DHCP problem on Domain

I have a 50 machine network. Yesterday, the server's network card failed. The server had a second network card that was not being used. I reconfigured the server so the IP address on the failed card was assigned to the unused card. Then, I connected the network cable to the good card. Most of my network computers started and connected just fine. A couple had problems with renewing the lease. I turned these off for a couple of minutes and then they connected ok.

All of the computers on the network are Win2k or XP Pro machines. The Win 2k server that failed was the domain controller.

BUT ... I have 2 workstations that will not cooperate, and I'm afraid that more will join that camp. Ipconfig shows the IP addresses for both of these machines as being their hardware address ... i.e. 169.x.x.x. I've tried turning the machines off, renewing the connections, etc. Nothing seems to work. At the moment, I have both of the machines running with fixed addresses. One of these computers worked fine yesterday, when the server card swap was made. But today, it's gone.

I'm afraid to try restarting the server ... I don't want to take a chance on losing everyone.

What did I do wrong?

 

169.x.x.x is the APIPA range that a machine will give itself when it knows there should be a DHCP server out there somewhere but can't see it.

Assuming that you are running DNS to resolve name<->IP address, purge the DNS records for the machines that are having problems. Then reboot them and see if they are cured. If not, 2K/XP have the option in their network settings to force a DNS record update so do that.

You may have a few issues with the server since there are a few places where the IP address and the MAC (hardware) address of the NIC are matched and recorded. The new NIC has the same IP but a completely different MAC and since that is burned into the hardware, you can't change it.

Do you have another 2K server on the domain? If so, DCPROMO to make it a domain controller would probably be an excellent idea. Always best to have two on each network segment. Unlike the 'bad old days' of NT4 when the original server build had to be either DC or server, a 2K server can have it's role changed without causing problems.

 

Good suggestions. I'll try them in the morning (California time). I can't move the DHCP server, because we have a Small Buisiness Server license, even though there are other servers on this network.

I'll try removing the DNS records from the server to see what happens. I can try stuff in the early morning, as long as the system is up and running when the real workday starts.

Thanks for the suggestions.

 

Solved

When I disabled the 3com card that failed, and enabled the other card, W2k server does not automatically switch the dhcp service to the new card ... even though it is the only card in the machine. Rebooting the machine didn't help, nor did resetting the network switches/hubs.

It turns out there is a KB article on this subject ... once you find the error # ... which is 1041. In my case I needed to select the dhcp server->properties->advanced->bindings. The only active card in the machine was not bound to the dhcp service. Once I did this, everything began to work again. Good thing too, since I apparently didn't have a working dhcp server ... even though it said it was working normally. And, more machines failed today, and more would fail tomorrow, etc.

If you lose a network card in a multihomed w2k server, there is apparently a bunch of stuff you need to do, and none of it is documented for the user (at least to my knowledge). I went through dozens of articles, a couple of books, and two forums. I think this is one of the weaknesses of windows. With unix/linux you can read through the kernal source (as disagreeable as that is) and find/fix errors. Windows is essentially a very complicated black box. If you miss a subtle point, you won't get anywhere. Enough editorializing, already

Thanks for the suggestions Newt. They were good ideas, and I tried them before I stumbled on the answer.

 

Glad you got it sorted. Nice find.