I ran into an interesting issue when changing the DNS settings on a Windows Server 2008 R2 server not too long ago:
Each time I tried to change the DNS settings I’d hop back into the NIC settings to review my changes and they would be gone. A few googles didn’t help much until I saw this remark from a post on the web:
Tried that too…no dice…I have found the cause and resolved the issue. Our network is running Symantec Endpoint Protection for antivirus/malware protection. There is a feature in version 12.1 called Sonar which protects against network intrusions. The policy on the affected workstation was set to block DNS changes…hence the blank DNS settings when I tried to manually set them. I changed the policy to allow DNS changes, entered the IP Subnet Gateway and DNS, rebooted, and…It is working now! Thank you Cameron O and LemP for your assistance.
Not that it directly helped, but it reminded me that Umbrella will change the DNS settings and point them internally. Therefore, it makes sense that I wouldn’t be able to see or make DNS changes.
Solution: Stop the Umbrella service to get this to work.
Once the service was stopped I could make my changes and things were fine.
Hope this helps,