84Step Command Remarks3. Configure the hello timer.• In STP/RSTP/MSTP mode:stp timer hello time• In PVST mode:stp vlan vlan-list timer hello timeOptional.Use one of the commands.The default setting is 2seconds.4. Configure the max agetimer.• In STP/RSTP/MSTP mode:stp timer max-age time• In PVST mode:stp vlan vlan-list timer max-age timeOptional.Use one of the commands.The default setting is 20seconds.Configuring the timeout factorThe timeout factor is a parameter used to decide the timeout time, in the following formula: Timeout time= timeout factor × 3 × hello time.After the network topology is stabilized, each non-root-bridge device forwards configuration BPDUs tothe downstream devices at the interval of hello time to determine whether any link is faulty. If a devicedoes not receive a BPDU from the upstream device within nine times the hello time, it assumes that theupstream device has failed and starts a new spanning tree calculation process.Sometimes a device might fail to receive a BPDU from the upstream device because the upstream deviceis busy. If a spanning tree calculation occurs, the calculation can fail and also waste network resources.In a stable network, you can prevent undesired spanning tree calculations by setting the timeout factor to5, 6, or 7.To configure the timeout factor:Step Command Remarks1. Enter system view. system-view N/A2. Configure the timeout factor of thedevice. stp timer-factor factor 3 by default.Configuring the maximum port rateThe maximum rate of a port refers to the maximum number of BPDUs the port can send within each hellotime. The maximum rate of a port is related to the physical status of the port and the network structure.The higher the maximum port rate is, the more BPDUs will be sent within each hello time, and the moresystem resources will be used. By setting an appropriate maximum port rate, you can limit the rate atwhich the port sends BPDUs and prevent spanning tree protocols from using excessive network resourceswhen the network becomes unstable. H3C recommends you to use the default setting.To configure the maximum rate of a port or a group of ports:Step Command Remarks1. Enter system view. system-view N/A
