Discovery groups simplify the process of working with a large number of devices and their corresponding IP addresses/hostnames and discovery credentials. For example, if you have set of four user/password credentials used among twenty devices, using a discovery group allows you to enter each set of credentials and all of the IP addresses/hostnames, and the discovery group will match the correct credentials to each device.
Procedure
What to do next
Review your devices and credentials to avoid lockout of devices due to multiple attempts of incorrect credentials. You can create groups in such a way that devices have a minimal set of credentials to be tried against. You can use common public-private key pairs for multiple devices.