Hi. We are having a problem with dhcp, which is running on Win NT 4. We have Cisco 6500 switches on 7 subnets at this location. If a user shuts down and moves their laptop to another floor/subnet and starts up again, they do not get a valid ip address, they get a 169.x.x.x address. They must reboot, or disable/enable their network card to get a valid address for that subnet. If they do an ipconfig /release before shutting down, everything works fine. This is also a problem for people coming here from other offices, they have to reboot to get a valid address.
I can't find much useful info on MS's website, so I thought I would try here. Thanks for any information you can provide.
Make sure you don't have a broadcast address specified on your interfaces such as 169.X.X.255 , it doesn't need to be there and will keep dhcp from workly correctly . We had the exact problem and finally tracked it down to having a broadcast address specified ont the interfaces which interferes with the way DHCP works when people plug into the network without releasing the address . This cured the problem by removing the specified broadcast address .