This string holds the fully qualified Distinguished Name (Dn) that UCS Manager's information model uses as the unique address of this fabric-interconnect network interface. Because this fabric-interconnect network interface is a physical network interface on a UCS fabric interconnect, its Dn is what scripts, XML-API calls, and cross-referencing objects (like another object's peerDn field) use to point straight at this exact instance rather than at a plain, possibly duplicated name. A value for this fabric-interconnect network interface might look like 'fabric/lan/A/if-1-1', with the exact segments reflecting where it sits under the fabric interconnect in the object tree.