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Catalyst 2900 Series XL and Catalyst 3500 Series XL Software Configuration Guide
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Chapter 6 Configuring the System
Configuring STP
Changing the Forwarding Delay Time
Beginning in privileged EXEC mode, follow these steps to change the forwarding
delay time. The stp-list is the list of VLANs to which the STP command applies.
STP Port States
When a port is not forwarding due to STP, it can be in one of these states:
•
Blocking—Port is not participating in the frame-forwarding process and is
not learning new addresses.
•
Listening—Port is not participating in the frame-forwarding process, but is
progressing towards a forwarding state. The port is not learning addresses.
•
Learning—Port is not forwarding frames but is learning addresses.
•
Forwarding—Port is forwarding frames and learning addresses.
•
Disabled—Port has been removed from STP operation.
•
Down—Port has no physical link.
•
Broken—One end of the link is configured as an access port, and the other
end is configured as an 802.1Q trunk port, or both ends of the link are
configured as 802.1Q trunk ports but have different native VLAN IDs.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
spanning-tree [vlan stp-list]
forward-time seconds
Specify the forwarding time for the specified spanning-tree
instance.
The forward delay is the number of seconds a port waits
before changing from its STP learning and listening states
to the forwarding state. Enter a number from 4 to 200.
The default for IEEE is 15 seconds; the default for IBM is
4 seconds.
Step 3
end
Return to privileged EXEC mode.
Step 4
show spanning-tree
Verify your entry.
