XG Series User's Guide
Chapter 5 Command Reference
STP Information
223
5.8.1.2
stp age
Function
Set a maximum valid time of bridge configuration.
Available Model
XG0224 / XG0448 / XG0440DC / XG0440DCR / XG2600
Syntax
stp age <max_age>
Options
<max_age>
•
Maximum valid time
Specify a valid time of the BPDU information sent from the root bridge within the range
of 6 to 40 seconds.
The unit will be s (second).
Use Mode
Configuration mode (admin class)
Explanation
Set a valid time for the BPDU that the root bridge sends.
Receiving no BPDU frame from the root bridge within the max age time will lead this
device to begin sending BPDU as a root bridge.
Caution
<max_age> checks the relationship between the definition values of stp delay
<delay_time> and stp hello <time>.
•
Check with forward delay time
max age time <= 2
×
(forward delay time - 1.0 seconds)
•
Check with hello time
max age time >= 2
×
(hello time + 1.0 seconds)
If one or both of the above definition value is invalid, the set values of <max_age>,
<delay_time>, and <time> will be disabled.
The following shows definition conditions that are available for checking the relationship
between <max age>, <delay_time>, and <time>.
2
×
(forward delay time - 1.0 second) >= max age time >= 2
×
(hello time + 1.0 second)
Default
It is assumed that 20 seconds are set for the valid time of the BPDU sent by the root
bridge.
stp age 20s
