we have built 2 node windows cluster in Azure VM. the VIP is not able to connect from App server

Question

Hi Team,

We have built 2 node windows cluster in Azure VM. the VIP is not able to connect from App server with port number .

the cluster is able to failover and able to connect SQL inside the DB cluster server. SQL port also configured correctly on both the node.

Can you advise on this issue and guide me.

Answer 1

Hi Saravanan Rajendiran,

Thank you for posting in the Microsoft Community Forums.

Verify the VIP configuration:

Ensure that the VIP has been properly configured in the cluster and has been assigned to a cluster service or a corresponding Network Name.

Check the network configuration of the cluster to ensure that the subnet where the VIP is located is on the same network or a routable network as the client or application server to which you are trying to connect.

Check the firewall settings:

On the Azure VM, check the Windows firewall settings to ensure that inbound connections are allowed from the application server IP address to the appropriate port of the VIP.

If an Azure Network Security Group (NSG) is applied to the VM's subnet or network interface, check that the NSG rule allows traffic on that port.

Port Listening and Connection Testing:

On each node of the cluster, use the netstat -an | findstr <port number> command to check if the port is being listened to.

Use telnet VIP <port number> or other network tools to try to connect to that port on the VIP from the application server to see if the connection is successfully established.

Check the SQL Server configuration:

Although you mentioned that the SQL port is configured correctly on both nodes, make sure that SQL Server is configured to listen on the VIP instead of the physical IP address.

Check the network configuration of SQL Server to ensure that the TCP/IP protocol is enabled and that it is configured to listen on all IP addresses or at least VIPs.

View cluster and SQL Server logs:

Check the cluster and SQL Server related logs in the Windows Event Viewer for any error or warning messages.

In particular, look for errors related to network connections, port conflicts, or permissions.

Azure load balancer (if applicable):

If you are using an Azure load balancer in your architecture (such as an on-premises load balancer), check that the load balancer's backend pool contains the correct VMs and that the health checks are successful.

Ensure that the load balancer's rules allow traffic from the application servers to the VIPs.

Network routing and ACLs:

Check the routing table in the Azure virtual network to ensure that there are no routing rules preventing traffic from reaching the VIP.

Check if there are any Azure Access Control Lists (ACLs) or security policies that might be blocking traffic.

DNS Resolution:

Ensure that the application server is able to properly resolve the DNS name of the VIP (if a DNS name is used).

Best regards

Neuvi