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I have noticed that my laptop disconnects from router once or twice a week and then waits before connecting again. It is like i have been disconnected from router manually. Router works as usual however. Why is that so? Maybe lease is expiring or something?

Additional Details:

Latitude E6420, Windows 7 Enterprise, 3Com OfficeConnect Wireless 11g Cable/DSL Router (latest firmware), DHCP server.

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Please Note: I get the following message in EventViewer everytime this happens:

"The IP address lease for the Network Card with network address 0xEC55F95E05CA has been denied by the DHCP server (The DHCP Server sent a DHCPNACK message)."

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From talking to you in chat and more, my suggestion would be to set a static IP on your machine and see if this fixes the problem.

From the details you have given, it looks like your laptop is working fine and is sending a DHCP request when scheduled to, but, your router is not responding correctly/not permitting you to renew your lease.

As for why, in all honesty, this is one of the problems that drives people mad. You can try updating your wireless drivers on your laptop on the off chance that it will fix it, but I doubt it.

Your router is a good 6 years old now. I remember when Windows Vista first came out, there was a lot of incompatible routers due to DHCP problems. I believe this was caused by updates to the network stack, however, I never followed this up and can not find any reports of it, so I can not confirm if this is related.

If you have other hardware you can test, I would try and see if you get the same problems with other things. If you do - it is a problem with your router. If you don't, it is a compatibility problem between your computer and the router.

In any case, if this is a router provided by your internet service provider, you may want to try to ask them if they offer an upgrade/newer model.

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William i have changed routers IP, i have disabled DHCP and still i get disconnections. I experienced disconnections on laptop and on smartphone. – Boris_yo Aug 16 '11 at 12:20
It isn't about disabling DHCP, it is about enabling static IP on your devices. If you are still getting disconnections after this though, then, I think that the DHCP messages in your event log were not relevant and your router has bigger problems... Out of curiosity, do you reboot your computer or the router to fix the problem usually? – William Hilsum Aug 16 '11 at 12:43

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