STP(Spanning-Tree Protocol) Timers
Hello timer
Hello timer is the time between each Bridge Protocol Data Unit(BPDU) that is sent on a port. This is equal to two seconds by default, but can be adjusted between 1 ~ 10 seconds.
Max Age
Max age timer controls the maximum length of time a bridge port saves its configuration BPDU information. This is 20 seconds by default and can be turned to adjusted between 6 ~ 40 seconds
Forward Delay
Forward delay timer is the time spent in the listening and learning stage. 15 seconds is default, but it can be adjusted between 4 ~ 30 seconds.