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I ran dcpromo to demote a W2K3 dc. The wizard completed without a hitch. However, there are now a few anomalies:

Launching nslookup from the remaining dc (W2K8 R2) gives the result- Default Server: Unknown

nslookup from a client pc gives - Server Unknown, Address: ip address of the demoted server and the message "Unknown can't find computername: no response from server"

The DNS Role has been removed from the old dc but DNS on the new dc is still showing entries for the old dc (eg under DomainDNSZones & ForestDNSZones). This article http://support.microsoft.com/kb/216498 suggests running ntdsutil to clean up metadata but the article is written for W2K3 SP1 or lower and the new dc is W2K8. And the first section of the article also suggests that removing the old dc from Servers in AD Sites and Services will do the same thing on W2K8 anyway.

Can I remove the old dc from Sites and Services and remove the old dc entries from DNS? Or should I run metadata cleanup from ntdsutil? And most importantly I suppose, will this resolve the issues I am having?

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Launching nslookup from the remaining dc (W2K8 R2) gives the result- Default Server: Unknown

Server Unknown is a totally harmless message. It means that there is no PTR record in your rDNS zone for the ip address of the DNS server(s) configured in the TCP/IP properties on the host that you're running nslookup from. It could also mean that you don't have a rDNS zone, but based on what you've said that doesn't sound like the case. Verify that the DNS servers listed in the TCP/IP properties of the NIC are the correct servers and that you have an rDNS zone and that PTR records for these servers exist. Note: An rDNS zone and PTR records are completely optional and aren't required for the proper operation of AD/DNS in any way, shape, or form.

nslookup from a client pc gives - Server Unknown, Address: ip address of the demoted server and the message "Unknown can't find computername: no response from server

It sounds like you haven't removed the old servers ip address from the DNS servers in the TCP/IP properties of the client and added the new server ip address. Verify that the DNS servers listed in the TCP/IP properties of the NIC are the correct servers and that you have an rDNS zone and that PTR records for these servers exist.


Running metadata cleanup isn't going to clean up your DNS zone(s) of the old server. You'll need to do that manually. Metadata cleanup will clean the old server out of AD, but not DNS.

While performing metadata cleanup with ntdsutil should be the same in W2K8, this article suggests that it can be accomplished completely with the GUI tools, so go with that method.

http://technet.microsoft.com/en-us/library/cc816907(WS.10).aspx#bkmk_graphical

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Thanks Joe - yes, I hadn't removed the old ip address from the client pc but when I change to automatic choice of DNS server the old dc shows in ipconfig. I actually don't know if I have an rDNS zone - I have a Reverse Lookup Zone. Is that the same thing? –  Rory Jan 28 '12 at 19:58
    
Yes an rDNS zone is "shorthand" for Reverse Lookup Zone. If your clients are getting their ip address information automatically then that means that you're using a DHCP server and need to change the DNS servers in your DHCP scope options or server options. These are the DNS servers that are assigned to the clients by the DHCP server. You need to remove the old server and add the new server. –  joeqwerty Jan 28 '12 at 20:21
    
worked a charm - appreciate your help Joe –  Rory Jan 29 '12 at 17:48
    
Glad to help... –  joeqwerty Jan 29 '12 at 18:08

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