Spanning Tree Protocol Timers

STP convergence requires three timers, as follows:

• Hello Timer -The hello time is the interval between BPDUs. The default is 2 seconds but can be modified to between 1 and 10 seconds
• Forward Delay Timer -The forward delay is the time that is spent in the listening and learning state. The default is 15 seconds but can be modified to between 4 and 30 seconds
• Max Age Timer -The max age is the maximum length of time that a switch waits before attempting to change the STP topology. The default is 20 seconds but can be modified to between 6 and 40 seconds

Note: The default times can be changed on the root bridge, which dictates the value of these timers for the STP domain