Consolidated Platform Configuration Guide, Cisco Ios Release 15.2(4)E (Catalyst 2960-X Switches - Cisco Catalyst 2960 series Configuration Manual

DETAILED STEPS
Command or Action
Step 1
enable
Example:
Switch> enable
Step 2
configure terminal
Example:
Switch# configure terminal
Step 3 interface interface-id
Example:
Switch(config)# interface
gigabitethernet1/0/2
Step 4 spanning-tree portfast [trunk]
Example:
Switch(config-if)# spanning-tree
portfast trunk
Step 5
end
Example:
Switch(config-if)# end
What to Do Next
You can use the spanning-tree portfast default global configuration command to globally enable the PortFast
feature on all nontrunking ports.
Related Topics
PortFast, on page 288
Purpose
Enables privileged EXEC mode. Enter your password if prompted.
Enters the global configuration mode.
Specifies an interface to configure, and enters interface configuration
mode.
Enables PortFast on an access port connected to a single workstation or
server. By specifying the trunk keyword, you can enable PortFast on a
trunk port.
Note
By default, PortFast is disabled on all interfaces.
Returns to privileged EXEC mode.

Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)

How to Configure Optional Spanning-Tree Features
To enable PortFast on trunk ports, you must use the
spanning-tree portfast trunk interface configuration command.
The spanning-tree portfast command will not work on trunk
ports.
Make sure that there are no loops in the network between the
trunk port and the workstation or server before you enable
PortFast on a trunk port.
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