Simple definition
A World Wide Node Name identifies a Fibre Channel node, distinct from the WWPN that identifies an individual port.
Purpose and use
A WWNN, World Wide Node Name, identifies a node in Fibre Channel architecture.
How does it work?
It differs from a WWPN, World Wide Port Name, which identifies a port; one device can expose several port identities.
Example and verification
During SAN presentation, verify which identifier each tool and rule expects.
Points to watch
Confusing WWNN and WWPN can cause incorrect host, zoning or storage-access associations.
In short
Track node identity separately from the identities of its ports.