NT 4.0 Domain - PDC

[melissasue 0]

Hi,

 

I am hoping that someone would be able to help me. My query will most probably not make much sense as I am not that knowledgable with networking and with NT Servers.

 

I work for a transcription company where we transcribe live audio from the courts. A couple of weeks ago our NT Server fell over, it was over five years old. A new motherboard, cpu and power supply was installed, data was copied off the hard drive, NT reinstalled and then the data copied back on to the hard drive.

 

Once the server has had its extreme make over I hook it back up to the network and can be found on the network. Now this domain has 7 machines that log on to the server, each machine is Windows NT. Each machine logs in as monitor onto the domain, but the following error message comes up:

 

"A domain controller for your domain could not be contacted. You have been logged on using cached account info. Changes to your pofile since you last logged on may not be available".

 

My question is, what does this mean? I have gone through help and can find nothing about this, or I could be looking in the wrong areas and how do I fix this little problem?

 

If anyone could help me, I would be so grateful.

 

Thanks and regards

 

Melissa Sue

[DosFreak 2]

This is basically saying that your workstations cannot find the PDC. What likely happened is that since you rebuilt your PDC the account information for those computers was lost. You'll need to remove the workstations from the domain (it still thinks it's connected to the domain when it's not) and re-add them to your new PDC.

 

Hopefully when you had the server rebuilt, it was rebuilt as a PDC and not standalone.

[mnas 0]

About MAC addresses: I don't believe the MAC address is of much importance to the domain structure. If I'm not misstaken it is only used by network hardware (routers, swtches, etc) and the network protocol of the OS.

 

If it were critical to the PDC role you wouldn't even be able to change a failed NIC in a domain controller. Or use multiple NIC's in a PDC.

 

Am I right? Feel free to correct me if I'm not.

[dirtydave931 0]

Originally posted by mnas:

Quote:

About MAC addresses: I don't believe the MAC address is of much importance to the domain structure. If I'm not misstaken it is only used by network hardware (routers, swtches, etc) and the network protocol of the OS.

 

If it were critical to the PDC role you wouldn't even be able to change a failed NIC in a domain controller. Or use multiple NIC's in a PDC.

 

Am I right? Feel free to correct me if I'm not.

 

That sounds correct to me.

 

[mnas 0]

It would be nice to get some more info about how the server is set up. Was the OS was rebuilt from old backups or not? If the OS is installed without the use of a recovery disc or some other kind of backup, all accounts will be gone. Every account in WinNT has a SID, a unique ID-number. If you install a domain controller and recreate the accounts manually the SID's will be different. The domain part of the SID will also be different.

 

Example:

 

Let's say we have a domain with an NT4 PDC called PDC1 hosting a domain called MYDOMAIN and a few clients named CLIENT1, CLIENT2, etc... Then one day the PDC fails and we have no backup of the account database. So a reinstallation of the OS follows and we set the server up as a PDC for a domain called MYDOMAIN. Now this is important: Although the domain we created is named exactly the same as the old one it is NOT the same domain. There is a lot of information behind that name. A lot of unique identifiers are generated when the domain is created. The Netbios name MYDOMAIN is used kind of like an alias for something much more complex.

 

So, our client machines still think they are connected to a domain called MYDOMAIN. But, they generate messages saying that they are unable to contact a PDC for the domain MYDOMAIN. Why is that? There IS a domain called MYDOMAIN! I set it up myself! I know it!

 

Now, as stated above. It is NOT the same domain anymore. The new PDC doesn't know anything about the old one.

 

What we need to do is reconfigure the clients to belong to the new domain. This is done by removing them from the old domain and put them in a workgroup. And then connect them to the new domain. When a workstation (client) connects to a domain controller the DC creates a computer account for the workstation. This makes it possible for the client to ask the DC for information needed to process a login.

 

As before, correct me if I'm wrong.

[melissasue 0]

This is exactly what has happened. Except the domain is called MAGISTRATE.

 

Let's say we have a domain with an NT4 PDC called PDC1 hosting a domain called MYDOMAIN and a few clients named CLIENT1, CLIENT2, etc... Then one day the PDC fails and we have no backup of the account database. So a reinstallation of the OS follows and we set the server up as a PDC for a domain called MYDOMAIN. Now this is important: Although the domain we created is named exactly the same as the old one it is NOT the same domain. There is a lot of information behind that name. A lot of unique identifiers are generated when the domain is created. The Netbios name MYDOMAIN is used kind of like an alias for something much more complex.

 

So, our client machines still think they are connected to a domain called MYDOMAIN. But, they generate messages saying that they are unable to contact a PDC for the domain MYDOMAIN. Why is that? There IS a domain called MYDOMAIN! I set it up myself! I know it!

 

Now, as stated above. It is NOT the same domain anymore. The new PDC doesn't know anything about the old one.

 

What we need to do is reconfigure the clients to belong to the new domain. This is done by removing them from the old domain and put them in a workgroup. And then connect them to the new domain. When a workstation (client) connects to a domain controller the DC creates a computer account for the workstation. This makes it possible for the client to ask the DC for information needed to process a login.

 

To do the above do I need to also create accounts on the server first, then go into local machines switch them to a workgroup, restart the computer, then go back and connect them to the magistrate domain and then create an account to the server from the local machine. I would be very grateful for your advise.

 

As before, correct me if I'm wrong.

 

[melissasue 0]

Sorry guys, Im getting a bit confused with how to reply to threads etc, pls bear with me.

 

Thanks mnas, this is exactly what has happened. To reconfigure the clients to the new domain, even though it is named the same, do i have to disconnect the network drives that I have mapped, then go into properties take the clients off the workstation, place them in a gamon workgroup, restart the machine. Once I have logged back go back into properties then reconnect the client to the magistrate domain, do I then create an account on the domain once I have typed in the domain name? And if I do, I need to actually create the clients name on the server first, yeah?

 

Thanks to everyone for your help, I have learnt quite a lot this morning.

 

Regards

[DosFreak 2]

Originally posted by melissasue:

Quote:

To reconfigure the clients to the new domain, even though it is named the same, do i have to disconnect the network drives that I have mapped, then go into properties take the clients off the workstation, place them in a gamon workgroup, restart the machine. Once I have logged back go back into properties then reconnect the client to the magistrate domain, do I then create an account on the domain once I have typed in the domain name? And if I do, I need to actually create the clients name on the server first, yeah?

 

Thanks to everyone for your help, I have learnt quite a lot this morning.

 

Regards

 

 

You can create the workstation accounts on the server and then connect your workstation to the domain but I prefer doing it all from the workstation since you have to go to the workstation anyway to connect it to the domain if you create the computer account anyway.

 

Simple delete the inactive machine accounts that you have already created for those machines. Now go to each workstation, disconnect from the old domain and reconnect to the new domain. A prompt will ask for your Username/password to verify that you have Rights to add a workstation to the domain, enter user/pass, hit OK and you should get a message box stating that you have been added to the domain.

 

[Edited by dosfreak on 2005-01-06 02:18:56]

 

[melissasue 0]

Thanks everyone for your help and advice....it worked. I'm extremely happy.

 

Regards

 

Melissa Sue