+ Post New Thread
Results 1 to 9 of 9
Windows Thread, Laptops retaining IP when cable not connected in Technical; Hi Guys I'm having an annoying problem with a whole bunch of the laptops on our network. They will come ...
  1. #1
    Nick_Parker's Avatar
    Join Date
    Jan 2008
    Location
    Dainfern, South Africa
    Posts
    440
    Thank Post
    95
    Thanked 18 Times in 13 Posts
    Rep Power
    17

    Laptops retaining IP when cable not connected

    Hi Guys

    I'm having an annoying problem with a whole bunch of the laptops on our network.

    They will come to me and tell me that its not connecting to the network,
    I'll ipconfig it, and it'll have DHCP IPs assigned to both the WiFi Connection and the Ethernet Connection, even tho the cable is unplugged...

    If I ipconfig /release and ipconfig /renew the machine, the Ethernet Connection is then assigned a 0.0.0.0 address and the WiFi Connection picks up a new address and everything works.

    I can't remember now if the icon for the ethernet cable shows that the cable is unplugged or not, but I know it's not a hardware issue, because alot of the notebooks are doing it.

    Has anybody else experienced anything similar? It's like windows isn't checking the connection and isn't detecting that the connection is lost?

    Any help or suggestions would be greatly appreciated!

  2. #2
    leco's Avatar
    Join Date
    Nov 2006
    Location
    West Yorkshire
    Posts
    2,026
    Thank Post
    595
    Thanked 125 Times in 119 Posts
    Rep Power
    41
    I had that issue a while ago. From memory I had to plug the laptop into the network so that the wired network automatically gained an IP address. The wireless card would then kick in and gain an IP as well. I think that the network cable is unplugged message popped up, but am not sure on that.

  3. #3

    Michael's Avatar
    Join Date
    Dec 2005
    Location
    Birmingham
    Posts
    9,262
    Thank Post
    242
    Thanked 1,572 Times in 1,252 Posts
    Rep Power
    340
    I can't remember now if the icon for the ethernet cable shows that the cable is unplugged or not, but I know it's not a hardware issue, because alot of the notebooks are doing it.
    Yes, Windows will display a network icon both for Wireless and Ethernet with a red cross. When an IP is obtained, the Ethernet icon disappears, but the Wireless icon changes and flashes when there's activity. This is the default behaviour, but you can change it in Network Properties.

    Have you tried updating the driver for both network adapters? Seems odd it "remembers" its IP when a cable is disconnected.

  4. #4

    RabbieBurns's Avatar
    Join Date
    Apr 2008
    Location
    Sydney
    Posts
    5,527
    Thank Post
    1,339
    Thanked 470 Times in 307 Posts
    Blog Entries
    6
    Rep Power
    200
    do they alternate between wired and wireless connections or are they only everc onnected wireless?

    why not just disable the wired connection?

  5. #5
    Nick_Parker's Avatar
    Join Date
    Jan 2008
    Location
    Dainfern, South Africa
    Posts
    440
    Thank Post
    95
    Thanked 18 Times in 13 Posts
    Rep Power
    17
    I think its the latest drivers, I will make 100% sure tho.
    They use both wired and wireless,
    when they are working in their classrooms, they use the wired connections (point in every classroom) but when they go into areas like the library, staffrooms etc... then they use wireless...

    But, they go into an area with wireless, I *THINK* DHCP assigns the wireless an IP address (i'm not sure on the order these things happen, they always come to me after its happened) but the wired card still has an ip address assigned to it and the computer tries to use that instead of the wireless connection.

    ipconfig /release and ipconfig /renew

    The wired ip address disappears and the wireless one renews itself and everything is fine, until they go and plug it into their classroom again, then I think it retains an ip for the wireless (even tho they are out of range)...

  6. #6
    Nick_Parker's Avatar
    Join Date
    Jan 2008
    Location
    Dainfern, South Africa
    Posts
    440
    Thank Post
    95
    Thanked 18 Times in 13 Posts
    Rep Power
    17
    I have attached 2 pictures here to show you what I mean,
    The first picture "Network_Settings" shows that even tho the lan cable has been unplugged, windows doesn't seem to detect this and still has an ip address assigned to this interface. Even tho the wireless connection is connected and active, nothing on the laptop will connect via the network (I suspect it's still trying to communicate via the lan connection).

    Picture "Network_Settings2" shows what happens when I do a "Ipconfig /Release"

    Both interfaces are assigned IP addresses of 0.0.0.0

    Surely windows should detect that the lan connection is not connected and not assign it any address at all?

    When doing an "ipconfig /renew", the wireless connection gets a new IP address within seconds and begins communicating, however the process seems to freeze for 30 seconds, I'm guessing it's *trying* to get an IP address via DHCP for the Lan connection even tho it's not connected.

    Anyways, any suggestions would be appreciated
    Attached Images Attached Images

  7. #7


    Join Date
    Feb 2007
    Location
    Northamptonshire
    Posts
    4,692
    Thank Post
    352
    Thanked 797 Times in 716 Posts
    Rep Power
    347
    Weird ... sorry no help here just wanted to post at how odd that is

  8. #8

    Join Date
    Jan 2006
    Location
    Surburbia
    Posts
    2,178
    Thank Post
    74
    Thanked 307 Times in 243 Posts
    Rep Power
    115
    The fundamental problem is that XP should be saying "Media disconnected" when the cable isn't there. I'd probably blame the driver, but the first thing to check is that you do NOT have this in the registry:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Servic es\Tcpip\Parameters
    DWORD: DisableDHCPMediaSense 1

  9. Thanks to PiqueABoo from:

    Nick_Parker (11th February 2009)

  10. #9
    Nick_Parker's Avatar
    Join Date
    Jan 2008
    Location
    Dainfern, South Africa
    Posts
    440
    Thank Post
    95
    Thanked 18 Times in 13 Posts
    Rep Power
    17
    Thanks PiqueABoo,

    I'll have a look and see, the odd thing is, there are ALOT of laptops doing it and they're all using the latest drivers.

SHARE:
+ Post New Thread

Similar Threads

  1. Is box connected to (the right) LAN?
    By PiqueABoo in forum Scripts
    Replies: 9
    Last Post: 9th October 2008, 11:18 PM
  2. Imaging an AD-connected machine
    By Daleus in forum How do you do....it?
    Replies: 12
    Last Post: 23rd September 2008, 10:15 PM
  3. Replies: 8
    Last Post: 9th November 2007, 01:33 PM
  4. Replies: 8
    Last Post: 1st February 2007, 08:42 AM
  5. How are your mac's connected ?
    By daveyboy in forum Mac
    Replies: 11
    Last Post: 16th July 2005, 01:52 PM

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •