Devices are not pingable, but show 100% uptime

Devices are not pingable, but show 100% uptime

Hi,
 
I have discovered a number of devices in OpManager that are not pingable, that do not have monitoring enabled on them and with IP addresses not recognised by anybody within my organisation.  I would happily remove these from OpManager, except that they show as being 100% available.
 
Does anybody know of any reason as to why this might be happening?
 
Thanks,
 
SM

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