Exchange stops working when one of our domain controllers is down

[Brazen]

We have one Exchange 2000 server and 2 Windows 2000 domain controllers. The original DC and Exchange server were set up before I got here. I set up the new DC for a backup.

When the original DC goes down (as it tends to due from time to time), then people have problems using Outlook (sending email, opening the GAL, things like that). I don't have any idea why this is happening. The only clue I can find is that under AD Sites and Services, the original DC has a folder under it called "Exchange Settings" with "Active Directory Connector" under that. From what I understand, the ADC should only be used when you have Exchange 5.5 in your environment, which this place never had, so it should not even be there in the first place.

So I'm trying to figure out how to keep Exchange working when the original DC goes down. Thanks for any help...

 

[funkbass81]

make sure the second domain controller is also a global catalog

 

[Brazen]

You are talking about the check box under Sites and Services right? Yes, they BOTH have global catalog checked.

 

[Brazen]

Could there maybe be something else that isn't letting Exchange or Outlook know that the new DC is also a global catalog?

 

[ITJunkie]

Not sure if this will help your situation or not but open Exchange System Manager. Under "Recipients" click on "Recipient Update Services" and see which domain controller the two entries are pointing to. Chances are it is pointing to the DC that's down. I believe you can either manually point it to the other DC or force it to update by right-clicking and choosing Update Now. That should force it to look at the other DC.
Like I said, this may not address your problem so you might Check This first for more info.

Good luck,

~Bill

 

[Smilin]

bounce the netlogon service on your 'missing' DC. It will reregister all SRV records including GC.

 

[Brazen]

Originally posted by: Smilin
bounce the netlogon service on your 'missing' DC. It will reregister all SRV records including GC.

Smilin, I think you might be misunderstanding. Outlook and Exchange work fine right now, while the old DC is powered on and running. The problem is for instance, this morning the old DC froze up and had to be rebooted (a 30 minute process), and while it was frozen and rebooting, Exchange/Outlook would not work. I'll try bouncing the netlogon service, but I think you are answering the wrong question?

 

[Brazen]

Originally posted by: ITJunkie
Not sure if this will help your situation or not but open Exchange System Manager. Under "Recipients" click on "Recipient Update Services" and see which domain controller the two entries are pointing to. Chances are it is pointing to the DC that's down. I believe you can either manually point it to the other DC or force it to update by right-clicking and choosing Update Now. That should force it to look at the other DC.
Like I said, this may not address your problem so you might Check This first for more info.

Good luck,

~Bill

I checked Recipient Update Services, and they are both pointed at the new DC (I seem to remember manually moving these some time ago).

I want to get rid of the old DC, but I'm afraid after running dcpromo, things will stop working, just like when it is powered off.

 

[Brazen]

I wonder if this is the cause of my problem? Maybe all I have to do is have the users restart their computers and/or restart the exchange server. We do use Outlook 2000 so this could be applicable.

 

[dedwards]

Here's something else to check -

In the Exchange System Manager, under Yourexchangeserver - Properties, look at the Directory Access tab. Select Global Catalog Servers in the Show field and see if your new DC is listed. You can set the Exchange server to discover these automatically, or you can add it manually.

DE

 

[Smilin]

Originally posted by: Brazen

Originally posted by: Smilin
bounce the netlogon service on your 'missing' DC. It will reregister all SRV records including GC.

Smilin, I think you might be misunderstanding. Outlook and Exchange work fine right now, while the old DC is powered on and running. The problem is for instance, this morning the old DC froze up and had to be rebooted (a 30 minute process), and while it was frozen and rebooting, Exchange/Outlook would not work. I'll try bouncing the netlogon service, but I think you are answering the wrong question?

I may be misunderstanding sure. I think you are misunderstanding me though.

You have two global catalogs. A global catalog is needed. You shut down one and the other can't be found. That indicates that either one GC is screwed up, or the client doesn't know it's a GC. A client learns of GCs via DNS SRV records. Either check your DNS records by hand or bounce the netlogon service on the DC and it will automatically reregister it's DNS SRV records provided you are allowing dynamic updates.

This may not be the issue at all of course but it is definately worth checking.