TRENDnet TPE-1620WS User's Guide - Page 27

TRENDnet User's Guide • External Cost: This defines a metric that indicates the relative cost of forwarding packets to the specified port list. Port cost can be set automatically or as a metric value. Define a value between 1 and 200000000 to determine the external cost. The lower the number, the greater the probability the port will be chosen to forward packets. The default port cost: 100Mbps port = 200000. Gigabit port = 20000. • State - Displays the current port spanning tree state. o Blocking - A blocking state does not allow network traffic to be sent or received on a the port except for BPDU data. A port with a higher path cost to the root bridge than another on the switch causes a switching loop and is placed in the blocking state by the Spanning Tree algorithm. The port's state may change to the forwarding state if the other links in use fail and the Spanning Tree algorithm determines the port may transition to the forwarding state. o Listening - This state occurs on a port during the convergence process. The port in the listening state processes BPDUs and awaits new information that would cause the port to return to the blocking state. o Learning - While the port does not yet forward frames (packets), in this state the port does learn source addresses from frames received and adds them to the filtering (switching) database. o Forwarding - A port that both receives and sends data. This indicates normal operation. STP continues to monitor the port for incoming BPDUs that indicate the port should return to the blocking state to prevent a loop. o Disabled - This state is not strictly part of STP. However, a network administrator can manually disable a port. • Edge: Indicates if a port is connected to an edge device in the network topology or not. Selecting the Forcetrue parameter designates the port as an edge port. Edge ports cannot create loops, however an edge port can lose edge port status if a topology change creates a potential for a loop. An edge port normally should not receive BPDU packets. If a BPDU packet is received, it automatically loses edge port status. Selecting the Forcefalse parameter indicates that the port does not have edge port status. Selecting the Auto parameter indicates that the port have edge port status or not have edge port status automatically. The default setting for this parameter is Auto. TPE-1620WS • P2P: Choosing the Forcetrue parameter indicates a point-to-point (P2P) shared link. P2P ports are similar to edge ports however they are restricted in that a P2P port must operate in full-duplex. Like edge ports, P2P ports transition to a forwarding state rapidly thus benefiting from RSTP. A P2P value of Forcefalse indicates that the port cannot have P2P status. Auto allows the port to have P2P status whenever possible and operate as if the P2P status were true. If the port cannot maintain this status, (for example if the port is forced to half-duplex operation) the P2P status changes to operate as if the P2P value were Forcefalse. The default setting for this parameter is Auto. • Restricted Role: Toggle between True and False to set the restricted role state of the packet. If set to True, the port will never be selected to be the Root port. The default value is False. • Restricted TCN: Toggle between True and False to set the restricted TCN of the packet. Topology Change Notification (TCN) is a BPDU that a bridge sends out to its root port to signal a topology change. If set to True, it stops the port from propagating received TCN and to other ports. The default value is False. • Migrate: Indicates if the port is configured to accept RSTP and STP BPDUs. 4. Click Save Settings to Flash (menu). 5. Click Save Settings to Flash (button), then click OK. Note: This step saves all configuration changes to the NV-RAM to ensure that if the switch is rebooted or power cycled, the configuration changes will still be applied. © Copyright 2013 TRENDnet. All Rights Reserved. 27