In ENA, manual topology is a facility that augments the automatic discovery of topology. It can be used to add additional links that (for whatever reason) were not discovered between devices being managed on the same server. It is often the case that links are not discovered around firewalls, because these rarely provide adequate topology information.
Links between devices that are not being managed on the same server are also not automatically discovered. The manual topology facility can be used to manually create such links on a consolidation server.
In ENA, you can manually define physical connections between two devices on a map, simply and directly from the map itself, which means you can instantly see the connection displayed. These custom connections are treated as if they were discovered via Auto Discovery, meaning that ENA creates an association between the source and destination devices using the discovery process, and will subsequently display its status as per the other existing connections on the map. Your custom connections are then listed together on the Manual Topology page for ease of reference and editing.