Sync BDC over WAN

[Bob_M]

Hello All,

I can not a BDC to synchronize with a PDC across the WAN. It works fine when I do it manually in Server Manager. They don’t however seem to sync automatically. The PDC seems to automatically sync to a local BDC just fine as determined by event viewer on the PDC.

Event viewer on the PDC or BDC report no errors. Only the successful syncs when I do it manually.

I had to put an LMHOST file on the BDC in order for it to see the PDC. I wonder if I have to put one on the PDC so it will see the BDC across the WAN. Strange no error though.

Any ideas.

[gavsta]

You are in fact correct. If you are not using WINS or DNS you will need to maintain LMHOSTS that contain entries for all your PDCs and BDCs on every domain controller in the domain.

This should then resolve your problem.
Domain Controllers do not just communicate for domain stuff there are browse lists they maintain as well, this data will also be passed across your WAN links.

Gav.

[Bob_M]

Hi Gav,

We are going to try the LMHOST file today but over the weekend the BDC and PDC synced once by themselves.

What would have caused that?

[Bob_M]

Gav,

One more question, does the PDC need to be rebooted for domain Sync to take place properly? I read so where that evertime Netlogin starts on a PDC it reregisters all the BDC's.

Bob

[gavsta]

There is a setting in the registry which sets intervals at which domain synchs take place etc. not all of these events are logged when successful unless chosen. I believe the default interval is 15 mins. but this may change if the network link is detected as a slow connection such as WAN, frame relays and dial up.

you can also use this knowledgebase link:
<a target="_blank" href=http://support.microsoft.com/default.aspx?scid=kb;EN-US;q149664>http://support.microsoft.com/default.aspx?scid=kb;EN-US;q149664</a>

for more info and for verification of the synch.

Gav.

[Bob_M]

Hi Gav,

Though I would report back for anyone following the thread.

I have it all working now. I am not sure exactly what did it but I did two things that seem to help. 1) I put a LMHOSTS on all three domain controllers. 2) I issued a Net accounts /sync command from the problem BDC. This seem not only to sync the SAMs but two other Databases as well, (builtin and LSA??). Now they seem to sync automatically when a change is made to the domain. This is evident by the Netlogin entries in Event viewer. Interestingly, no errors were ever reported in the PDC's event viewer when the sync's were not occurring. You would think something like, "BDC Test was not found", especially since the PDC is supposedly pulsing the BDC's ever 5 min to see if it is online.

I know what you said about NT sencing the slow link but this WAN is a private T1.

When you install a BDC to you have to go into the PDC's server manager and add the computer first. I know when I ran the net accounts /sync it did the machine database. That might have been the key.

Thanks Bob

Bob