TP-Link T1500-28PCT T1500-28PCTTL-SL2428PUN V3 User Guide - Page 332

Configuring Spanning Tree Figure 2-2 Configuring STP/RSTP Globally STP/RSTP Configurations Follow these steps to configure STP/RSTP globally: 1) In the Parameters Config section, configure the global parameters of STP/RSTP and click Apply. CIST Priority Specify the CIST priority for the switch. CIST priority is a parameter used to determine the root bridge for spanning tree. The switch with the lower value has the higher priority. In STP/RSTP, CIST priority is the priority of the switch in spanning tree. The switch with the highest priority will be elected as the root bridge. In MSTP, CISP priority is the priority of the switch in CIST. The switch with the higher priority will be elected as the root bridge in CIST. Hello Time Specify the interval between BPDUs' sending. The default value is 2.The root bridge sends configuration BPDUs at an interval of Hello Time. It works with the MAX Age to test the link failures and maintain the spanning tree. Max Age Specify the maximum time that the switch can wait without receiving a BPDU before attempting to regenerate a new spanning tree. The default value is 2. Forward Delay Specify the interval between the port state transition from listening to learning. The default value is 15. It is used to prevent the network from causing temporary loops during the regeneration of spanning tree. The interval between the port state transition from learning to forwarding is also the Forward Delay. Tx Hold Count Specify the maximum number of BPDU that can be sent in a second. The default value is 5. User Guide 309