Always on Availability Groups on Azure Environment

[visithag]

I'm creating Always on availability group between two Azure vnets in same region. Both Vnets are peered. DC server and one SQL server on one vnet and different subnet. Secondary Vnet on another vnet in same region.  All the servers are running on Windows server 2016 and SQL 2016 Enterprises edition. I've created the cluster and getting these 3 error messages.

1. No matching network interface found for resource 'Cluster IP Address 10.2.0.0' IP address '10.2.0.8' (return code was '5035'). If your cluster nodes span different subnets, this may be normal.

2. Cluster resource 'Cluster IP Address 10.2.0.0' of type 'IP Address' in clustered role 'Cluster Group' failed.

Based on the failure policies for the resource and role, the cluster service may try to bring the resource online on this node or move the group to another node of the cluster and then restart it. Check the resource and group state using Failover Cluster Manager or the Get-ClusterResource Windows PowerShell cmdlet.

3. Cluster IP address resource 'Cluster IP Address' cannot be brought online because a duplicate IP address '192.168.0.132' was detected on the network. Please ensure all IP addresses are unique.

There is no duplicate IPs in the Venet. What can be the issue?

[#2]

@visithag 

How about the network, all can route through?

[#3]

Hi @visithag
There could be several issues causing these error messages, but based on your description, it seems like the most likely issue is related to the cluster IP address configuration and network communication between the different subnets. Here are some steps you can follow to troubleshoot and resolve the problem:

1- Ensure proper IP address configuration: Make sure that you've configured the correct IP addresses for the cluster and SQL Server instances. Verify that the cluster IP address, as well as the SQL Server IP addresses, belong to the correct subnet in each respective VNet.
2- Configure cluster IP addresses for each subnet: If your cluster nodes span different subnets, you should configure a unique cluster IP address resource for each subnet. You can do this using Failover Cluster Manager or PowerShell commands. For example, if you have two subnets, 10.2.0.0/24 and 10.3.0.0/24, you should have two cluster IP address resources, one for each subnet.
3- Configure static IP addresses: Ensure that both the primary and secondary SQL Server instances have static IP addresses assigned within their respective subnets. Dynamic IP addresses may lead to conflicts and unexpected behavior.
4- Verify network connectivity: Check the network connectivity between the two VNets and ensure that the necessary ports are open for cluster communication. You can use tools like Test-NetConnection in PowerShell or Azure Network Watcher to verify connectivity.
5- Validate the cluster configuration: Use the Failover Cluster Manager or the Test-Cluster cmdlet in PowerShell to validate the cluster configuration. This will help identify any issues with the cluster setup and provide guidance on how to resolve them.
6- Check for duplicate IP addresses: Although you mentioned that there are no duplicate IPs in the VNet, it's essential to double-check this. Verify that there are no other resources, such as virtual machines or network interfaces, with the same IP address as the cluster IP address or any SQL Server instance. You can use the Get-AzureRmNetworkInterface cmdlet in PowerShell to check for duplicate IP addresses in your Azure environment.
7- Review the Windows Event Log: Check the Windows Event Log on both cluster nodes for any additional information or error messages related to the cluster IP address or the SQL Server instances. This may provide more insight into the root cause of the issue.

By following these steps, you should be able to identify and resolve the issues causing the error messages. If you continue to experience problems, consider reaching out to Microsoft support for further assistance.