I have got a pretty strange issue on a domain controller. Environment is:
- Windows 2008R2 Std Server + all updates
- One DC + a few Windows clients joined to that AD
On that DC was Symantec Endpoint Protection 12.1.x installed. Somebody uninstalled it and that caused that the network cards lost their IP config (read: ipconfig /all showed NO interfaces anymore but in the control panel I was able to see and configure them). Thanks to Symantec's CleanWipe tool I was able to remove some left overs of SEP (I guess it was their network protection driver) and regained IP connectivity.
Unfortunately that killed my DNS and also my AD services.
When I open the DNS Add-In, I get the same error as described in:
Microsoft DNS – Access is Denied. Event log: The DNS server was unable to open Active Directory
I checked my hosts file and re-added the localhost entries. That did not do the trick.
I checked name resolution then:
ping localhost -> not found
ipconfig /flushdns && ipconfig /displaydns
-> localhost is in the cache!
Other test – I have added a new host (8.8.8.8 www.google.com) to the "hosts" file:
ipconfig /flushdns && ipconfig /displaydns
-> I see google.com and 8.8.8.8 in the cache
ping www.google.com -> host not found
It seems that the hosts file is loaded correctly into the DNS cache but not used?
This blocks pretty much all tries to configure the DNS as I cannot open the DNS Addin.
Update #1:
NIC Configuration is static,
- IP = 10.45.0.1
- Netmask = 255.255.255.0
- GW = 10.45.0.254
- DNS = 10.45.0.1
No static routes configured.
Note, AFTER the Symantec Cleanup I have cleaned out the whole Windows network config:
netsh winsock resetnetsh int ip reset
Any advice welcome!
Best Answer
Uninstall the NIC from device manager and let it reinstall clean. (Remove and rescan) Make sure DNS is set to listen on all interfaces not just the static IP, be cautious of rebooting if you don't have the AD Recovery password you could get stuck without DNS and unable to login because of it.