1. A method, comprising: maintaining a discovery database including information on at least one network, and, for each network, information on entities in the network and a status of the entities; generating a user interface display indicating the entities in one network that are available and unavailable; receiving user selection of at least one entity in the network that is displayed as unavailable, wherein at least one displayed unavailable entity is not selected; receiving user selection to remove the selected at least one entity; and removing from the discovery database information on the selected at least one entity and any underlying entities within the selected entity in response to the user selection to remove the selected at least one entity.