Online Domain controller not authenticating 2

[Flashgordon]

Hi All

We've got 2 Windows 2000 domain controllers, one of which we've been having problems with and I've been re-starting it regularly. The problem is, while it is re-booting (and that takes 15 mins because it's an Exchange server) some users are unable to log in to the domain, even though the other domain controller is still online. I've even rebooted the other DC in case there was a problem with that, there are no error messages in the event logs. This morning when we tried it, one user was able to log in, but the next user wasn't. I was thinking this may be something to do with which DC they look for. Any ideas?
thanks

Andy.

 

[Flashgordon]

Additional info: The re-booting server is also DNS server. I don't know if that's significant.

 

[ntinlin]

It is very significant.

Are you using AD integrated DNS? If not why not?

If you are, check DHCP scopes to make sure the other DC is down as a secondary DNS server.

A W2K client will ask DNS for its closest DC/GC to authenticate logon and if your DNS DC is down it obviously can't.
I think - not positive - that client also keeps a note of where it authenticated last and will try that if it doesn't get a DNS response. (Somebody feel free to shoot me down in flames) - That could be why some are getting on and others aren't.

Neill

 

[Micron1090]

You'll also need to install and configure DNS on that second domain crontroller. Then like ntinlin posted, you'll need to make sure your clients are aware of that secondary DNS server.

 

[Flashgordon]

Thanks guys, I am running ADIDNS on the first server, but DNS is not installed on the second one. I never would have found that, thanks again.
Andy.