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We were checking out a computer earlier that was having some software problems, and found that somehow it was no longer listed in AD. It was still able to logon to the domain, and domain users had no problems logging in.
We've seen this happen with a couple of other computers. Anyone know what would be causing this?
I think AD gets its computer list from DHCP. So, devices on a static IP don't show. Certainly devices that have been off for long enough for the lease to expire don't show.
We don't use DHCP. AD adds computers to its list whenever a domain admin joins it to the domain. We can rejoin it to the domain, and the computer will show back up. We're all scratching our heads on this one.
You're confusing AD with DDNS.Quote:
Originally Posted by Aardpsymon
On a windows domain a computer needs to be registered to it. This usually happens when you "join" a domain, the computer account gets created automagicly.
Delstar, maybe you should turn on some auditting? Perhaps someone is removing the computer account, or it may "time-out". I've seen both happen. The security logs can show the needed info, if you turn on audits that is.
Nothing was in the logs about it, and we know none of us removed it. The computer in question is used daily, and all of our computers are set to reboot at midnight, so I'm not sure how it would time-out.
Haven't figured that one out either, just know it happens from time to time.
Do you audit these events? They aren't by default and nothing would show up in the logs.
delstar,
yeah, no resolution here either. I've suffered a similar situation where my account has just disappeared from AD. No error messages, nothing in the event viewer. It's happened twice over a year and I still have no clue what's causing it.
SirDice : yes, we audit events such as this
ShagDevil : we've seen it happen to 2 different computers, but others may have been affected and we just haven't found them yet
After a bit of googling, nobody else seems to know what's causing it, either. We did notice a large number of the people that did have this problem made note of the fact that they use McAfee, which we also use, but I have no idea why that would be causing problems like this.
Are you guys running McAfee Antivirus or Firewall? I've seen issues where reinstalling this fixes the problem. Have also seen it work with Norton/Symantec products as well...worth a shot.
well it is going to get the computer name over netbios since you are using AD. Maybe those systems have firewalls or maybe some one changed the name of them recently?
Wazz : Antivirus. Just re-joining it to the domain fixed it, but we want to know what caused it in the first place.
oofki : AD won't add the computer unless a domain admin does it. Netbios has nothing to do with it (as far as I know). None of our systems have software firewalls enabled, and no one outside of our IT department can change the name of the computer (plus, it hasn't been changed since it's been moved into this building)
I've had this happen in the past with a bunch of things. DFS subscriptions, computer names, site to site replication subscriptions (NTDS), etc.
For me, It is normally problem with AD replication. During replication, that object becomes "orphaned" and it is moved to the lost and found folder. Have you looked in the "lost and found" container? From there, you can either move them back the the correct place or delete them and recreate them. I tend to just recreate them because I don't know why they were lost to begin with.
Do you have a lot of replication errors or kcc errors? The easiest way I've found to get rid of replication or kcc errors is to demote the AD server with problems, and let that replication take place on all other AD servers. This is normally the time where I'll also get an unsucessful removal of a domain controller and have to use ntdsutil and adsi edit. After all that, I'll normally wait a couple of hours for good measure. I'm on a pretty slow WAN, so I like to be safe... Then I'll rejoin it and let it get all new replica info.
We've had problems like this probably 3 or 4 times since moving from nt4 2000 mixed mode and again after moving to 2000 native. I suspect a couple of the problems were due to some of the AD servers being on different SPs at different times. Since then, I've been very careful to make sure they all have very similar SP and update levels along with configs.