1-5To do… Use the command… RemarksEnable loopback testing loopback { external | internal } OptionalDisabled by default.z As for the internal loopback test and external loopback test, if a port is down (port state shown asDOWN), only the former is available on it; if the port is shut down (port state shown as ADM orAdministratively DOWN), both are unavailable.z The speed, duplex, mdi, and shutdown commands are not applicable during loopback testing.z With the loopback testing enabled, the Ethernet port operates in full duplex mode. With theloopback testing disabled, the original configurations will be restored.Configuring a Port GroupThe devices allow you to configure some functions on multiple ports at a time by assigning the ports toa port group in addition to configuring them on a per-port basis. This is helpful when you have toconfigure a feature in the same way on multiple ports.A port group is created manually and the settings you made on it apply to all group member ports. Notethat even though the settings are made on the port group, they are saved on a port basis rather than ona port group basis. Thus, you can only view the settings in the view of each port with the displaycurrent-configuration command or the display this command.Follow these steps to configure a manual port group:To do… Use the command… RemarksEnter system view system-view —Create a manual port group and entermanual port group viewport-group manualport-group-name RequiredAdd Ethernet ports to the manual portgroup group-member interface-list RequiredConfiguring Storm SuppressionYou can use the following commands to suppress the broadcast, multicast, and unknown unicast traffic.In port configuration mode, the suppression ratio indicates the maximum broadcast, multicast orunknown unicast traffic that is allowed to pass through a port. When the broadcast, multicast, orunknown unicast traffic over the port exceeds the threshold, the system will discard the extra packets sothat the broadcast, multicast or unknown unicast traffic ratio can drop below the limit to ensure that thenetwork functions properly.
