Identifying the Uniqueness of Workstations
While performing a scan in ServiceDesk Plus, the criteria that helps to identify the uniqueness of the workstations is in the following order,
Agent ID ( only for Agent based Scan)
With the help of these criteria, ServiceDesk Plus differentiates between workstations and assumes the Agent ID, Service Tag, MAC Address and Workstation Name to be unique for each workstation. If any criteria match for two workstations, then the workstation details will be overwritten.
The procedure in which the workstations are overwritten for each criteria
are explained below,
Consider two workstations, Machine A and Machine B with similar Service Tag as 12345. The names of the workstations are MachineA.domain.com and MachineB.domain.com respectively. Consider that only Machine A has been scanned by the application. Upon scanning Machine B, since the Service Tag is the same, the workstation details of Machine A will be overwritten by that of Machine B.
The Solution: Configuring Invalid Service Tags
If the Service Tag is not configured properly by the OEM, then many machines would have similar Service Tags. In this case one workstation would be overwritten by another during scan. Such service tags can be ignored during scan by adding them under the Invalid Service Tag list.
This configuration is under Admin tab -> General Settings (Under Discovery section).
In general, while scanning workstations, the application will first look for Service Tag. If the Service Tag is empty the next parameter i.e., the computer name will be considered and workstations will be overwritten accordingly. Consider the workstation, MachineA.domain.com, is already available in the application. If another machine with same name is scanned then the details in former workstation (MachineA.domain.com) will be replaced by the latter.
The third criteria which the application looks for while overwriting workstations are the MAC Addresses. Consider a workstation with different name and Service Tag, but with same MAC address as the one already available in the application. On performing a scan, the details of the existing workstation will be replaced by the newly scanned workstation.
In certain environments there are possibilities of MAC address being the same in many machines (VMware or machines connected through VPN). Unique MAC address identification can be enabled or disabled under Admin tab -> General Settings (Under Discovery section).
Scenarios: When does the machine be renamed with _old
When the workstations are swapped in the network.
Consider two workstations, MACHINE-A with service tag ST-1 and MACHINE-B with ST-2. Both the workstations are swapped in the network. On swapping the workstations configurations is, MACHINE-A with ST-2 and MACHINE-B with ST-1. If you scan MACHINE-A, then the workstation MACHINE-B will be overwritten as MACHINE-A and the workstation MACHINE-A will be renamed as MACHINE-A_old. If you scan MACHINE-B again, it will overwrite the MACHINE-A_old as MACHINE-B.
The workstation is already discovered with a valid Service Tag but scanned again with a different service tag. In this case ServiceDesk Plus will rename the existing workstation with '_old' and add the machine again with the new Service Tag.
In certain cases, the workstations might be discovered with valid service tag. But during its life cycle, you might change the motherboard of the workstation, thus changing the service tag. In this case, the existing workstation is renamed with _old and the workstation with the new service tag is added again.
The workstation MACHINE-A with service tag ST-1 is already scanned in the network. Another workstation, MACHINE-A with service tag ST-2 is added to the network. If you scan the workstation MACHINE-A again, it will rename the workstation as MACHINE-A_old and will add the newly added workstation as MACHINE-A.
In case of VMware machines, when the host is changed, the Service Tag gets changed too.
Workstations overwritten with _old during Agent Based Scan:
If you have enabled Agent Base Scan, then the Agent ID (a unique ID which is created on all workstations when the agent is installed on them for the first time) will be considered as a unique parameter for fetching the workstation details.
If the agent is deployed through an 'Image', then the same Agent ID will be copied to all the client machines. This in turn, will create duplicate entries for the workstations when scanned and subsequently appends the previous workstation with _old. To overcome this issue, we request you to uninstall the agent completely from the registry and deploy it through AD GPO.