Users not logging into the PDC when the BDC was Down

[mcship]

I have a network of 700 machines with 1 BDC and 1 PDC, NT 4 SP 5 in the same subnet. Both machines are running DHCP with the load split close down the middle and both are running WINS and are replication partners. We lost our BDC due to hardware and while I was rebuilding a backup the users that were previous logged onto the BDC would not log into the PDC and pick up the a new IP, they received the error message "No domain controller found" Once the new BDC was online again users were able to log in fine. However my biggest problem is we will be switching our IPs out in a few weeks and I'm going to need to know this problem won't happen again. Any suggestions on taking down a BDC and forcing users to use the PDC?


Thanks

 

[bjsteeves]

Two things you may want to check on the PDC. First, is the NETLOGON Service running? If not, no one will be able to be authenicated on the PDC. Secondly, insure that the Replication is properly set up. The PDC should be set up as both Exporting and Inporting servers! Many sites forget to do this and if the user is authenticated by the PDC< there will be no logon scripts to run. Good Luck BJ Steeves - Computer Wizaerd At Large

 

[dxd]

For the sake of clarity.....were the clients unable to get an IP address from the PDC/DHCP? If you have 700 clients how large are the DHCP scopes? If the scopes are split between the PDC/BDC then when the BDC went down I would assume you would only have half of the IP's available....is that correct? Did you try an release the IP from any of the clients to see if they would pick up a new IP from the PDC? Doug
dxd_2000@yahoo.com

 

[mcship]

Yes the netlogon service was running and at the time repication was working, at least up untill the server crashed. We had users logged on the domain but it was just those that were logged into the BDC previously that had the problems.

 

[mcship]

When we released the IPs and attempted to renew we would get the same error message, &quot;no domain controller found&quot;. And yes the split on the IPs are nealy down the middle, we have 4 class Cs. And there were more then 100 IPs availbe when the BDC when down.