If it isn't, theremay be a problem with thephysicalconnectionfrom the networkadapteronyourhostto the gateway (for example, a faultyswitchport, cable, network card).
This system enables users to connect one half-length PCIe 2.0 adaptercard to the Mac mini via a Thunderbolt cable, while allowing the connection of additional Thunderbolt peripherals to the daisy-chain Thunderbolt port.