Configuring Spanning Tree
Note:
To prevent frequent network flapping, make sure that Hello Time, Forward Delay, and Max Age
conform to the following formulas:
2*(Hello Time + 1) <= Max Age
•
2*(Forward Delay - 1) >= Max Age
•
This example shows how to configure the priority of the switch as 36864, the Forward
Delay as 12 seconds:
Switch#configure
Switch(config)#spanning-tree priority 36864
Switch(config)#spanning-tree timer forward-time 12
Switch(config)#show spanning-tree bridge
State
Mode
-------
-----
Enable Rstp
Switch(config)#end
Switch#copy running-config startup-config
2.2.3 Enabling STP/RSTP Globally
Follow these steps to configure the spanning tree mode as STP/RSTP, and enable spanning
tree function globally:
Step 1
configure
Enter global configuration mode.
Step 2
spanning-tree mode { stp | rstp }
Configure the spanning tree mode as STP/RSTP.
stp
rstp:
Step 3
spanning-tree
Enable spanning tree function globally.
Step 4
show spanning-tree active
(Optional) View the active information of STP/RSTP.
Step 5
end
Return to privileged EXEC mode.
Priority
Hello-Time
--------
------
36864
2
: Specify the spanning tree mode as STP .
Specify the spanning tree mode as RSTP .
Fwd-Time
Max-Age
--------
--------
12
20
STP/RSTP Configurations
Hold-Count
Max-Hops
---------
--------
5
20
Configuration Guide
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