It depends what you mean by discovery. I am guessing that you would like to add any device under a /22 subnet to management in NSO. We sometimes refer to this as “existence discovery”, i.e. discovering the existence of network devices. The first thing you need to determine is what mechanism you will use to discover the devices. You could create a system that tries to ping all the devices in the subnet range, and records any address that responds. Then you need to try to figure out what type of device it is, so that you can select an appropriate NED. Quite often such a system would query one of the standard SNMP MIBs for this data, assuming of course that the devices are set up with consistent SNMP credentials. Then you can add the device to NSO, assuming again that they have known credentials for the NED communications, e.g. CLI userid/password.
So this is not something that’s built into NSO, but it’s quite commonly found in enterprise device managers. E.g. I remember we had this in Cisco Prime Infrastructure. Not sure if DNA Center has this too.
