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I'm using Windows Vista on a laptop, and while my wireless card works fine and takes the address the wireless router's DHCP server gives it, for some reason when I plug my (built-in) laptop NIC port into the router via ethernet, the IP address assigned to the NIC is something like -- nothing close to the address range the DHCP server is supposed to be handing out. It sounds like an old address I used at college whenever I plugged into the lab.

The NIC card is set to use auto configuration values for IP addresses --v4 and v6-- nothing hardcoded that I can see. I've tried several things (ipconfig /release, rebooting) to clear that address but nothing does the trick. Anyone know what I'm missing?

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up vote 6 down vote accepted

What you're getting is known as an APIPA address. This is basically a DHCP failover mechanism specific to Windows which automatically assigns you an address in the range - if it could not make an agreement with, or find, your DHCP server.

This could indicate a problem with your NIC or even the router. Check the router settings to ensure you are not filtered by MAC address for example. If you aren't using IPv6 for anything, see if disabling it helps.

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+1 for disabling IPv6 Have seen this give issues similar to the one you have – Dave M Jan 28 '10 at 20:45
Thanks for the help. Your guess about the MAC filter was spot on. I had my laptop motherboard replaced a few weeks ago, and a new hw address for the built-in ethernet was part of the package. – larryq Jan 29 '10 at 7:22

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