stp timer max-age
Function
The stp timer max-age command sets the Max Age of a switching device, that is, the BPDU aging time on a port of the switching device.
The undo stp timer max-age command restores the default setting.
By default, the Max Age of a switching device is 2000 centiseconds.
Parameters
| Parameter | Description | Value |
|---|---|---|
| max-age | Specifies the BPDU aging time on a port of the switch. |
The value ranges from 600 to 4000 in centiseconds with a step of 100. |
Usage Guidelines
Usage Scenario
In a spanning tree, the device closer to the root bridge is the upstream device of another connected device.
Precautions
The value of the Max Age set on the root bridge is advertised to other devices of the same spanning tree using BPDUs. Then it becomes the MaxAge value of all devices in the spanning tree.
The timer MaxAge value takes effect for only the CIST and does not take effect for MSTIs.
2 x (Forward Delay - 1.0 second) >= Max Age
Max Age >= 2 x (Hello Time + 1.0 second)
Running the stp bridge-diameter command to set the network diameter is recommended. After the stp bridge-diameter command is run, the switching device sets optimum values for the three parameters, Hello Time, Forward Delay, and Max Age.
