Operation Manual – MSTPH3C S3100-52P Ethernet Switch Chapter 1 MSTP Configuration1-38Rate Operation mode(half-/full-duplex) 802.1D-1998 IEEE 802.1t Latencystandard100 MbpsHalf-duplex/Full-duplexAggregated link 2 portsAggregated link 3 portsAggregated link 4 ports19151515200,000100,00066,66650,0002001801601401,000MbpsFull-duplexAggregated link 2 portsAggregated link 3 portsAggregated link 4 ports433320,00010,0006,6665,0002018161410 GbpsFull-duplexAggregated link 2 portsAggregated link 3 portsAggregated link 4 ports21112,0001,0006665002111Normally, the path cost of a port operating in full-duplex mode is slightly less than that ofthe port operating in half-duplex mode.When calculating the path cost of an aggregated link, the 802.1D-1998 standard doesnot take the number of the ports on the aggregated link into account, whereas the802.1T standard does. The following formula is used to calculate the path cost of anaggregated link:Path cost = 200,000,000 / link transmission rateWhere, “link transmission rate” is the sum of the rates of all the unblocked ports on theaggregated link measured in 100 Kbps.II. Configure the path cost for specific portsFollow these steps to configure the path cost for specified ports in system view:To do... Use the command... RemarksEnter system view System-view —Configure the path costfor specified portsstp interface interface-list[ instance instance-id ]cost costRequiredAn MSTP-enabled switchcan calculate path costsfor all its portsautomatically.
