7NOTE:• On an interface that is physically down, you can only perform internal loopback testing. On an interfaceadministratively shut down, you can perform neither internal nor external loopback testing.• The speed, duplex, mdi, and shutdown commands are not available during loopback testing.• During loopback testing, the Ethernet interface operates in full duplex mode. When you disableloopback testing, the interface returns to its duplex setting.• Loopback testing is a one-time operation, and is not recorded in the configuration file.Configuring jumbo frame supportAn Ethernet interface might receive some frames larger than the standard Ethernet frame size (called"jumbo frames") during high-throughput data exchanges such as file transfers. Usually, an Ethernetinterface discards jumbo frames. With jumbo frame support enabled, the interface can process frameslarger than the standard Ethernet frame size yet within the specified range.In interface configuration mode (Ethernet interface view or port group view), you can set the length ofjumbo frames that are allowed to pass through the Ethernet interface.• If you execute the command in Ethernet interface view, the configuration takes effect only on theinterface.• If you execute the command in port group view, the configuration takes effect on all ports in the portgroup.Follow these steps to configure jumbo frame support in interface view or port group view:To do… Use the command… RemarksEnter system view system-view —Enter Ethernet interfaceviewinterface interface-typeinterface-number —Configure jumbo framesupport jumboframe enable [ value ]RequiredBy default, the switch allows jumbo frames within9216 bytes to pass through Ethernet interfaces.If you set the value argument multiple times, thelatest configuration takes effect.Configuring a port groupSome interfaces on your switch might use the same set of settings. To configure these interfaces in bulkrather than one by one, you can assign them to a port group.You create port groups manually. All settings made for a port group apply to all the member ports of thegroup.Even though the settings are made on the port group, they are saved on each interface basis rather thanon a port group basis. You can only view the settings in the view of each interface by using the displaycurrent-configuration or display this command.Follow these steps to configure a manual port group:
