There are several ways to populate the network model with the assets that represent your monitored network. Most enterprises use a combination of these methods:
Caution: Do not import assets with an ampersand (&) in the name. The ArcSight resource framework does not support that character in asset and zone names.
When importing assets using a scanner import connector, the automatically-created asset group name is based on the new asset's zone name. If that name already exists in the same folder, then instead of importing the asset there, as you would expect, the connector imports the asset into either a standard System Asset Group or a higher level custom Asset Group to prevent a folder name conflict.
Ensure that if you manually create asset range names, they do not match the Zone names of assets that you intend to import using an asset scanner connector.