Some SQL Server Instances show the Physical Hostname under Hosts and others will show the Network Name (4305657)

In the Databases dashboard, some SQL Server Instances show the physical hostname (aka short name) in the Host field, and others will show the FQDN (Fully Qualified Domain Name) of the Network Name (aka Virtual Name). If it's showing the FQDN of the Network Name, it doesn't show the metrics for all the members of the cluster.

This often happens when the physical hostname is not resolvable, but the FQDN of the Network Name is.

When the SQL Server agent wizard is testing the OS connectivity, it will try using the Network Name (aka Virtual Name) of the SQL Server instance if the physical server name fails to resolve to an IP address.

A very common cause for this issue is the DNS Suffix Search List associated to the NIC (network interface) used by the FglAM. This is an OS-level configuration setting.

For Windows, this DNS Suffix Search List is listed when running this command:

ipconfig /all

For most Linux distros, this configuration can be found in /etc/resolv.conf:

sudo cat /etc/resolv.conf

RESOLUTION 1

Add the DNS suffix to the NIC's DNS Suffix Search List used by the FglAM so that both the FQDN and the physical hostname are resolvable.

RESOLUTION 2

Create a WindowsAgent for each node manually. Reference can be found here.

Resolving DNS resolution issues is out of the scope of this article. A network administrator or system administrator should be able to advise which solution best fits the environment.