User's Manual

235
Users Manual of CS-6306R
19.2.3.7 Configuring STP Time Parameters
The following are STP time parameters:
 Hello Time:
The interval to send the configuration message to the designated port when the switch functions as the
network root.
 Forward Delay:
Time that the port needs when it changes from the Blocking state to the learning state and to the
forwarding state in STP mode.
 Max Age:
The maximum live period of the configuration information about the spanning tree.
To reduce the shock of the network topology, the following requirements for the time parameters must be
satisfied:
 2 x (fwd_delay - 1.0) >= max_age
 max_age >= (hello_time + 1) x 2
Command Purpose
spanning-tree mstp hello-timeseconds
Sets the parameter Hello Time.
The parameter seconds is the unit of Hello Time,
ranging from 1 to 10 seconds. Its default value is
two seconds.
no spanning-tree mstp hello-time Resumes Hello Time to the default value.
spanning-tree mstp forward-timeseconds
Sets the parameter Forward Delay.
The parameter seconds is the unit of Forward
Delay, ranging from 4 to 30 seconds. Its default
value is 15 seconds.
no spanning-tree mstp forward-time Resumes Forward Delay to the default value.
spanning-tree mstp max-ageseconds
Sets the parameter Max Age.
The parameter seconds is the unit of Max Age,
ranging from 6 to 40 seconds. Its default value is
20 seconds.
no spanning-tree mstp max-age Resumes Max Age to the default value.
It is recommended to modify STP time parameters by setting root or network diameter, which ensures correct
modification of time parameters.
The newly-set time parameters are valid even if they do not comply with the previous formula’s requirements.
Pay attention to the notification on the console when you perform configuration.