Operation Manual – Port Basic ConfigurationH3C S7500 Series Ethernet Switches Chapter 1 Port Basic Configuration1-5Note:z If you specify a source aggregation group ID, the system will use the port with thesmallest port number in the aggregation group as the source.z If you specify a destination aggregation group ID, the configuration of the sourceport will be copied to all ports in the aggregation group and thus all ports in the groupwill have the same configuration as that of the source port.1.1.5 Configuring Loopback Detection for a PortLoopback detection is used to monitor if loopback occurs on a port.After you enable loopback detection on Ethernet ports, the switch can monitor ifexternal loopback occurs on them. If there is a loopback port found, the switch will put itunder control.z If loopback is found on an access port, the system disables the port, sends a Trapmessage to the terminal and removes the corresponding MAC address forwardingentry.z If loopback is found on a trunk or hybrid port, the system disables the port, sends aTrap message to the terminal and removes the corresponding MAC addressforwarding entry.Follow these steps to configure loopback detection for a port:To do… Use the command… RemarksEnter system view system-view —Enable loopbackdetection globallyloopback-detectionenableOptionalBy default, loopback detectionis disabled globally.Set the time interval forport loopbackdetectionloopback-detectioninterval-time timeOptionalThe default interval is 30seconds.1.1.6 Enabling the System to Test Connected CableYou can enable the system to test the cable connected to a specific Ethernet electricalport. The test result will be returned in five seconds. The system can test whether thereis short circuit/open circuit on the RX and TX directions of the cable, and the length ofthe faulty cable.Follow these steps to enable the system to test the cable connected to a specific port:
