Problem solve Get help with specific problems with your technologies, process and projects.

Why is my current mixed mode configuration making my network so slow?

I'm in the process of migrating two servers, s1 and s2, from NT4 Server SP6a to NT5 Advanced Server. I have one PDC (primary domain controller) and one BDC (backup domain controller).

The servers were set up by a previous sys admin, and thus are configured sort of odd. First, the machines are not complete replications of each other. There are some services installed on one that are not installed on the other, which makes for a maintenance nightmare, at best, and at worst means that the machines aren't really a PDC and BDC.

Anyway, when migrating, Microsoft recommends that you migrate the PDC first, followed by any BDC(s). I have already done this to the PDC and have left it mixed mode, at least until the migration is complete.

The PDC appears to be behaving itself...sort of. The user and computer account information did indeed migrate, but I have problems with it. Most of my Windows 98 machines can still log in just fine, with intermittent "domain is not available" errors, which the Active Directory client seems to have fixed. However, my NT5 and 5.1 clients can't log in most of the time, unless I log in as an administrator. Even users with equivalent credentials can't get in. In NT, it tells me, "The domain xyz is unavailable." All operating systems are as up-to-date as they can be.

I have checked Users and Computers, DNS, WINS and DHCP, and I can verify that my settings are (appear to be) correct. My DNS has the hostnames, and I have made sure that DHCP has enough IP addresses in the pool. WINS also appears to be working correctly, as my Windows 98 clients can see s1 right now.

S2 is the machine that I'm also fighting with. Integral to this problem is our order entry software, which resides on s2. After the migration to Windows 2000, when I went to use DCPROMO to add the DC as an additional controller to my domain, it kept telling me, "The RPC Server is unavailable." I have stopped and started the service on both machines numerous times, and I can't find the problem. I check my Event Viewer, and nothing relating to it comes up. I've even resorted to clearing the log and rebooting, but I still can't find the problem. This is bad because when I go to run my order entry software on my Windows 98 clients, it prompts me for a username and password to access s2. I understand from my research that when an upgraded server is in the middle of a promotion, it has a special password that it and the main domain controller has to sync between them.

Also, part of this problem is when my NT5 or 5.1 machines access my order entry software, they will drop my network down, until I force the application to end. I can run the application from the server just fine and have checked both root permissions and shared permissions, and they were fine. In short, my NT machines run very slow on my network all of a sudden, and I'm really confused about it.

In addition, when I can actually log in to the network on an NT client (as administrator) authentication is snappy, but it takes forever to load any personal settings...my profiles are all local, so it shouldn't be taking this long. Also, most of the time, no one else can get logged in from the NT machines.

Do you have any ideas what the problem is? I've read and reread several MCSE books and browsed the Knowledge Base. Basically right now I'm all but clueless as to what the problem is. Can you help?

I would check the following:

  • Check that the ServerName.FQDN of the PDC and BDC match the Active Directory domain name. If your domain is MyCompany.com then when you right click My Computer, click Properties and click the Network Identification tab, you should see your server name as s1.MyCompany.com. Prior to the upgrade you should have either cleared the FQDN (AD fully qualified domain name) or made it match what you were going to call the resulting domain. If you did not, then the DCs will behave very oddly until it is corrected. Unfortunately, you will need to demote each server in turn to correct it. This also means you will have to shuffle the FSMOs around. See KB article Q257623, Domain controller's domain name system suffix does not match domain name.

  • Run NETDIAG.EXE on the DCs. This will perform a thorough check of all the DNS and network connectivity. If you are having a less obvious problem with DNS or WINS this may weed it out for you.

  • Check replication between the two DCs. The event log is a good start (File Replication Service and the Directory Service logs). Also look in the Active Directory Sites and Services for replication configuration issues.
  • Dig Deeper on Microsoft Active Directory

    Start the conversation

    Send me notifications when other members comment.

    Please create a username to comment.