My computer refuses to accept the IP-adress that is sent from the modem. Why?

[jaffa]

When I check my network connection my LAN-connection is listed with a red X and an error message saying that ?a network cable is unplugged? (no true in my opinion). I can see that my LAN-connection is flashing very briefly every 5th second (computer receives an ip-adress) but the red X returns immediately. For some reason my computer/network simply refuses to accept the ip-adress sent.

For your information:
My computer is connected directly to a broadband modem with the correct type of cable.
The connection worked great some days ago, but not anymore.
Have tried system restore without success.
Checked the status of the network cards in device manager. No question/exclamation marks.
Have uninstalled the network card and its (most recent) drivers and of course reinstalled it too.
No firewalls or any other potential internet obstacle is installed.
No new hardware or software has recently been added.
DHCP is enabled on the computer and should be so according to ISP. TCP/IP settings are correct.
Tried reseat network cable.
Tried another network cable.
Tried another network card.
Tried in another pci slot.
The ?sync, dsl. @? led on the modem is lit, indicating that the modem is working fine.
ISP says no problems in the network.

The only thing I have done (and is reluctant to try) is to reinstall the OS.

Any tips on what I should try next (before reinstalling everything and accepting that I can?t find the problem)?

 

[cleverhandle]

What output do you get if you do an "ipconfig /renew" at a command prompt?

 

[jaffa]

Then the computer sits on that screen for some time and then informs me that the requested action is not possible....

 

[JackMDS]

Under such a situation it is hard to know whether it is the Network Settings of your computer, the Modem, or your Internet Service.

You can go over your Network Configuration as described at the end.

However, if every thing turns OK you are back to square. One.

My personal solution to such a situation is to get a Cable/DSL Router. Beside the fact that it provides more secure and stable Internet connection (even for one computer) it makes it much easier to determine where in general troubles are (Routers can be found on sale for less then $25).

If you put a Router and you can Not connect to the Router from your computer then the trouble is with the computer. If you can connect to the Router and configure and there is No Internet then you know that it is time to call your ISP.

----------------------------------------------------
In General, you can debug the Network Settings of a computer by following these steps.

Step One. Check the Network parameters in the Computer's Device Manager. Make sure that the Network Card drivers are installed correctly; i.e. there is No IRQ conflict, and No Ghost installation. http://www.ezlan.net/faq#ghost

Step Two. Verify Basic network setting in the OS: http://www.ezlan.net/Installing#verify If the above two Steps indicates that every thing looks good but functionally it does not work.

Step Three. Check (and repair if necessary) the Socket Layers, Winsock, and or refresh the TCP/IP Stack. http://www.ezlan.net/clean#refreshnet

If need to Reinstall the Network Settings; Log to this page, it have a lot of links to instructions for Windows Network Installation - http://www.ezlan.net/Installing.html

:sun:

 

[promposive]

If you cant try another computer on it, and dont want to reinstall O/S, then download knoppix, and see if it works.

 

[bruceb]

Try this: ... 1): Do a hard reset of the Broadband Modem .. see your instructions that come with it
2): if this is windows XP, get a program called Winsockfix from here: http://www.majorgeeks.com/download4372.html
3): make sure you are using a Straight Thru Cat 5 cable and not a Crossover Cable

Also make sure your broadband modem is set to automatically assign an IP address ... if it does not
have this feature, then you will need to code in the Address in the Lan Connection Settings of the PC

Winsock should fix it

 

[yukichigai]

Originally posted by: bruceb
3): make sure you are using a Straight Thru Cat 5 cable and not a Crossover Cable

Actually, sometimes modems require a Crossover Cable rather than a Straight Cable. If you switched out the cable for any reason try going back to the one that came with the modem. If that's not possible try with both a Crossover cable and a Straight cable and see what happens.