5-18 C HAPTER 5: A DVANCED M ANAGEMENTConfiguring STP on the SwitchCAUTION: You should not configure any STPparameters unless you have considerable knowl-edge and experience with STP.Configuring the STP Parameters of VLANsThe Switch has a completely separate STP system foreach VLAN that you have specified. Each VLAN hasits own Root Bridge, Root Ports and BPDUs.The VLAN STP screen allows you to set up andmanage an STP system for each VLAN on theSwitch. To access the VLAN STP screen:1 From the Main Menu, select SWITCH MANAGE-MENT. The Switch Management screen is displayed.2 In the Management Level field, choose VLAN.3 Choose the STP button. The VLAN STP screen is dis-played, as shown in Figure 5-16.The VLAN STP screen shows the following:VLAN ID 1 / 2 / 3 / ... 15 This field allows you tospecify the VLAN to be configured.If you are using STP, you cannot use VLAN 16. Also,if you are using AutoSelect VLAN Mode, you cannotuse VLAN 15. In these cases, the relevant VLANs areused internally by the Switch and are therefore notavailable.Topology Changes This read-only field shows thenumber of network topology changes that haveoccurred in the current VLAN.Figure 5-16 VLAN STP screenMax Age 6...40 This read-only field shows thetime (in seconds) that the Switch waits before tryingto re-configure the network. If the Switch has notreceived a BPDU within the time specified in thisfield, it will try to re-configure the network topol-ogy.Designated Root This read-only field shows theBridge Identifier of the designated Root Bridge.Hello Time 1...10 This read-only field shows thetime delay, in seconds, between the transmission ofBPDUs from the Switch.Root Cost This read-only field shows the path costfrom the Switch to the Root Bridge.
