Operation Manual – Stack-ClusterH3C S3100 Series Ethernet Switches Chapter 2 Cluster2-9Note:z By default, the management VLAN interface is used as the network managementinterface.z There is only one network management interface on a management device; anynewly configured network management interface will overwrite the old one.VI. Tracing a device in a clusterIn practice, you need to implement the following in a cluster sometimes:z Know whether there is a loop in the clusterz Locate which port on which switch initiates a network attackz Determine the port and switch that a MAC address corresponds toz Locate which switch in the cluster has a faultz Check whether a link in the cluster and the devices on the link comply with theoriginal planIn these situations, you can use the tracemac command to trace a device in the clusterby specifying a destination MAC address or IP address.The procedures are as follows:1) Determine whether the destination MAC address or destination IP address is usedto trace a device in the clusterz If you use the tracemac command to trace the device by its MAC address, theswitch will query its MAC address table according to the MAC address and VLANID in the command to find out the port connected with the downstream switch.z If you use the tracemac command to trace the device by its IP address, the switchwill query the corresponding ARP entry of the IP address to find out thecorresponding MAC address and VLAN ID, and thus find out the port connectedwith the downstream switch.2) After finding out the port connected with the downstream switch, the switch willsend a multicast packet with the VLAN ID and specified hops to the port. Uponreceiving the packet, the downstream switch compares its own MAC address withthe destination MAC address carried in the multicast packet:z If the two MAC addresses are the same, the downstream switch sends a responseto the switch sending the tracemac command, indicating the success of thetracemac command.z If the two MAC addresses are different, the downstream switch will query the portconnected with its downstream switch based on the MAC address and VLAN ID,and then forward the packet to its downstream switch. If within the specified hops,a switch with the specified destination MAC address is found, this switch sends aresponse to the switch sending the tracemac command, indicating the success ofthe tracemac command. If no switch with the specified destination MAC address
