DHCP renewal suddenly started to fail with WPA-WSK

Giganews Newsgroups
Subject: DHCP renewal suddenly started to fail with WPA-WSK
Posted by:  Mark Wilson
Date: Wed, 28 Dec 2005

I have a D-Link DWL-2000AP+ configured to use WPA-PSK.  After I initially
configured this, all of my (Windows XP SP2) clients were connecting fine, and
receiving IP addresses from the (Windows Server 2003 SP1) DHCP server (lease
time 1 day).  Then, two days later, as each lease came up for renewal they
failed, one by one.  This means that they all renewed successfully after the
initial WPA-PSK configuration, but have failed to do so even since.

Because of cabling issues in my building, the DHCP server has two network
interfaces - one wired LAN connection for computers near the server (this is
issuing IP addresses with no problems) and a wireless connection (a D-Link
DWL-520+ PCI adapter) back to a the access point and another wired subnet
upstairs (this is the one with DHCP problems).  I have checked the bindings
and the DHCP server is bound to both adapters (as it has been ever since the
server was rebuilt a couple of months back).  IP forwarding is also enabled
on the server so the two subnets effectively become one.

If I set static IP addresses on the upstairs LAN, both wired and wireless
clients can connect (and use the wireless network to access the server
downstairs); however I would like to go back to using DHCP and can't see what
went wrong!

There are no errors indicated in the DHCP logs, and nothing obvious in the
event log either.  I've carried out a network trace (using a wired
connection, which is then forwarded by the access point to the server's
wireless interface) and can see the DHCP Discover (x4), but no replies (is
this because of the encryption?).

I can't use WPA2 (because the AP doesn't support it), and will not use WEP.
This solution did work for about 48 hours before it all started to collapse!
I'm pretty sure it's nothing I did because it started to go wrong over the
Christmas holidays when the computers were on but no-one was using them!

TIA, Mark