3Com Switch 8800 Configuration Guide Chapter 38 MSTP Region-configuration38-23Table 38-14 Configure a port as an edge port or a non-edge portOperation CommandConfigure a port as an edge port. stp edged-port enableConfigure a port as a non-edge port. stp edged-port disableRestore the default setting of the port asa non-edge port. undo stp edged-portYou can configure a port as an edge port or a non-edge port with either of theearlier-mentioned measures.After configured as an edge port, the port can fast transit from blocking state toforwarding state without any delay. You can only set the port connecting with theterminal as an edge port.In the case that BPDU protection has not been enabled on theswitch, the configured edge port will turn into a non-edge port again when it receivesBPDU from other ports. In the case that BPDU protection is enabled, the port will bedisabled. The configuration of this parameter takes effect on all the STIs. In other words,if a port is configured as an edge port or non-edge port, it is configured the same on allthe STIs.It is better to configure the BPDU protection on the edged port, so as to prevent theswitch from being attacked.Before BPDU protection is enabled on the switch, the port runs as a non-edge portwhen it receives BPDU, even if the user has set it as an edge port.If BPDU protection is enabled on the switch, the port is disabled. Only the networkadministrators can enable the port.By default, all the Ethernet ports of the switch have been configured as non-edge ports.Note:It is better to configure the port directly connected with the terminal as an edge port,and enable the BPDU function on the port. That is, to realize fast state-transition andprevent the switch from being attacked.38.2.11 Configuring the Path Cost of a PortPath Cost is related to the speed of the link connected to the port. On the MSTP switch,a port can be configured with different path costs for different STIs. Thus the traffic fromdifferent VLANs can run over different physical links, thereby implementing theVLAN-based load-balancing.You can configure the path cost of a port in the following ways.
