There is a setting in Spectrum which allows to ignore device's FQDN.
How CA Performance Center (CA PC) will handle the device names in Spectrum where there is no FQDN, while CA PC have devices with FQDN?
Below is an explanation of some of the workflows involved in the CA Performance Center / Spectrum integration around this matter.
Spectrum and Data Aggregator (DA) are both data sources of CA PC, and both can contribute devices.
If Spectrum contributes a device to CA PC it includes the IP address and name for the model. At that point CA PC would display the name for the
model as it is seen in Spectrum.
Data Aggregator can also discover devices contributed by other data sources, if enabled to do so, and in such case the Data Aggregator name will take precedence over
Spectrum's name.
In this case the IPs for the devices would be pushed to Data Aggregator, and if the discovery profile was configured with the hostname as the
primary naming convention, and the DNS resolution done at the DC level provides the FQDN, then we'd expect them to be the same.
If the DA discover using the sysName, or the hostname is different than what Spectrum has, then CA PC will show the name for the device based on how DA discovered it.