This is the distinguished name of the network endpoint object associated with this internal backplane link. It matters on the internal Ethernet link that carries a blade's traffic from the chassis I/O Module up to a Fabric Interconnect over the backplane because it is the pointer that ties this physical-link record back to the logical network endpoint (e.g. a specific vNIC or uplink) that traffic on this link ultimately belongs to. Following the epDn on this backplane link is how an admin traces a link-level fault back to the specific blade adapter interface it will actually impact.