single segment lan, netware dns/dhcp running on nw6.5.3.

dhcpsrvr.nlm 3.13.04 single internal subnet, 192.168.1.x. DHCP is set to
lease out 95-254.

got a couple of workstations...both recent dell laptops
(hmmm...coincidence?). xpspk2, broadcom nics, current drivers. All of a
sudden, they can't seem to talk dhcp w/ my netware server. They don't get
an address during bootup, so they can't log in. "ipconfig /release/renew"
fails. (unable to contact your dhcp server, request timed-out...). If I
set an ip address manually, everything works fine. so the hardware is all
working. If I do an ipconfig /renew from other workstations, they renew
just fine. (released first to clear out the address, then renewed).

These laptops have wireless nics in them, and some neighbor has their access
point setup w/ no security, so they can and do connect to it, get an address
via dhcp, and are able to surf the internet through that. I disabled the
wireless in case it was interfereing with the hard-wired nic, but it makes
no difference. it does seem, though, that the ip stack is functioning
properly on the laptops.
but they can't seem to talk to the netware server.

I Unloaded and re-loaded dhcpsrvr on the server. no errors. even did a
dsrepair. still not working. Only other thing I can think to do is to
reboot the server entirely, which I like to avoid during working hours.
These laptops have been on the network via dhcp-issued addresses before;
nothing I can think of has changed in anyone's configuration. I'm at a loss
as to why they would suddenly stop working.

dns/dhcp server console says that there are addresses available.