3Com Router 3000 Ethernet FamilyConfiguration Guide Chapter 3 Bridge Configuration3Com Corporation3-163.2.4 Configuring the Bridge to Support STPI. Disabling/enabling STP on portsTo have STP parameters take effect on a bridge port, you must enable STP on it.Perform the following configuration in interface view.Table 3-15 Disable/enable STP on the portOperation CommandDisable STP on the port bridge-set bridge-set stp disableEnable STP on the port undo bridge-set bridge-set stp disableBy default, STP is enabled on the port.II. Specifying the STP version supported by a bridge-setSTP has multiple standards, which are not compatible. To prevent bridging loops, thecommunicating parties must use the same STP standard.Currently, 3Com Routers only support IEEE STP.Perform the following configuration in system view.Table 3-16 Specify the STP version supported by a bridge-setOperation CommandSpecify the STP version supported by abridge-set bridge bridge-set stp ieeeDisable a bridge-set to support STP undo bridge bridge-set stp ieeeBy default, bridge-sets support IEEE STP.III. Assigning a priority to the bridge (optional)The ID of a bridge consists of two parts: bridge priority and bridge MAC address.During a spanning tree calculation in a network, the bridge with the lowest ID iselected as the root. The process is as follows:z Compare the priorities of the bridges in the network. The one with the lowestbridge priority is elected as the root.z In case multiple bridges in the network have the same priority, compare theirMAC addresses and elect the bridge with the lowest MAC address as the root.When STP is enabled, changing the priority of a bridge may cause spanning treerecalculation.Perform the following configuration in system view.
