9.6 CHECK FOR CONNECTED EQUIPMENTTo check what devices are connected to the device being monitored:1. From the main window, select the device.2. Click the Equipment button.3. At the bottom of the main window, a box shows the ports where devices are connected and their MACaddresses.9.7 MIRRORING FUNCTIONPort mirroring is a method of monitoring network traffic that forwards a copy of each incoming and outgoingpacket from one port of the repeater to another port where the data can be studied. Port mirroring ismanaged locally and a network administrator uses it as a diagnostic tool.To set up port mirroring:1. Select the address of the device in the main window.2. Click the Mirroring button, a new screen appears.3. Click the checkbox to assign a a mirror port. A mirror port copies the incoming and outgoing traffic ofthe port.9.8 PORTS ON/OFFTo enable or disable ports:1. Select the address of the device in the main window.2. Click Ports On/Off, a new screen appears.3. Click the checkbox to enable or disable a port. A disabled port has an empty checkbox.9.9 VLANThe Virtual Local Area Network (VLAN) is a technique used to split an interconnected physical network intoseveral networks. This technique can be used at all ISO/OSI levels. The VLAN switch is mainly at OSI level 1(physical VLAN) which allows communication only between some Ethernet physical ports.Ports on the switch can be grouped into Physical VLANs to limit traffic flooding. This is because it is limited toports belonging to that VLAN and not to other ports.Port-based VLANs are VLANs where the packet forwarding decision is based on the destination MACaddress and its associated port. You must define outgoing ports allowed for each port when using port-based VLANs. The VLAN only governs the outgoing traffic so is unidirectional. Therefore, if you wish to allowtwo subscriber ports to talk to each other, you must define the egress port for both ports. An egress port isan outgoing port, through which a data packet leaves.To assign a physical VLAN to a set of ports:1. Select the address of the device in the main window.2. Click the VLAN button, a new screen appears.3. Use the checkboxes to select which ports will be in the same VLAN. By default all the ports share thesame VLAN.MiCOM P747 Chapter 8 - Redundant EthernetP747-TM-EN-1 271
