Windows service cluster 2016 in Azure getting: Cluster network name resource failed registration of one or more associated DNS name(s) because the a DNS server could not be reached.

Question

I have 3 VMS in Azure. 3 vms in same Vnet and subnet.

1 DC with domain foo.bar.local 10.83.48.4
VM1 2016 with SQL joined to that domain with name: VM1. foo.bar.local 10.83.48.5
VM2 2016 with SQL joined to that domain with name: VM1. foo.bar.local 10.83.48.6

I created a failovercluster with those 2 nodes. This will later will be configured for SQL always on.
Service cluster SQL1.foo.bar.local with ip 10.83.48.9 was created successfully and 2 nodes are up and running.

But then when I see event logs and cluster logs I´m getting:

Cluster network name resource failed registration of one or more associated DNS name(s) because the a DNS server could not be reached. 

Cluster Network name: 'Cluster Name'
DNS Zone: 'reddog.microsoft.com'
DNS Server: '10.83.48.4'

If I go to DC I can see that both nodes and cluster service are registered ok.

Now neither of the nodes have internet access. It´s like the cluster service is not able to connect to DC even though both nodes had configured DC Ip as their dns (the only DNS that it was configured)

I can see that cluster service it´s trying to reach reddog.microsoft.com instead of 10.83.48.4 the DNS configured in both boxes.

Is there something I can check to fix this?

thank you!

Answer 1

Hi,

Thanks for your posting!

Based on your descriptions, I suppose your issue is more related with Azure network configuration.

Firstly, I can offer you some information which may be useful for better understanding your issue.

When you use your own name resolution solution, the suffix provided by DHCP is not supplied to VMs because it interferes with other DNS architectures (like domain-joined scenarios). Instead, Azure provides a non-functioning placeholder (reddog.microsoft.com). You can get more information about using your own DNS server:

https://learn.microsoft.com/en-us/azure/virtual-network/virtual-networks-name-resolution-for-vms-and-role-instances#name-resolution-that-uses-your-own-dns-server

https://stackoverflow.com/questions/51162336/change-dns-suffix-on-azure-vm

(Please note: Information posted in the given link is hosted by a third party. Microsoft does not guarantee the accuracy and effectiveness of information.)

By default, reddog.microsoft.com will be the specific DNS suffix for the ethernet adapter for Azure VM. When a VM joins an AD domain however the primary DNS suffix will automatically be changed for the IP configuration to that of the AD domain which overrides others and adapter DNS suffix ignored.

In this case, even though you see reddog.microsoft.com as the DNS suffix for the adapter as long as the IP configuration primary suffix is that of the domain there is no further action needed. Make sure you joined the domain and added the AD domain suffix correctly. Also, you can restart your Azure VM to take the domain changing effect.

Secondly, if you need more professional explaination, you may need to post your issue on our Azure Q&A forum without windows-server or windows-server-clustering tags and new technical supporter responsible for Azure will come to help you as soon as possible. Here is the link:

https://learn.microsoft.com/en-us/answers/topics/azure-virtual-machines.html

Thanks for your understanding! And don't forget to support us by clicking "Accept Answer"!

BR,
Joan

--------------------------------------------------------------------------------------------------------------------

If the Answer is helpful, please click "Accept Answer" and upvote it.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Answer 2

Hi @JiayaoZhu thanks for your reply. I added the AD domain suffix and restarted vms. However they continue been able to have access to internet.

I also just created case with support you suggested:

https://learn.microsoft.com/en-us/answers/questions/389264/windows-2016-cluster-nodes-unable-to-reach-interne.html

thanks.-