     

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