1-10To do… Use the command… RemarksConfigure the interval for portloopback detectionloopback-detectioninterval-time timeOptional30 seconds by defaultEnter Ethernet port view interface interface-typeinterface-number —Enable loopback detection on aport loopback-detection enable RequiredDisabled by defaultEnable loopback detectioncontrol on a trunk port or ahybrid portloopback-detection controlenableOptionalDisabled by defaultEnable loopback detection in allthe VLANs permitted on thetrunk or hybrid portloopback-detection per-vlanenableOptionalEnabled only in the defaultVLAN(s) with trunk port orhybrid portsz Loopback detection on a given port is enabled only after the loopback-detection enablecommand has been configured in both system view and the interface view of the port.z Loopback detection on all ports will be disabled after you configure the undo loopback-detectionenable command in system view.Configuring the MDI Mode for an Ethernet PortThe optical interfaces of SFP ports do not support this function.Two types of Ethernet cables can be used to connect Ethernet devices: crossover cable andstraight-through cable. To accommodate these two types of cables, an Ethernet port on a device canoperate in one of the following three Medium Dependent Interface (MDI) modes:z Across modez Normal modez Auto modeAn Ethernet port is composed of eight pins. By default, each pin has its particular role. For example, pin1 and pin 2 are used for transmitting signals; pin 3 and pin 6 are used for receiving signals. You canchange the pin roles through setting the MDI mode. For an Ethernet port in normal mode, the pin rolesare not changed. For an Ethernet port in across mode, pin 1 and pin 2 are used for receiving signals; pin3 and pin 6 are used for transmitting signals. To enable normal communication, you should connect thelocal transmit pins to the remote receive pins. Therefore, you should configure the MDI modedepending on the cable types.
